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M I S S I O N     M A N A G E R S   
Scott Lever, Mission manager Mike Seibert, Mission manager Al Herrera, Mission manager
Scott Lever Mike Seibert Al Herrera
P R E V I O U S    M I S S I O N    M A N A G E R S
Matt Keuneke, Mission Manager Cindy Oda, Mission Manager Rich Morris, Mission Manager Bill Nelson, Mission manager
Matt Keuneke Cindy Oda Richard Morris Bill Nelson
Byron Jones, Mission Manager Mark Adler, Mission Manager Leo Bister, Mission manager Beth Dewell, Mission Manager
Byron Jones Mark Adler Leo Bister Beth Dewell
Emily Eelkema, Mission Manager Jeff Favretto, Mission Manager Soina Ghandchi, Mission Manager Andy Mishkin, Mission Manager
Emily Eelkema Jeff Favretto Saina Ghandchi Andy Mishkin
Art Thompson, Mission Manager Rick Welch, Mission Manager Colette Lohr, Mission Manager Dan Gaines, Mission Manager
Art Thompson Rick Welch Colette Lohr Dan Gaines

sol 333-345, December 23, 2004: Spirit Eats a Potato-Sized Rock

Spirit finished work at a rock called "Wishstone," then continued to make slow progress up "Husband Hill." Wishstone is different than any rock Spirit previously studied either on the plains or in the hills. Scientists and engineers used the miniature thermal emission spectrometer to find similar rocks for further study.

A potato-sized rock got caught in Spirits's right rear wheel on sol 339, causing the wheel to stall and ending the drive for that sol. Small moves of the wheel on subsequent sols dislodged the rock, but the rock remains close to the wheel, so the team is planning small, careful steps to move the wheel away from the rock so it will not become jammed again. Spirit remains in excellent health.

Sol-by-sol Summaries:

Atmospheric observations using the miniature thermal emission spectrometer, navigation camera, and panoramic camera continue on a daily basis.

On sol 333, Spirit used the brush of the rock abrasion tool brush to scrub a small section of Wishstone and took microscopic images of the spot. Spirit then placed the alpha particle X-ray spectrometer on the spot for collecting data overnight.

On sol 334, Spirit removed the alpha particle X-ray spectrometer and then used the rock abrasion tool to drill into Wishstone. After taking more microscopic images, Spirit placed the alpha particle X-ray spectrometer on the hole for an overnight observation.

On sol 335, Spirit removed the alpha particle X-ray spectrometer from the hole and replaced it with the Mössbauer spectrometer. Spirit also started a long series of Mössbauer observations that would last until the early morning of sol 337.

On sol 337, Spirit stowed its robotic arm, then bumped backwards to take final images of Wishstone and the rock abrasion tool hole. Spirit was commanded to drive 15 meters (49 feet), but drove only about 6 meters (20 feet) due to experiencing slippage of up to 80 percent on uphill portions of the drive.

On sol 338, Spirit drove 8 meters (26 feet) with 25 meters (82 feet) of commanded motion. Spirit saw up to 95-percent slip on some of the drive segments due to sandy terrain and the rover's tilt of 15 to 20 degrees.

On sol 339, the rover team attempted another 25-meter (82-foot) drive. This was cut short at the start when the right rear wheel ingested a potato-sized rock. The rock apparently jammed between the inner part of the wheel and the drive mechanism, causing the drive current to exceed a pre-set limit, resulting in a safe motor stall.

Sol 340 - Spirit made observations with the miniature thermal emission spectrometer to seek other rock targets similar to Wishstone. Turning the right rear wheel about 60 degrees successfully un-jammed the rock, but it remained inside the wheel.

Sols 341, 342 and 343 were planned as a combined three-sol plan that included observations with the miniature thermal emission spectrometer each sol. On sol 341, Spirit used its microscopic imager and its Mössbauer spectrometer to examine disturbed soil in front of the rover. It switched to the alpha particle X-ray spectrometer overnight to gather more compositional information about the same target. On sol 342, Spirit performed a mid-day tool change back to the Mössbauer spectrometer. On sol 343, the rover stowed the robotic arm and took images with the panoramic camera of targets that had been observed with the miniature thermal emission spectrometer. Spirit then performed a small maneuver but did not significantly change the position of the rock in the wheel.

Sol 344 - Spirit performed more remote sensing and did a maneuver that lifted the right rear wheel slightly out of a hole, but the rock remains partially in the wheel. The wheel is about one-third buried in the soft soil, making it difficult for the rock to escape until the wheel gets out of the hole.

Sol 345 - Spirit successfully executed another small maneuver to get the right rear wheel out of hole and get the rock out of the wheel, but more steps will be required. The rover also used the panoramic camera and miniature thermal emission spectrometer to acquire information about nearby targets. Sol 345 ended on Dec. 22.


sol 326-332, December 14, 2004: Trekking Toward 'Husband Hill'

Spirit drove five of the last seven days, continuing its trek towards the top of "Husband Hill." Spirit's intermediate goal is a ridge dubbed "Larry's Lookout," which is roughly 75 meters (246 feet) away. Getting there using Spirit's current path will be a challenge given the sand, slope, and rocks in this area. Spirit paused for a set of weekend observations of a rock called "Wishstone." Total odometry for the mission is now 3,944 meters (2.45 miles).

The amount of electric current drawn by the motor on the right front wheel is in the normal range. Near the end of Spirit's long series of drives from "Bonneville Crater" to the "Columbia Hills," the right front wheel began to draw roughly twice the current of the other five wheels. The increased current prompted engineers to limit the use of this wheel to preserve its life. Since arriving at the hills, Spirit has had relatively few driving days. The rover team's current working theory on this problem suggests that the recent rest periods have allowed the lubricant in this wheel to redistribute, causing the current draw to return to normal. Periodic rest days will be included in rover drivers' plans, and Spirit will alternate forward and backward driving to keep the lubricant in all of the wheels more evenly distributed.


sol 306-325, December 07, 2004: The Holiday Spirit is on Mars

During the 19 sols ending on sol 325 (Dec. 1), Spirit continued to explore in the "Columbia Hills." Spirit reached a position northeast of a ridge called "Machu Picchu" and began crossing a 200-meter-wide (656-foot-wide) flat saddle area.

The amount of electric current drawn by the motor of the right front wheel continues to be a concern. However, during a recent drive the current draw was closer to normal than it had been in preceding weeks. Engineers will continue to limit use of this wheel by driving backwards when terrain allows, dragging it 90 percent of the time.

Between sols 306 and 325, Spirit finished shooting a Thanksgiving panorama with the panoramic camera; investigated new rock targets "Corn," "Cocomama," and "Butter" with the science instruments; and continued to drive eastward between the "West Spur" and an area where the terrain slopes back upward toward "Husband Hill."

Spirit successfully completed about 80 meters (262 feet) of driving, bringing the total mission traverse to 3.82 kilometers (2.37 miles).


sol 292-305, November 18, 2004: Three hundred sols and counting!

Spirit remains in excellent health and has survived more than 300 martian days on the red planet.

With the Sun still relatively low on the horizon in the early spring season on Mars, rover drivers are forced to seek driving routes that keep the rover and its solar panels tilted northward for energy reasons. That constraint, plus the rocky terrain, will challenge rover drivers in the coming weeks.

Over the last few weeks, the electrical "brakes" on Spirit's right-front and left-rear steering actuators (motors) apparently failed to disengage during drive attempts. The most likely cause of this anomaly is the buildup of insulating material on the electronic relay contacts that indicate that the brakes are disengaged. To help ensure successful future drives, engineers decided to permanently ignore the "brake-disengaged" indicator. If their theory is correct, the brake will actually be disengaged despite the "failure-to-disengage" indication. If they are wrong, a fuse in the brake circuit will safely blow when they attempt to move the steering actuators. In either case, driving operations will not be adversely affected.

A few sols ago, Spirit's engineering team discovered an electric-circuit grounding problem between the rover chassis and the power bus return. This incident occurred at the exact time the Spirit team was performing an inspection of the instrument deployment device, or robotic arm. The inspection sequence commanded one of the arm joints to a position beyond where it had previously been. That particular joint, joint number 5, is the rover arm turret, which rotates the four rover arm instruments into position. This coincidence may indicate that the joint 5 move somehow created the electrical short; it could also just be coincidence. The mechanical team has not found any reason to suspect a failure in the joint 5 cabling. To be safe, the engineering team has constrained the use of joint 5 on Spirit and Opportunity to avoid this extreme position. The constraint is not expected to significantly impact normal operations. The apparent short may also be the result of a failed measurement circuit. The short, if real, has no immediate effect on the rover, but does remove one layer of protection against effects of future shorts should they occur.

Between sols 292 and 298, Spirit completed its studies of the rock called "Uchben" and drove west about 2 meters (almost 7 feet) to a rock called "Lutefisk."

Between sols 299-303, Spirit finished its investigation of Lutefisk. Lutefisk, a rock with some interesting nodules, lies a site roughly 40 meters (131 feet) above and 2700 meters (1.67 miles) away from Spirit's landing site on the Gusev plain. Team members should know more about the chemistry of Lutefisk and its nodules when they receive results from the alpha particle X-ray spectrometer and Mössbauer spectrometer.

For coming sols, Spirit is in an exploration and discovery mode, continuing the rover's ascent towards "Machu Picchu" in the Columbia Hills. Spirit will stop at interesting rocks along the way.


sol 285-291, November 03, 2004: The engineering team is keeping Spirit moving

Spirit employed its full instrument suite on Sols 285 through 291 to study "Uchben," an interesting rock encountered on the way into the Colombia Hills. The engineering team continued to diagnose and study work-arounds for a problem with the steering brake relay. An anomaly related to electric-circuit grounding came to light during this period and is also being studied by the engineering team. Neither problem has hampered Spirit's daily operations. Spirit is otherwise healthy and ready to continue its trek further into the Columbia Hills.

The engineering team has been studying recovery options for steering brakes that apparently failed to release on two previous sols. On Spirit and Opportunity, dynamic braking is accomplished using a relay switch to place a short across the motor windings of an actuator that is not being used. If that actuator starts to move unexpectedly, the motor acts as a generator and the short provides an electrical load that slows the motor down. The same principle is used to generate electrical energy for hybrid cars when the brakes are applied. Thanks to forethought on the part of the rover design team, it is possible to disable the dynamic braking function using ground commands. Those commands deliberately and safely blow a fuse that is in line with the brake relay circuit. The absence of the braking function for the steering actuators in question (right front and left rear steering) will not affect the accuracy of our drives or the rover's safety when we are stopped. Until this problem is fully resolved, we will continue to drive with the right front and left rear steering actuators disabled, using tank-like steering.

Regarding the grounding anomaly, the engineering team regularly receives telemetry that tells them the voltage difference between "rover chassis" and "power bus return". The rover chassis is the conductive structure of the rover akin to an automobile chassis. The power bus return is a collection of wires designed to carry current back to the rover power source (battery or solar array). Ideally, all rover current flows in a loop from the battery or solar array, returning by way of the power bus return wires. No current is supposed to flow in the rover chassis though, in reality, some leakage paths exist that allow current to return by way of the rover chassis. When these currents flow across the circuitry that separates the rover chassis and power bus return, they create a small voltage that is measured and reported in telemetry. Until sol 287, the reported voltage was typically in the range of 0.6 to 0.8 volts. On Sol 287, that voltage dropped to 0 volts. The 0 volt reading could indicate that there is a problem with the measurement circuit, or it could indicate that power bus return and rover chassis are now shorted (making direct contact). The rover can operate when the chassis and power bus return are shorted together or when they are separated from each other by electrical circuitry. In the shorted case, however, the rover is more susceptible to permanent damage if another short occurs somewhere else. Engineers are looking at when the short indication occurred for clues about its possible root cause.

Sol specifics:

On 285, Spirit continued systematic atmospheric observations on this and all sols during this period using the miniature thermal emission spectrometer and panoramic camera. The rock abrasion tool was employed to drill a shallow hole at "Koolik," a location on the rock Uchben.

On sol 286, Spirit took microscopic images of the Koolik rock abrasion tool hole and placed the alpha particle X-ray spectrometer on Koolik for an overnight observation. The alpha particle X-ray spectrometer works best when cold.

During sols 287 through 289, Spirit placed the Mössbauer spectrometer on the Koolik rock abrasion tool hole for several observations over the Earth weekend. The Mössbauer spectrometer radiation source has weakened significantly since landing, through normal decay, so longer integration times are now required to get acceptable data.

On sol 290, Spirit performed tests to diagnose the root cause of the indication that steering brakes had failed to release, but the tests were inconclusive. Spirit then used the rock abrasion tool to brush "Chiikbes," another location on Uchben. Spirit placed the alpha particle X-ray spectrometer on Chiikbes for an overnight observation.

On sol 291, which ended on Oct. 28, Spirit took microscopic images of the Chiikbes brush site, and then placed the Mössbauer spectrometer on Koolik to improve the data from that location.


sol 279-284, October 25, 2004: Spirit's been mulling over 'Uchben'

Spirit is healthy and currently investigating a layered rock called "Uchben." Spirit is farther from the equator than its twin, Opportunity is, and it has much less available solar energy. Spirit's solar panels are pointed to the northern Sun, but Spirit is still only getting about 400 watt-hours of energy per day - enough to run a 100-watt bulb for four hours. Opportunity has been getting more than 700 watt-hours a day. The lower power supply for Spirit limits the rover's daily activities.

On sol 279, Spirit was parked at the location where a second occurrence of a problem with the rover's dynamic brake relay anomaly had halted a planned drive on sol 277. Scientists took the opportunity to analyze disturbed soil in front of the rover. Spirit deployed its robotic arm, acquired images of the soil with the microscopic imager, and placed the alpha particle X-ray spectrometer on a new target, named "TakeABreak," for an overnight integration.

Sols 280, 281, and 282 were built as a single three-sol plan to execute over Earth's weekend. On sol 280, Spirit acquired morning observations of sky and ground with its miniature thermal emission spectrometer, took a panoramic camera image to assess atmospheric quality, and completed the overnight alpha particle X-ray spectrometer measurement. After a midday nap, Spirit did a tool change from the alpha particle X-ray spectrometer to the Mössbauer spectrometer and began an overnight integration on the same soil patch.

On sol 281, Spirit completed the Mössbauer spectrometer measurement, took a midday nap, acquired three images of a nearby target called "Coffee" with the microscopic imager, and stowed the robotic arm. Spirit then successfully drove about 4 meters (13 feet) backwards, putting the target "Uchben" into the workspace of the robotic arm. The drive included straightening the right front and left rear steering wheels, which are the two impacted by a problem with the relay that is used in turning the steering motors on and off. The drive also successfully tested driving without use of the right front and left rear steering wheels to limit use of these motors while investigation of the malfunction continues.

On sol 282, Spirit acquired measurements of the sky and ground in the morning with the miniature thermal emission spectrometer, took the usual midday nap, and then made remote-sensing observations in the afternoon, including some navigation camera images for use in planning of future driving.

On sol 283, after receiving its daily commands and acquiring a panoramic camera assessment of atmospheric quality and miniature thermal emission spectrometer measurements of the sky and ground, Spirit took a midday nap. In the afternoon, Spirit deployed the robotic arm and acquired 20 images of a target region called "Koolik" on Uchben with the microscopic imager. Spirit then deployed the alpha particle X-ray spectrometer for an overnight integration.

On sol 284, which ended on Oct. 25, Spirit completed the alpha particle X-ray spectrometer measurement and then did a tool change to the Mössbauer spectrometer for a nighttime integration on Koolik.


sol 272-278, October 20, 2004: Spirit investigating ancient rocks

Spirit had a productive week investigating the rock "Tetl." On sol 277, Spirit attempted a drive to the next rock target, "Uchben," which means "ancient" in the old Mayan language. Halfway into that drive, Spirit experienced a repeat problem in the steering motor control system that engineers first saw on sol 265. Engineers repeated diagnostic tests for the problem on sol 278. Those tests showed that the electronics relay in question is still functional, but appears to operate intermittently. Spirit is otherwise healthy and is in a safe location.

On sol 272, Spirit took images with the microscopic imager to create a mosaic of Tetl's layered rock face.

On sol 273, Spirit captured more microscopic images of Tetl's layered face, then put the alpha particle X-ray spectrometer in place for an early morning observation.

On sol 274, Spirit woke up at 4:00 a.m. to start the alpha particle X-ray spectrometer observation. The alpha particle X-ray spectrometer stayed on until the start of normal morning atmospheric science observations. Spirit also used its miniature thermal emission spectrometer to observe nearby rocks named "Zackuk" and "Palenque," which are possible future targets for in-depth observations. Later, Spirit changed tools on its robotic arm, placing the Mössbauer instrument on Tetl for an observation the next morning.

On sol 275, Spirit completed a 6-hour Mössbauer integration and performed daily atmospheric observations. This was the final sol of Spirit's weekend plan and was purposely simple to enable the sequencing team to complete a 3-day plan on Friday.

On sol 276, Spirit restarted the Mössbauer instrument at 4:00 a.m. for another 10 hours of integration time on the same spot. Spirit also took a few final microscopic images of Tetl, then stowed the robotic arm in preparation for the next sol's drive.

On sols 277 and 278, Spirit attempted a drive to Uchben, another layered rock roughly 6 meters (20 feet) northeast of Tetl. About 2.5 meters (8 feet) into the drive, the mobility software attempted to move a steering motor by first commanding open a relay (electronic switch) that releases a dynamic brake. The feedback from that command indicated that the relay was still closed, so the motor control software declared an error. Due to the error, the rover ignored that steering command and all subsequent driving commands. The root cause of the failed relay command is under investigation. A diagnostic test last run on sol 270 was repeated on sol 278, which ended on Oct. 14. That test showed that the steering motor's dynamic brake relay can still be opened and closed, but does occasionally (5 out of 10 times) indicate that it is still closed after being commanded open.

More diagnostics tests are needed before the source of the problem can be positively identified. Until then, engineers will continue to drive, but will steer the rover in a tank-like fashion, not using the steering actuator in question.

Future plans are to clear the drive error and attempt another drive to Uchben on sol 281. Engineers are also planning to run more diagnostic tests starting on sol 282.


sol 263-271, October 11, 2004: Spirit investigating 'Tetl'

After working on Mars for three times as long as its primary three-month mission, Spirit is healthy and currently investigating the rock called "Tetl" in the "Columbia Hills." In the language of the ancient Mayans, tetl means stone.

On sol 263, Spirit successfully drove approximately 7 meters (23 feet) and acquired images to build a digital elevation map of the hills. This put Spirit on the south side of a 2-meter-diameter (7-foot-diameter) depression, with Tetl on the opposite side.

On sol 264, Spirit drove about 4 meters (13 feet) around the edge of the depression to keep the rover's solar panels (which are the rover's main power source) tilted toward the Sun. Since the Sun moves low across the northern sky over Gusev Crater at this time of year, rover planners are attempting to keep the solar panels tilted toward the north. The drive included use of the five-wheel mode to minimize use of the sticky right front wheel, which inefficiently pulls too much power when it is activated. Spirit also gathered additional about potential science targets, using the miniature thermal emission spectrometer and panoramic camera at the end of the rover's robotic arm.

On sol 265, Spirit attempted to approach Tetl, but the drive ended early because the flight software detected that a steering brake control function did not work. Remote sensing data was still acquired.

On sol 266, with an ongoing investigation of the steering anomaly, no further driving was planned. Several targets in front of the rover were selected for the alpha particle X-ray spectrometer and Mössbauer spectrometer. Spirit completed alpha particle X-ray spectrometer readings on two different locations.

On sol 267, Spirit successfully acquired remote sensing data and moved its robotic arm to put the alpha particle X-ray spectrometer at a third position during the day and a fourth position overnight.

On sol 268, Spirit acquired additional remote sensing data and performed a tool change to the Mössbauer spectrometer, then started an overnight integration with that instrument.

On sol 269, Spirit continued the Mössbauer spectrometer integration and performed a diagnostic test on the steering brake. The test indicated that there was no problem with the commanding process at that time.

On sol 270, Spirit acquired remote sensing data, stowed its arm, and ran another steering diagnostic test. The cause of the steering brake issue has not been identified, but tests indicate that electronics related to the brake function and the overall steering capabilities of Spirit are healthy. Engineers are proceeding with normal operations, including mobility.

On sol 271, which ended on Oct. 7, Pacific Time, Spirit successfully drove approximately 2 meters (6.6 feet). This put Tetl within reach of the robotic arm. After the drive, Spirit used its navigation camera to view the scene from the rover's new location.

Spirit has driven a total of 3,641 meters (about 2.3 miles) since landing nine months ago.

Future plans for Spirit include more intense investigations of Tetl and a 20-meter (66-foot) drive to a target called "Machu Picchu."


sol 243-262, September 29, 2004: Spirit back to normal operations

Spirit has successfully transitioned back to normal operations from conjunction operations, when Mars and Earth were on opposite sides of the Sun. During conjunction (sols 244 through 255), engineers and scientists did not attempt normal operations due to the low probability of successful communications. From sols 244 to 249, the rover team did transmit several "no operation" commands to test the communications link. On Spirit's sol 249, Opportunity experienced an unexpected software reset, apparently triggered by a corrupted "no operation" command. As a result of that problem, engineers ceased all commanding on Spirit from sol 250 until sol 256, at which time the likelihood of receiving corrupted commands was once again very low.

From sols 244 through 255, pre-loaded sequences performed daily science, which included atmospheric studies (using the miniature thermal emission spectrometer and the panoramic camera) and Mössbauer spectrometer integration on the filter magnet, which is one of two dust-collecting magnets on Spirit's main deck. Spirit relayed data to the Mars Odyssey orbiter every afternoon throughout conjunction. Odyssey in turn attempted to relay that data back to Earth with limited success due to solar conjunction. As a result of the difficulties getting data off of the rover, the memory available for science data storage shrunk to roughly 100 megabits by sol 261, but has recovered as of sol 262 to roughly 400 megabits.

Sol highlights:

Sol 243 was the last sol of normal commanding for Spirit before conjunction. The rover team successfully re-transmitted four conjunction sequences that had not made it on-board during the sol 242 uplink. The team saw no transmission errors (but commanded everything twice just in case), and the rovers performed the commanded remote sensing science.

On sol 244, the rover team transitioned into conjunction operations and did the first "no-op" commanding tests during midday to see how effective the command link was as Mars moved further behind the Sun. The team received data from the Odyssey orbiter indicating that Spirit was healthy and proceeding normally with on-board conjunction sequences.

Sols 245 through 255 were the solar conjunction quiet period. No commanding was done. Spirit automatically took daily atmospheric science measurements and made filter magnet observations with the Mössbauer spectrometer.

During sols 256 through 257, Spirit took 48 more hours of Mössbauer observations on the filter magnet. A dirt clod from a previous Mössbauer soil touch was inadvertently placed on the perimeter of the filter magnet on sol 240. As a result, engineers believed this could have been the rover team's last best chance to collect Mössbauer data on the uncontaminated dust sample from that magnet. This is because when the Mössbauer instrument was removed, there was a chance that dirt from the clod would sprinkle or spread to the center area of the magnet.

On sol 258, the team removed the Mössbauer instrument from the filter magnet and took microscopic images of the both magnets. From the image thumbnails, the team could see that some dirt from the clod was indeed deposited on the outer area of the filter magnet. Front hazard-avoidance camera images taken after the Mössbauer spectrometer was removed clearly showed dirt still attached to the Mössbauer contact plate.

After finishing with the magnets, engineers moved the rover arm back down to the soil, to the same spot that had been touched by the Mössbauer instrument on sol 240. The rover team then repeated a microscopic imager sequence of that soil to see if winds had deposited anything there during conjunction. The team then centered the alpha particle X-ray spectrometer on the same soil and started an integration later that night.

On sol 259, Spirit changed tools to the Mössbauer spectrometer and started a 24-hour integration on the same disturbed soil spot. Spirit also started a three-sol thermal investigation, using panoramic camera and miniature thermal emission spectrometer observations of soil targets several times during each sol.

On sol 260, Spirit completed the Mössbauer integration of the disturbed soil.

On sol 261, Spirit stowed its arm then drove backwards 1.5 meters (4.9 feet) to take post-conjunction panoramic camera pictures of the soil underneath the rover as part of the conjunction wind experiment. Spirit also took navigation camera images of the road ahead in preparation for future drives.

On sol 262, due to the limited amount of available science data storage, planned activities were limited to a Mössbauer spectrometer integration on a rock, limited remote sensing, and routine atmospheric observations. That plan did not make it on board due to a problem during the communications uplink session. The deep space network antenna was pointed a few degrees below its lower safety limit when the transmitter was supposed to turn on, causing an interlock mechanism to turn off the transmitter. By the time the antenna was reconfigured, not enough time remained to get the full sequence load transmitted. Fortunately, one sequence did make it to the rover and was successfully executed, freeing up roughly 250 megabits of memory for future sols. Sol 262 ended on Sept. 28.


sol 239-242, September 09, 2004: Spirit on Autopilot

Spirit is in safe place to continue daily science observations automatically throughout the solar conjunction period when engineers and scientists will be unable to send commands reliably to the rover. An 18-day period began a transition into solar conjunction on sol 241, when the Sun partially obscured the communications path between Earth and Mars, making communications sessions unreliable. Engineers were able to successfully command Spirit on sol 241, and they had partial commanding success on sol 242.

Engineers will attempt to command Spirit on sol 243 also. From sol 244 through sol 255, sequences already safely on board will perform a set of science activities on a daily basis. On sols 256 through 258, the last three days of conjunction, the rover team will attempt normal operations again.

On sol 242, engineers sent Spirit a set of coordinated commands to use the miniature thermal emission spectrometer and panoramic camera for observations of possible future science targets. A new set of 12 conjunction master sequences was also transmitted successfully to Spirit. This new set of conjunction master sequences will use less energy than previous sequences.

For the conjunction period, the rover team has placed the Mössbauer spectrometer on one of the two magnets on the rover deck. Spirit will activate the Mössbauer instrument every day during conjunction in order to characterize the dust that has collected on the magnet. However, a wrinkle has developed in this plan. Before placing the Mössbauer spectrometer on the magnet, Spirit placed it on the soil in front of its current location. That soil touch was done to leave a soil impression that would be studied after conjunction for changes. Images taken after the touch indicate that Spirit inadvertently picked up some soil and likely sandwiched that soil onto the magnet with the Mössbauer. It's the team's first inadvertent sample acquisition!

Engineers and scientists decided to leave the Mössbauer in place on the magnet and will evaluate the status and effect of the dirt clod after conjunction. The dirt does not pose any threat to the rover from an engineering perspective.

Since Spirit arrived at its solar-conjunction resting place, its science activities have focused on gathering data from the surrounding area for use in planning post-conjunction sols. Navigation camera images in Spirit's drive direction have been used to develop traverse maps. These maps show areas that allow Spirit to maintain a north-facing tilt; these areas will provide significantly more solar energy and will therefore be favored as the team plans the traverse to Spirit's next science target.

During conjunction, Spirit will transmit five-minute "beep" tones, and engineers will send "No-operation" commands to the rover to characterize effects that the conjunction has on radio transmissions between Mars and Earth.


sol 232-238, September 07, 2004: Spirit finishes observing 'Ebenezer' and moves on to 'Tikal'

Spirit found a comfortable location on a rock outcrop and spent cold autumn days performing observations of a rock called "Ebenezer" with the rover's science instruments. Spirit finished observations of Ebenezer and moved over to the next location, "Tikal," about nine meters (30 feet) away. Spirit will spend solar conjunction at Tikal. Solar conjunction is when Earth and Mars are on opposite sides of the Sun. Due the interference with the Sun, communications between Earth and the spacecraft at Mars will be minimal during solar conjunction, which occurs during Spirit's sols 244 through 255.

On sol 232, Spirit completed an overnight reading with its alpha particle X-ray spectrometer on a target dubbed "Cratchit 2," where the rover had earlier used its rock abraision tool to cut a hole exposing the rock's interior. Spirit took images of the same target with the microscopic imager. Spirit then placed the Mössbauer spectrometer on Cratchit 2 and started a very long, two-sol integration.

After the two-sol Mössbauer spectrometer activity, Spirit spent sol 234 performing 90 minutes of remote sensing. On sol 235, Spirit changed tools from the Mössbauer spectrometer to the microscopic imager and took pictures. Then Spirit used the alpha particle X-ray spectrometer for thirty minutes. After completing the alpha particle X-ray spectrometer reading, the arm was stowed so that on sol 236 the rock abrasion tool brushings could be imaged using the panoramic camera without the arm blocking any part of the image.

Spirit spent sols 236 to 238 brushing eight adjoining patches on Ebenezer to create a large enough scrubbed area for analyzing with the miniature thermal emission spectrometer, then drove up to the rover's designated vacation spot for solar conjunction.

Spirit bumped backwards on sol 237, and took some navigation camera images of the brushed area of Ebenezer to support miniature thermal emission spectrometer observations on the next sol. A navigation camera panorama was taken in the expected drive direction, toward Tikal.

In the morning of sol 238, the panoramic camera imaged the brushed area of Ebenezer. A little after noon, the miniature thermal emission spectrometer took spectral readings of both the brushed area and a hole that rock abrasion tool hole had cut into Ebenezer on sol 231. At 2 p.m. Gusev time, Spirit took an afternoon drive to Tikal, about nine meters (30 feet) away.


sol 219-231, August 31, 2004: Spirit has been etching into 'Ebenezer'

During sols 219 through 223, Spirit completed science observations at the "Clovis" rock outcrop. So Spirit packed up and slowly moved on. Winter is approaching and temperatures continue to drop. Power is always a major concern as available energy fluctuates between 300 and 400 watt-hours per sol, but Spirit continues the quest, climbing ever higher into the Columbia Hills. Spirit has climbed more than 13 meters (43 feet) in elevation from Hank's Hollow, at the base of Columbia Hills, but currently is at an elevation of 37 meters (121 feet) above its landing site on the plains of Gusev Crater!

On sol 224, operators became concerned that Spirit's batteries might be entering a very low state of charge, so Spirit shut down to charge the batteries.

Sol 225 was truly a mega-activity sol. Spirit awoke at 11:20 a.m., Gusev local solar time and stayed awake well past the afternoon communication session with NASA's Mars Odyssey orbiter without taking a nap. Spirit hasn't done that in a long time. The rover extended its arm and used its rock abrasion tool to brush seven circular patches on Clovis. After the first five brushings, the arm was moved out of the way and an image was taken of the circles. These five brushing circles resemble the Olympic rings.

After completing the brushing, Spirit performed a 30-minute reading with its alpha particle X-ray spectrometer, imaged the seven rings using its microscopic imager, stowed its arm and drove one meter (three feet) backward, farther off of the Clovis outcrop. Spirit's day was far from over. The rover performed post-drive observations with its navigation camera, observations with its miniature thermal emission spectrometer concurrent with the afternoon Odyssey pass, and panoramic camera observations before shutting down. Another gold medal performance for Spirit!

Total odometry after sol 225 was 3,605 meters (2.24 miles), a Mars record.

From sols 226-229, Spirit stopped at a rock dubbed "Ebenezer" for several sols of intense science. Ebenezer is roughly 8 meters (26 feet) from Clovis.

While at Ebenezer, Spirit was facing south of east, with its nose pitched up 21 degrees. This orientation was very favorable from a power perspective since the sun tracks to the north. Spirit's daily solar energy input increased about 10 percent as a result. Spirit also had a great view of the Gusev plain from this location.

On Sol 230, Spirit used the rock abrasion tool to brush a target on Ebenezer and took an overnight alpha particle X-ray spectrometer reading on the brushed area. On Sol 231, which ended on Aug. 27, the abrasion tool ground for two hours into the same spot it had brushed. An alpha particle X-ray spectrometer reading in the resulting hole began the morning of Sol 232.

Over the next few sols, the plan is for Spirit to drive to its next target, which is yet to be determined.


sol 209-218, August 23, 2004: Spirit probes deeper into 'Clovis' outcrop

Spirit continued work over the past nine sols at a rock called "Clovis." The rover used its rock abrasion tool, microscopic imager, alpha particle X-ray spectrometer, and Mössbauer spectrometer to probe deeper into the history of this rock. Clovis is the most altered rock encountered by Spirit to date. It is part of a rock outcrop located on the "West Spur" of the "Columbia Hills," roughly 55 meters (180 feet) higher than Spirit's landing site about 3 kilometers (2 miles) away.

Spirit also successfully performed a couple of communications tests with the European Space Agency's Mars Express orbiter last week. The tests demonstrated the two spacecraft's ability to work together to transmit data collected by the rovers to Earth via the Mars Express communications relay. NASA's Mars Odyssey and Mars Global Surveyor orbiters also have this capability. More than 85 percent of the data from the rovers has been transmitted to Earth via the Odyssey orbiter.

On sol 209, Spirit experienced an unexpected reboot of the flight software. This incident was not a threat to the spacecraft. It is a known bug in the system that the rover team is working around.

On sol 210, Spirit drove up steep terrain to reach the exact spot on Clovis for work with the science instruments at the end of the robotic arm.

Between sols 211 and 216, Spirit completed an alpha particle X-ray spectrometer reading of a spot on Clovis called "Plano," which had been brushed off using the rock abrasion tool. Spirit then placed the rock abrasion tool on Plano again and drilled for 2.5 hours, creating a hole 8.9 millimeters (0.4 inch) deep, which is a new record! Spirit also continued a campaign to capture a color 360-degree panoramic camera image from this location. Spirit captured additional segments of the panorama on sols 217 and 218.

On sol 217, Spirit took microscopic images of the rock abrasion tool hole, and then placed the alpha particle X-ray spectrometer in the hole for an early morning observation.

On sol 218, Spirit placed the Mössbauer spectrometer in the rock abrasion tool hole and started a 48-hour observation. This is a longer than normal integration time, with a goal of resolving in more detail the makeup of this highly altered rock.

Spirit remains in excellent health.


sol 205-208, August 11, 2004: Spirit is investigating 'Clovis' outcrop

Over the last few sols, Spirit struggled mightily to reach a rock outcrop called "Clovis," overcoming the challenge of rough, steep terrain and subsequent backsliding. The site is near the crest of the "West Spur" of "Columbia Hills."

On sol 205, Spirit attempted to reach Clovis by climbing out of the sandy hollow in which it was sitting. Unfortunately, on a slope of more than 20 degrees, slippage caused Spirit to dance around the outcrop. The drive was finally cut off by a time-of-day limit on rover mobility.

The plan for sol 206 was designed to accommodate up to a 50 percent slip and still reach the outcrop target. However, due to challenging terrain near Clovis, Spirit again did not end up exactly where scientists and engineers wanted it to go. For part of its traverse, Spirit slipped about 125 percent, actually losing ground in its attempt to move uphill.

Late in the sol, internal software experienced a timing problem in which two instrument-related commands were given at nearly the same time, temporarily precluding further operation of the miniature thermal emission spectrometer and camera mast on Spirit.

Sol 207 became a recovery sol. While the timing issue was being analyzed, engineers decided not to use the mast, panoramic cameras, navigation cameras, Mössbauer spectrometer, alpha particle X-ray spectrometer, or the miniature thermal emission spectrometer. On the bright side, since the problem did not affect communications, a communications experiment with the European Space Agency's Mars Express orbiter was successfully conducted in the early morning hours of sol 208.

By sol 208, which ended on Aug. 3, Pacific Time, the mast had been declared usable. Operators commanded Spirit to drive 7.5 meters (25.6 feet) to Clovis, using a route avoiding the steepest terrain that had created problems for the rover in earlier sols.

Spirit is examining Clovis. This outcrop will likely be the subject of Spirit's most intensive investigation to date.


sol 201-204, August 03, 2004: The quest for the top of the hills continues

Mars has seasons like the Earth does, but the seasons are twice as long due to Mars' larger orbit around the Sun. Right now, Mars is approaching northern summer. That also means that it's approaching southern martian winter at the same time. So Spirit is headed for winter, being 14 degrees south of the equator. Because martian winter is setting in, solar array energy continues to be a concern for Spirit. If Spirit parks with a northerly tilt, the rover will see between 350 and 380 watt-hours of energy, but if Spirit stops on flat ground or with a southerly tilt, solar energy is as low as 280 watt-hours. So engineers make a concerted effort to find the north-facing islands along Spirit's path.

On Sol 201, Spirit was commanded to drive 98 feet (30 meters) across terrain that was pretty steep. Spirit accomplished 8.2 feet (2.5 meters) then stopped due to an excessive tilt angle of 25.6 degrees. Engineers had set the maximum tilt angle limit at 25 degrees. Spirit did complete pre-drive science observations and post-drive imaging.

On sol 202, Spirit repeated the drive plan from sol 201 with the maximum tilt angle set to 32 degrees. This time the rover completed the drive as planned, traveling 83.6 feet (25.5) meters up the hill. Spirit then performed post-drive imaging.

On sol 203, scientists' hope was to find rock outcropping in this location, but none were found. So the decision was made to continue the drive up the hill to find a better rock outcrop. Spirit performed another six-wheel, 62-foot (19-meter) drive. This drive was completed successfully; however, at the end of the drive, Spirit drove into a small hollow. As a result, Spirit was pitched 15 degrees toward the southwest, and ended up with a southerly tilt.

Planning for sol 204 was very exciting due to the late downlink of information from sol 203. Very late in the planning cycle, available power on sol 204 was reduced from 370 watt-hours to 288 watt-hours. Ouch! Pre-drive observations were cut back to 17 minutes, during which the motors were heated for driving. Spirit drove only 0.82 feet (0.25 meters). Because the drive was so short, the power situation is not as bad as it could have been.

Total odometry after sol 204, which ended on July 30, is 2.21 miles (3,565.57 meters). Total elevation above the plains of Gusev Crater is estimated to be 30 feet (9 meters).

Over the next few sols, scientists and engineers hope to make it to "Clovis" rock outcrop and to recharge the batteries.


sol 198-200, July 28, 2004: Spirit Survives 200 Sols!

On sol 198, Spirit completed a long overnight reading by the Mössbauer spectrometer on a rock target called "Sabre," then ground a second rock abrasion tool hole on a target called "Mastodon." The alpha particle X-ray spectrometer was placed in the fresh hole in preparation for a reading, which was started during the overnight Odyssey communication pass.

On sol 199, Spirit completed a 6-hour early morning alpha particle X-ray spectrometer reading on Mastodon. After a midday nap to conserve energy, Spirit took pictures with the microscopic imager to create a mosaic of the rock abrasion tool hole. Spirit then placed the Mössbauer instrument in the hole and began a 20-hour overnight reading.

Sol 200, ending on July 26, was a busy day for Spirit. Spirit completed the overnight Mössbauer reading on the rock abrasion tool hole, took a midday nap, stowed the arm, bumped back to take pictures and readings of the hole with the panoramic camera and miniature thermal emission spectrometer, then drove about 52 feet (16 meters). Due to the nature of the terrain, the drive was done in 6-wheel mode to minimize errors (rather than the current standard 5-wheel mode to conserve the aging right front wheel). Engineers carefully targeted Spirit's drive to end in a location with favorable tilt to the north to point the solar panels toward the Sun, giving Spirit as much power as possible as the Sun hangs low in the sky during martian winter.

Spirit will continue to drive up the Columbia Hills and search for more rock outcroppings.


sol 194-197, July 26, 2004: Spirit Investigates "Wooly Patch"

On sol 194, Spirit took a large microscopic imager mosaic, consisting of 34 images at multiple positions, of a target called "Sabre" on an outcrop rock called "Wooly Patch." This was followed by a two-hour reading by the Mössbauer spectrometer and an overnight, seven-hour reading by the alpha particle X-ray spectrometer.

On sol 195, the rock abrasion tool dug a surprisingly deep hole in only two hours of grinding. The rock appears to be softer than what scientists and engineers have seen previously in Gusev Crater. The alpha particle X-ray spectrometer was placed in the rock abrasion tool hole at Sabre. However, due to uncertainties in how long the arm and grinding operations take, the sequence was terminated a few minutes too early and a planned overnight alpha particle X-ray spectrometer integration did not take place.

Spirit recovered the alpha particle X-ray spectrometer integration in the sol 196 plan. The sol began with a microscopic imager mosaic of the rock abrasion tool hole. The alpha particle X-ray spectrometer was put back in position in the hole, and reading lasting more than six hours was successfully performed, starting at about 4 a.m. Gusev time on sol 197.

The work on Sabre was completed with a very long, 21-hour Mössbauer integration, which was expected to be completed the morning of sol 198 (July 24). Before the integration was started on sol 197, a microscopic imager mosaic was taken of "Mammoth," the next rock abrasion tool target on Wooly Patch.


sol 190-193, July 26, 2004: Spirit is Driving Backwards on Five Wheels

On Sol 190, Spirit completed remote sensing and a 13-meter (43-foot) drive, which included driving on 5 wheels to minimize further degradation of the actuator on the sixth, aging, right front wheel. During the 5-wheel portion of drive, visual odometry was used to accurately estimate the rover position. The drive ended with a short 6-wheel drive to achieve the desired position. This approach worked well, and engineers will continue to do 5-wheel driving to preserve the right front wheel actuator life while still achieving the desired position.

On Sol 191, Spirit took pictures with the microscopic imager and used the Mössbauer spectrometer on soil, then successfully completed another 10-meter (33-foot), 5-wheel drive to the north. (As Spirit is driving backwards to 'drag' the right front wheel, the robotic arm is effectively now in the back of the rover.)

On Sol 192, Spirit turned east off of a planned northerly traverse route to investigate a potential rock outcropping. The 17-meter (56-foot) drive, which included two sections of 5-wheel driving, landed Spirit right on top of the outcrop. Unfortunately, the drive left the rover at a bad tilt angle for solar energy, decreasing the available energy.

On Sol 193, which ended on July 19, Spirit completed a series of microscopic images and a short Mössbauer reading on the outcrop. Spirit then moved into a better position to use the rock abrasion tool and to improve the tilt toward the Sun for solar energy.

In the upcoming sols, Spirit will use the rock abrasion tool and other science instruments to investigate Wooly-Patch. Then it will resume driving up the "Columbia Hills" to look for more outcrops.


sol 184-189, July 26, 2004: Spirit Completes its 'Tune-up' and Begins Driving Backwards

On sols 184 and 185, Spirit cycled heaters and attempted to lubricate the right front wheel's drive motor. Spirit also performed very short test drives. Spirit's orientation on "Engineering Flats" had the rover in a slight southerly tilt, away from the Sun. This low Sun angle, coupled with the power required to energize the heaters, put quite a strain on the batteries. The state of charge of the batteries after the test was very low, so science observations were not performed during these two sols.

On sol 186, Spirit used its instrument deployment device, or robotic arm, to validate a new front hazard-avoidance camera model. This new model will improve the positioning accuracy of the tools on the arm. The arm attempted to place the Mössbauer spectrometer at nine different locations. Seven targets were hit, and two targets were missed. The engineering team planned to repeat this operation on the two missed positions on a later sol. Spirit also performed a test drive to characterize the results of the lubrication activity. The beginning orientation of the vehicle had the right front wheel facing the Sun, so the starting temperature was much warmer than the original baseline test drive. This temperature difference makes it hard to accurately compare the pre and post test-drive results. Analysis indicates there is approximately a 20 percent increase in wheel drive performance, but engineers cannot attribute this gain to the four-sol wheel heating operation alone. Spirit sat mostly motionless for the about the last 30 sols, and that allowed some lubrication to re-flow naturally. The bottom line is that the right-front wheel's performance has improved, but it is still drawing about twice as much current as any other wheel.

After the tune-up, Spirit was free to begin its drive away from Engineering Flats and head to higher ground and a better solar orientation. On sol 187, with its batteries very low, Spirit limped 8 meters (26 feet) to a location with a slightly better tilt toward the Sun and performed about 50 minutes of science observations.

On sol 188, Spirit continued to drive away from Engineering Flats. As a strategy for dealing with the right-front wheel, Spirit is now driving backwards and dragging its right front wheel when it is on relatively flat terrain. This strategy aims to extend the lifetime of the wheel's drive motor for use when it is needed most. Spirit performed its first backward test drive of 4 meters (13 feet) on this sol. Spirit also performed about an hour and a half of remote-sensing observations using the panoramic camera, navigation camera and miniature thermal emission spectrometer.

On sol 189, which ended on July 15, Spirit's battery state of charge increased due to a better tilt of the solar arrays toward the Sun. Spirit performed a precision 6-meter (20-foot), 6-wheel drive, then drove another 3 meters (10 feet) doing the wheel drag. Spirit also imaged an interesting rock outcrop. The outcrop was directly beneath the vehicle and extending northward.

Total odometry after sol 189 is 3,450 meters (2.14 miles). Vehicle heading is 184.8 degrees.


sol 181-182, July 16, 2004: Spirit Gets Into Position for a Tune-Up

Sol 181:
On sol 181 the plan for Spirit was to deploy the instrument deployment device for microscopic imaging, then perform a two-hour Mössbauer integration. The rover was to conduct miniature thermal emission spectrometer and navigation camera observations of rover-disturbed soil. After this, the rover was to drive to a relatively flat area dubbed "Engineering Flats." This was to prepare for a multi-sol engineering activity to heat, and ideally re-lubricate, the right-front wheel actuator. After the drive, Spirit was to take a 360-degree navigation camera panorama, followed by miniature thermal emission spectrometer observations during the communications session with NASA's Mars Odyssey orbiter. Unfortunately, as Spirit began to execute the sol 181 plan, the onboard software predicted an instrument deployment device collision. This prevented further arm functions and the drive.

Sol 182:
On Sol 182, rover planners quickly determined the cause of the instrument deployment device error and continued to plan for sol 182 as normal. The intent for sol 182 was to complete the activities originally intended for sol 181. The sol 182 plan executed nominally, placing Spirit squarely in the middle of Engineering Flats.


sol 179-180, July 15, 2004: Spirit Reaches 180 Sols!

On sol 179, Spirit woke up at a new location and spent the day performing remote sensing with the miniature thermal emission spectrometer, including an overnight observation.

Sol 180 marked a grand accomplishment for Spirit. The rover has survived two times the original planned mission duration of 90 sols. On this notable sol, the rover continued with remote sensing, performing miniature thermal emission spectrometer observations on disturbed soil and rover tracks. Spirit then looked at the targets "Cookie Cutter" and "Julienned" with the panoramic camera. Because of power and timing issues, Spirit was not able to complete intended microscopic imaging, Mössbauer spectrometer, and alpha particle X-ray spectrometer measurements at this site. These operations were moved into the sol 181 plan. Total odometry after sol 180 is 3414 meters (2.1 miles).


sol 175-178, July 09, 2004: Spirit Tries Out Visual Odometry

On sol 175, Spirit analyzed the new targets "Breadbox" and "Sourdough" with its panoramic camera and miniature thermal emission spectrometer. Spirit then got an up-close look at Breadbox with the microscopic imager, and deployed the Mössbauer spectrometer on Sourdough for an overnight integration. In the middle of the martian night, Spirit did a tool change to the alpha particle X-ray spectrometer and completed a five-hour integration before the sol 176 plan began.

Spirit spent sol 176 getting a battery re-charge and a front hazard avoidance camera calibration. The evening of sol 176, engineers commanded Spirit to wake up and enable the panoramic camera mast actuator heater so they could determine when the thermostat turns the heater on. The heater turned on when expected, which will allow Spirit to conduct a night-time miniature thermal emission spectrometer observation in a few sols.

On sol 177, Spirit successfully performed a series of observations on an interesting and shiny feature called "String of Pearls." The rover acquired two microscopic images of the target and an overnight integration with the Mössbauer spectrometer and alpha particle X-ray spectrometer. As Mars' southern winter approaches, Spirit's energy resources become increasingly limited. Overnight tool changes and their associated heating take a big toll on the limited energy budget, and require some preparation and recovery to keep up Spirit's battery charge.

Spirit began sol 178 by stowing the robotic arm and then backing up 1.5 meters (about 5 feet) from "Hank's Hollow" in order to properly place the miniature thermal emission spectrometer to get a good view of "Pot of Gold" and nearby rover tracks. Engineers also took this opportunity to use visual odometry for the first time on Spirit. This is a technique in which the rover takes successive images of its surroundings during a drive and then matches features in those images on-board to compute how far and in what direction it has moved. Both the drive and the test went well, and ground verification showed that the matching worked quite nicely with the features in this terrain. Visual odometry will be important if and when Spirit starts driving on five wheels, since the actual drives can and will be rather different than what is commanded. The rover can use the visual odometry estimates while driving to compensate for the slipping and yawing that engineers expect with five-wheel driving.


sol 171-174, July 02, 2004: Moving On From 'Pot-of-Gold'

On sol 171, Spirit continued its investigation in "Hank's Hollow" and the rock target "Pot-of-Gold." The rover successfully completed observations of the abraded area with the microscopic imager and alpha particle X-ray spectrometer.

On sol 172, Spirit looked at the sky with the miniature thermal emission spectrometer and panoramic camera. The rover also acquired some thermal inertia observations of nearby soil with the miniature thermal emission spectrometer. Spirit finished up its Pot-of-Gold observations with some microscopic images and a final long Mössbauer integration of the abraded surface.

On sol 173, Spirit performed atmospheric observations with the miniature thermal emission spectrometer and panoramic camera. The rover also took some panoramic camera context images for the sol 172 thermal inertia observations. The rover finished the day's work by stowing the instrument deployment device and doing a "bump-back" to the "Bread Box" target. One last panoramic camera shot of Pot-of-Gold ended up a bit overexposed and will need to be retaken.

On sol 174, Spirit began the day acquiring atmospheric observations with the mini thermal emission spectrometer and panoramic camera. The rover then imaged the drive direction with the panoramic camera. Last but not least, Spirit took a look at a disturbed area of soil called "Bright Tracks" with the panoramic camera to help scientists learn more about the very bright material found here.

During the next 15 or more sols, rover planners will perform a "3,000 meter tune-up" on Spirit before the rover embarks on a climb up the hills.

The tune-up will include a number of elements including:

A front hazard avoidance camera calibration where a series of robotic arm poses and hazard avoidance camera images will be used to refine the rover planners' ability to target objects using stereo hazard avoidance camera images. The team is currently experiencing a 2 to 3 centimeter (slightly less or slightly greater than an inch) error in predicted versus actual target locations in the vicinity of the instrument deployment device.

Spirit's first deep sleep. Deep sleep is a mode that leaves the rover completely un-powered overnight, saving the energy that would be spent powering rover electronics and survival heaters that are normally on even when the rover is napping. Spirit needs deep sleep to save energy in the coming sols. Since deep sleep is potentially harmful to the mini thermal emission spectrometer instrument because its survival heater is not powered, rover planners have identified two observations that must be completed before the first deep sleep is attempted. Opportunity has been using deep sleep for several weeks now.

A right front wheel lubrication. Spirit's right front wheel continues to draw roughly twice the current of the other wheels. Spirit will drive to "Engineering Flats," a relatively flat, hazard-free area where rover planners will execute a series of diagnostic drive tests and heating sequences over the course of four to five sols. The intent is that the heating will re-flow the lubricants in this actuator, correcting the problem. Engineering Flats is roughly 7 meters (nearly 23 feet) from Spirit's current location.

Engineering tests of visual odometry. Visual odometry uses navigation camera images taken during a drive to determine the rover's location. This rover feature has been improved and is ready for trial runs now. Rover planners would like to use it on a regular basis to get Spirit where they want it to go more quickly. Due to slippage, Spirit sometimes needs two or more sols to make a short approach when using the blind drive technique.


sol 167-170, June 30, 2004: Just a Little Rock Abrasion Tool

On sol 167, Spirit looked at a bit of soil called "Jaws" with the alpha particle X-ray spectrometer and microscopic imager. Then the rover completed a drive intended to put it into position to analyze "Pot-of-Gold" with the instruments on its robotic arm. The drive moved Spirit farther than expected though, and the rover ended up directly over the rock. That position prevented any observations with the instrument deployment device.

On sol 168, rover planners commanded Spirit to "bump" backward, into a position where the rock abrasion tool could make contact with Pot-of-Gold. This was successful, and Spirit spent the rest of the time taking images of the surrounding area with its panoramic and navigation cameras.

On sol 169, Spirit successfully operated its rock abrasion tool on Pot-of-Gold, grinding away the top .2 millimeters (.008 inches) of rock from the high points. The procedure took 1 hour and 45 minutes. Pot-of-Gold posed a special challenge to the rover team because it is quite small -- only slightly larger than the rock abrasion tool instrument itself. The rock abrasion tool inflicts about 6.8 kilograms (15 pounds) of pressure on its rock targets, and smaller rocks aren't necessarily stable enough to resist this.

Before and after pictures of Pot-of-Gold showed that the rock was moved by the rock abrasion tool procedure. That movement, plus possible slippage where the tool contacts the rock, resulted in only intermittent contact during the grinding operation. After the grind was complete, Spirit placed the alpha particle X-ray spectrometer on the freshly exposed area in preparation for an operation later that night.

On Sol 170, Spirit awoke to stop the alpha particle X-ray integration, took miniature thermal emission spectrometer and panoramic camera images of some local track marks, took more microscopic images of the newly exposed Pot-of-Gold, then placed the Mössbauer instrument on the site for a 21-hour overnight observation.


sol 164-166, June 25, 2004: Edging Up on 'Pot-of-Gold'

Spirit spent the last few sols getting into position on the rock target "Pot-of-Gold" for an upcoming grind with the rock abrasion tool. This repositioning has not been easy due to slippage in the sandy-sloped terrain at the base of the "Columbia Hills."

On sol 164, Spirit completed an overnight alpha particle X-ray spectrometer observation on Pot-of-Gold and then gathered additional microscopic images of the rock. In the afternoon, rover planners tried to reposition Spirit from a heading of about 170 degrees to a heading of about 95 degrees to improve the instrument deployment device positioning on Pot-of-Gold for the upcoming rock abrasion tool work. The planned traverse sent Spirit past Pot-of-Gold, down a slope on the west side of "Hank's Hollow," then turned the rover to re-approach at the desired heading. The slope and slippage was greater then expected, leaving the rover at a westerly tilt of 19 degrees and almost 2 meters (6.6 feet) away from the target.

Spirit worked toward getting into position in front of Pot-of-Gold on sol 165, but given the slippage and need to avoid overshooting the target, engineers anticipated it would take at least two sols to get properly repositioned. Unfortunately, the drive made less progress than desired due in part to a collection of rocks encountered by the left rear wheel.

On sol 166, Spirit took advantage of its current position and used the gathered Mössbauer data and microscopic images of the soil in front of it before continuing the hill climb. Spirit's front wheels made it over the crest, leaving the rover at about a 13-degree tilt and still about 1 meter (3.3 feet) from Pot-of-Gold.


sol 161-163, June 23, 2004: 'Pot-of-Gold' Revealed

Spirit currently sits at the base of the "Columbia Hills" in an area called the "Hank Moore Hollow." This area has a collection of intriguing rocks on its rim, one of which, "Pot-of-Gold," will be the first target for scientists' observations.

Spirit used the microscopic imager to get an up close view of Pot-of-Gold on sol 161, but unfortunately, the images were out of focus. Rover planners attribute the blurry shots to a lower than expected rock contact prior to the imaging sequence. Spirit did successfully acquire Mössbauer observations of Pot-of-Gold on this sol.

On sol 162, Spirit was commanded to retake the microscopic images of Pot-of-Gold and do extensive observations with the Mössbauer and alpha particle X-ray spectrometer instruments. The microscopic images were successfully obtained, but a positioning fault of the instrument deployment device prevented the Mössbauer and alpha particle X-ray spectrometer observations from executing.

Spirit successfully completed the work with its instrument deployment device on sol 163, and took some additional microscopic images of Pot-of-Gold.


sol 156-158, June 16, 2004: Spirit Reaches the 'Columbia Hills!'

On sol 156, Spirit roved 42 meters (138 feet) closer to a vantage point where it could observe the hill outcrops. Some of the images that Spirit sent back revealed a small and unusual rock that piqued scientists' interest and was informally named "End-of-Rainbow."

Part of the sol 157 plan was to observe End-of-Rainbow and use the alpha particle X-ray spectrometer, Mössbauer spectrometer and microscopic imager to study the "Shredded" soil target. However, the command load for sol 157 never made it to Spirit. Further analysis indicated that the problem had to do with the frequency drift associated with the colder temperatures on Mars as the planet moves into its southern winter season. This was an anticipated problem, and the rover team has already imposed some strategies that will help to prevent the problem in the future.

So, Spirit got a break on sol 157 and began sol 158 with nicely charged batteries. She executed the activities originally planned for sol 157, and then began to drive a bit closer to End-of-Rainbow. Although the direct path to End-of-Rainbow would be only a 4-meter (13 feet) drive, it was deemed too steep and hazardous by the rover team, so they planned a multi-stepped drive that could get the rover to the target safely. On sol 158, the first part of the drive was completed, putting Spirit a little farther away from the End-of-Rainbow target, but with a straight shot to the rock for sol 159.


sol 152-155, June 15, 2004: Are We There Yet?

On sol 152, Spirit continued its journey toward the "Columbia Hills" and completed an 83-meter (272 feet) drive that brought its total odometry to 3.2 kilometers (2 miles). After the drive, the rover completed some remote sensing that brought more details of the hills into view.

Spirit roved another 70 meters (230 feet) on sol 153, and 49 meters (161 feet) on sol 154. After the drive on sol 154, Spirit attained a miniature thermal emission spectrometer scan of the hills that will help scientists identify what the hills are made of.

As of sol l55, Spirit was roughly 50 meters (164 feet) from the base of the target location at the Columbia Hills. Spirit reached this location after a 23-meter (75 feet) drive that ended with the rover at a maximum tilt of 20 degrees. 20 degrees is well below the safe limit for tilt and was 3 to 4 degrees below the estimated tilt for this traverse.


sol 148-151, June 09, 2004: Spirit Surpasses 3 Kilometer Mark!

During sols 148 through 151, Spirit advanced significantly closer to the "Columbia Hills" and now sits only 220 meters (722 feet) from its first target at the base, a location informally named "Spur B."

Sol 148 was a driving sol, with Spirit completing a 64.7-meter (212.3 feet) engineer-directed drive. This put the rover in position for some sol 149 work with the robotic arm, and provided a great view of the Columbia Hills.

On Sol 149, Spirit took a break from driving and surveyed the Columbia Hills with the panoramic camera and mini thermal emissions spectrometer. After that, the rover attained an alpha particle X-ray spectrometer observation of the filter magnet and capture magnet. Spirit takes a look at its magnets every now and then to assess what magnetically susceptible materials have accumulated. The last magnet check was on sol 92.

Spirit used its alpha particle X-ray spectrometer and Mössbauer spectrometer to observe a rock called "Joshua" on sol 150. Unfortunately, the rest of the sol's planned work with the instrument deployment device did not take place because of a command anomaly, which made Spirit think that a collision between the rock abrasion tool and the forearm might occur. Therefore, the tool change and all subsequent arm motions were prevented for the rest of the sol.

Spirit was back to business on sol 151, and finished observing Joshua and the science magnets with the tools on the instrument deployment device. After that, the rover was off, and successfully completed a 73-meter (240 feet) drive toward the Columbia Hills.


sol 145-147, June 08, 2004: Keep On Rovin'

On sol 145, Spirit completed a 43-meter (141 feet) engineer-directed drive and then spent two hours roving another 55 meters (180 feet) using the autonomous navigation software.

Spirit roved 61 meters (200 feet) on sol 146, and 52 meters (171 feet) on sol 147. At its current rate, the rover is on schedule for a sol 160 arrival at the base of the "Columbia Hills."

Spirit currently has a total of 2.98 kilometers (1.85 miles) on its odometer.


sol 143-144, June 03, 2004: Roving Toward the Hills

Spirit began sol 143 using the panoramic camera to image its surroundings. After a restful nap, the rover began driving and advanced 69 meters (226.4 feet) in an engineer-directed drive toward the "Columbia Hills." After doing some mid-drive science imaging, Spirit attempted additional driving using its autonomous navigation software, but detected hazards in the immediate vicinity of the rover and therefore covered no additional ground.

On sol 144, Spirit covered 24.4 meters (80 feet) in another engineer-directed drive. Once again, the terrain was too rough to permit further driving beyond this point using the autonomous navigation software. On sol 145, Spirit will continue driving in its quest for the hills.


sol 140-142, June 02, 2004: Back To Business

Spirit spent most of sol 140 investigating the trench it dug on sol 135. It got an up-close look at the trench with the microscopic imager and then began a five-and-a-half hour integration with the Mössbauer spectrometer. Doing double duty, Spirit surveyed the "Columbia Hills" with the panoramic camera and miniature thermal emission spectrometer during the Mössbauer observation. Following the afternoon Odyssey communications window, Spirit changed tools and began an overnight integration on two targets with the alpha particle X-ray spectrometer.

On sol 141, Spirit continued to observe the trench with the Mössbauer spectrometer and microscopic imager. The rover also obtained panoramic camera images of its surroundings while doing work with the robotic arm. It then stowed the instrument deployment device and backed up 0.85 meters (2.8 feet). Spirit spent most of the afternoon observing the trench using the miniature thermal emission spectrometer.

Spirit got a chance to stretch its wheels and do some driving on sol 142, but before taking off, the rover finished the trench observations with some panoramic camera imaging. Then it was time to rove. Spirit completed a 30-minute, engineer-directed drive and then turned the wheel over to the autonomous navigation software for another hour and 15 minutes of driving. Spirit roved a total of 61 meters (200.1 feet) closer toward the Columbia Hills.

Spirit has 2,647.7 meters (1.65 miles) on its odometer, and just over 620 meters (.4 miles) to rove before reaching the base of the Columbia Hills.


sol 136-139, June 02, 2004: Spirit Recovers from a Low Probability Software Error

Spirit had plans to spend sols 136 through 139 observing its surroundings with the remote sensing instruments on its mast, and then exploring the trench it dug on sol 135 with the instruments on the robotic arm. However, an anomaly on sol 136 restricted the rover's activity, allowing Spirit to achieve only remote science objectives during the four-sol segment. Spirit has since fully recovered and has resumed normal science operations.

On sol 136, engineers sent Spirit its commands and received the beep confirming that they were running. However, the afternoon pass by NASA's Mars Odyssey orbiter did not provide any data, and the orbiter reported that it had not heard from Spirit's UHF antenna. Engineers first thought was that the signal might have been blocked by the "Columbia Hills" because of the low elevation pass of Odyssey. The telecommunications team disagreed with this hypothesis and thought something might be wrong. Scientists and engineers would have to wait until the afternoon of sol 137 for their next communications opportunity.

During sols 136 and 137, engineers executed a number of communication trials with Spirit, but did not receive any telemetry from the rover, or have any indication of what had gone wrong until finally data came back from a sol 137 afternoon pass by NASA's Mars Global Surveyor. That pass revealed that on sol 136, Spirit's software had experienced an extremely low probability error that rebooted the computer and terminated all the sequences. This error created a domino effect of communication difficulties and explained why engineers had not been able to make contact with the rover. All the anomaly events are understood.

Sol 138 was spent recovering the state of the rover, including reestablishing a master sequence, restoring high-gain antenna communications, and reinitializing the panoramic camera mast actuators whose positions had been marked as unknown.

On sol 139, Spirit performed the remote-sensing observations that had been lost along with some observations coordinated with Mars Global Surveyor that had been planned for sol 138. All activities on sol 139 completed successfully, which verified that Spirit had returned to normal science operations.

Engineers have developed a way to reduce even further the probability of encountering this particular error again and reported that on the bright side, Spirit was able to fully charge its batteries during the anomaly.

Sol 140 picked up with the original plan for Sol 137, performing in-situ work in the trench.


sol 134-135, May 27, 2004: Taking Time to Trench

Spirit roved an impressive 109.5 meters (359.3 feet) on sol 134. Two hours of the drive were guided by the autonomous navigation system. After the long traverse, Spirit completed an hour of post-drive science observations with the panoramic and navigation cameras and mini thermal emission spectrometer. The rover finished the sol healthy and ready for another day on Mars.

After so much driving on sol 134, Spirit got a break and spent sol 135 doing in-situ science investigations of its surroundings. It began the sol observing nearby soil with the alpha particle X-ray spectrometer and Mössbauer spectrometer. It then used the microscopic imager to see the soil up close. After stowing the instrument deployment device, Spirit used its wheels to dig a trench and then imaged the trench with the cameras on the mast.

Spirit's odometer now reads 2,585.52 meters (1.6 miles). The rover still has 680 meters (0.42 miles) to go before reaching the base of the "Columbia Hills," but will likely get there before sol 160.


sol 131-133, May 20, 2004: Spirit Gets an Unexpected Break

Spirit continued its trek to the "Columbia Hills" over the past four sols, but took an unplanned break on Sols 131 and 132 due to a software fault on sol 131. That fault left rover planners with some uncertainty about Spirit's final position and attitude, so Sol 132 was spent re-establishing that knowledge with panoramic, navigation and hazard avoidance camera imaging of the rover's surroundings. The unplanned break did have a silver lining though; it resulted in fully charged batteries, paving the way for a long drive on Sol 133. Spirit roved 113 meters (370.7 feet) on Sol 133, with a record 78-meter (256 feet) autonomous navigation segment. The previous record for an autonomous navigation drive was 62 meters (203.4 feet) on sol 125. Spirit's odometer now reads 2473 meters (1.53 miles) and it is roughly 780 meters (.5 miles) from the Columbia Hills and in excellent health.

So what went wrong on sol 131? The flight software team is uncovering the details, but it appears that the error occurred within a 3-microsecond window of vulnerability when a "write" command was attempted to a "write-protected" area of RAM. The flight software team believes this is an extremely low probability event, and has not adjusted the planning process to avoid the miniscule period of vulnerability. Opportunity has the same vulnerability to the fault.


sol 127-130, May 17, 2004: Spirit Roving Right Along

Spirit spent most of sol 127 continuing its drive toward the "Columbia Hills." The rover put approximately 70 more meters (229.7 feet) on its odometer and then took an hour-and-20-minute siesta. After the drive, Spirit took observations with the panoramic camera, navigation camera and mini thermal emission spectrometer.

Spirit began sol 128 by completing a panoramic camera observation of a rock target called "Flat Head." The rover then rested up for a couple of hours before embarking on a 90-meter (295 feet) drive toward the hills. Once the drive was complete, Spirit completed its standard post-drive observations.

Sol 129 began successfully, but Spirit encountered a couple of difficulties before the martian day was over. After waking, Spirit performed 45 minutes of science observations and then settled down for a morning nap. With plenty of energy stored, it was time to drive. Spirit roved 31 meters (102 feet) across the surface in an engineer-directed drive and then spent 45 minutes using its autonomous navigation system to try to drive down the side of a small ridge. The backside slope of the ridge was too steep, and the autonomous navigation system had Spirit turn in an attempt to find another way down. Unfortunately, a couple of large rocks close to the ridge prevented Spirit from finding a safe path down. At the end of the drive sequence, Spirit was supposed to complete a "stutter step" to get in proper position to do work with the instrument deployment device on sol 130. Unfortunately, the rover was unable to complete this final positioning or the ultimate post-drive imaging, so sol 130 was mostly a drive sol.

Spirit has 2,291.92 meters (1.4 miles) on its odometer and is approximately 936 meters (.6 miles) from Columbia Hills. The rover is on track to reach the Columbia Hills by sol 160.


sol 124-126, May 12, 2004: Spirit Speeds to 'Lead Foot'

Spirit drove 80 meters (262.5 feet) on sol 124, bringing its total odometry to 1,909.52 meters (1.2 miles). Spirit has less than 1.2 kilometers (.75 mile) to go before reaching the base of the"Columbia Hills," and will reach them by sol 160. Later in the martian day, after completing the sol 124 drive, Spirit took a 360-degree afternoon panorama of its surroundings with the navigation camera.

On sol 125, Spirit continued driving and set a new one-sol driving record of 123.7 meters (405.8 feet). Science on Sol 125 included morning atmospheric sky and ground remote sensing, mini thermal emission spectrometer observation of the sol 126 instrument deployment device work volume, imaging with the panoramic camera, and cloud observations.

After the long sol 125 drive, Spirit was in perfect position to work with the instrument deployment device on sol 126. This included alpha particle X-ray spectrometer, Mössbauer and microscopic imager work on a target called "Lead Foot" (in honor of the big drive on sol 125). The Mössbauer was used as the feeler for all these activities but touched down on rocks rather than soil at the "Lead Foot" location, compromising the Mössbauer and microscopic imager data (images out of focus). Spirit also did some driving on this sol, and added 55.6 meters (182.4 feet) to the odometer, bringing Spirit's new drive total to 2,089 meters (1.3 miles). At the end of the sol, Spirit successfully executed a sequence that used the panoramic camera to find the Sun and correct for accumulated rover attitude errors.


sol 121-123, May 10, 2004: Spirit Surpasses the One-Mile Mark!

On sol 121, after a brief nap, Spirit conducted atmospheric measurements before continuing its trek toward the "Columbia Hills." A 96.8 meter (318 feet) drive that consisted of about half direct drive and half auto-navigational drive broke Spirit's last one-sol distance traveled. That drive brought the mission total to 1,669 meters (1.04 miles), flipping the rover's odometer over the one-mile mark.

Sol 122 was a touch-and-go day, starting with a half-hour alpha particle X-ray spectrometer integration, a one-hour Mössbauer integration and a set of four microscopic images all on the same patch of soil. Panoramic camera and miniature thermal emission spectrometer data were also obtained before an afternoon nap. The bulk of the afternoon was spent driving another 65 meters (213 feet).

Sol 123 started off with Panoramic camera and miniature thermal emission spectrometer observations for near-field surveys, atmospheric studies, and localization. Spirit then took a half-hour nap, followed by the day's drive. This sol consisted of another 48-meter (about 157-feet) direct drive, the mid-drive survey and localization remote sensing, and then 47-meters (about 154 feet) of driving using auto-navigation. The total was 95.2 meters (312 feet), bringing the mission total to 1830 meters (1.14 miles).


sol 118-120, May 6, 2004: 'Columbia Hills' on the Horizon

Spirit is now approximately 1.7 kilometers (1 mile) away from the base of the "Columbia Hills" after three long sols of driving. Its odometer currently reads 1,566 meters (.97 miles) and counting.

Sol 118 was a record-breaking driving sol for Spirit. The Gusev Crater rover moved 92.4 meters (303 feet) across the surface in one sol, breaking its previous record of around 90 meters (295 feet). The Opportunity rover still has Spirit beat with a one-sol driving record of 140 meters (459.3 feet).

Sol 119 proved to be a more difficult sol for Spirit. An uplink configuration error prevented the sequence load from successfully getting on board the rover. Rover controllers took advantage of the down day by deleting afternoon communication sessions and enabling the rover to charge its battery during a long afternoon nap.

It was back to business as usual on sol 120. Before embarking on its drive, Spirit imaged a rock called "Tulula" with the panoramic camera. The rover then successfully executed a blind drive before using the autonomous navigation system to continue into uncharted territory. After reaching the time-of-day driving limit, Spirit turned and performed penultimate (next to last stop) imaging. The next move would have taken the rover 85 centimeters (33.5 inches) to its ultimate stopping point, but did not execute because Spirit was facing a small sand ridge that was perceived as a hazard. Without a penultimate/ultimate image pair, rover controllers could not be sure that the area underneath the rover was clear of hazards for instrument arm deployment. As a result, Sol 121 will be another driving sol that controllers hope will place Spirit in a suitable location to use the instruments on its instrument deployment device.


sol 114-117, May 3, 2004: Spirit explores the 'Big Hole' trench

On Sol 114, which ended at 9:49 a.m. April 29 PDT, Spirit performed a lot of science activities in the trench called "Big Hole" using the microscopic imager, Mössbauer spectrometer and alpha particle X-ray spectrometer. Opportunity also studied the rover tracks and the crater rim.

Sol 116 started with a repeat of the microscopic imaging of a target in the trench due to minor communication glitches on sol 115. Spirit then stowed the arm, backed away from Big Hole trench, and took panoramic camera images of the trench before it continued on its trek toward the Columbia Hills. The drive on sol 116, which ended at 11:08 a.m. May 1 PDT, established a new drive record of 90.8 meters (298 feet) for Spirit!

On sol 117, which ended at 11:47 a.m. May 2, Spirit drove 37 meters (121 feet) to a small ridge, where the vehicle experienced a pitch up of 12.2 degrees. Engineers believe that the change in tilt caused the vehicle to recompute its "goodness map," which helps the rover autonomously drive over the martian terrain, and the rover declared that it was not safe to continue its drive. One good thing that came out of this is that the end-of-drive tilt positioned the solar arrays to maximize afternoon solar exposure, and the rover's battery state of charge is in good health.


sol 112-113, Apr 29, 2004: A Drive and a Dig

Spirit took it easy the morning of sol 112, which ended at 8:30 a. m. PDT on April 27, , and didn't begin operations until 11:45 a.m. Mars Local Solar time, to conserve energy for an afternoon drive. Before taking off, Spirit gathered some soil and atmospheric observations with the mini thermal emission spectrometer and panoramic camera.

Then the drive began. Spirit's updated autonomous navigation software proved its worth again this sol. During a long auto-navigation segment, the rover encountered a hazard and was able to back up and find a way around it. Spirit continued to drive backwards towards its intended goal point, using the rear hazard avoidance cameras to navigate the way. When the allotted drive time was up, Spirit turned back around and made one last short drive to its resting place for the night. Spirit's odometer records backwards and forwards driving and logged another 88.6 meters (290.7 feet) for the sol 112 drive. The actual distance covered was about 60 meters (197 feet).

On Sol 113, which ended at 9:09 a.m. PDT on April 28, Spirit woke up earlier than normal, 9:00 a.m. Mars Local Solar time, to do morning atmospheric science. One objective of the early sky scan was to image morning clouds with the panoramic camera. Spirit then began an intense study of a soil spot called "MayFly." During her examination of the area, Spirit took panoramic camera and mini thermal emission spectrometer images in parallel, conducted a two-hour Mössbauer integration and finished off with a look through the microscopic imager. The rover then stowed the instrument arm to prepare for digging a trench.

Rover planners intended for Spirit to use its wheels to dig a trench at the MayFly spot, but hazard avoidance camera images of the area showed a potato-size rock that could have potentially fallen into the wheel hollow in the process. Rather than take that risk, controllers decided to back the rover up 10 centimeters (3.9 inches) to a clearer spot. After the final positioning, Spirit used its wheels to dig a 6-centimeter (2.4-inch) trench. Spirit finished the sol with hazard avoidance camera images of the trench, which was used to plan Mössbauer, alpha particle X-ray spectrometer and microscopic imager work on sol 114.

On sol 114, which ended at 9:49 a.m. PDT on April 29, 2004 Spirit continued to investigate the trenched area with the Mössbauer spectrometer, alpha particle X-ray spectrometer and the microscopic imager.


sol 110-111, Apr 27, 2004: Spirit Continues to Drive

After a successful weekend of driving on sols 108 and 109, Spirit kicked off its week with a 140-meter (459.3 feet) drive over sols 110 and 111 toward its destination at the base of the "Columbia Hills."

Spirit began sol 110, which ended at 7:10 a.m. PDT on April 25, 2004, with a stretch of its "arm" to take microscopic imager pictures of an area of soil called "Waffle Flats." It then placed the Mössbauer spectrometer instrument on that spot for a 90-minute integration. Spirit did double-duty and was able to get panoramic camera and mini thermal emission spectrometer images of the area for localization and science purposes while the Mössbauer was at work.

Spirit then stowed its instrument deployment device and began an 80-meter (262.5 feet) drive, half of it directed by rover planners and half using the autonomous navigation software. During the autonomous navigation portion, the rover detected a hazard and did not complete the final short-drive intended at the end of the journey. Images from the front hazard avoidance camera show no sign of a hazard, leaving rover controllers with a bit of a mystery to investigate.

Following the drive, Spirit took panoramic camera and navigation camera images in the drive direction and performed atmospheric science with the panoramic camera and mini thermal emission spectrometer.

Sol 111, which ended at 7:50 a.m. PDT on April 26, 2004, was also a sol full of driving for Spirit. After acquiring panoramic camera images of its surroundings and completing atmospheric science with the panoramic camera and mini thermal emission spectrometer, the rover began its drive.

Spirit successfully completed a 60.8-meter (199.5 feet) drive toward the Columbia Hills and then acquired navigation and panoramic camera images of the driving direction. Spirit ended the day with mini thermal emission spectrometer observations of the soil and then a coordinated mini thermal emission spectrometer and panoramic camera study of the atmosphere.


sol 106, Apr 23, 2004: A Little Science, a Lot of Driving

Spirit spent most of sol 106, which ended at 4:32 a.m. PDT on April 21, performing remote sensing on the inside of "Missoula Crater." It acquired panoramic camera and mini thermal emission spectrometer panoramas and navigation camera images of the crater, along with some panoramic camera images looking back toward "Bonneville" crater.

On the morning of sol 107, which ended at 5:12 a.m. PDT on April 22, Spirit got some atmospheric and cloud observations with the panoramic camera and mini thermal emission spectrometer. The rover then took a look with the panoramic camera at three targets called "Gratteri Piazza," "Wallula Gap," and "Clark Fork." Finally it was time to drive. Spirit completed a 73.8-meter (242-feet) traverse that included a jog around a sandy hollow to the east of Missoula. Most of the drive was in the southeast direction on course to the "Columbia Hills." After the drive, Spirit acquired additional panoramic camera and navigation camera observations. The total odometry at the end of sol 107 was 976.77 meters (.6 miles).

Spirit continued driving toward the Columbia Hills on sol 108, which ended at 5:51 a.m. PDT on April 23, and will drive some more on sol 109, which ends at 6:31 a.m. on April 24.

The wakeup song on sol 109 was "(Take me) Riding in my Car" by Woodie Guthrie.


sol 102-104, Apr 19, 2004: 'Missoula Crater' in Sight

Spirit had a busy weekend, culminating with a 75-meter (246-feet) drive toward "Missoula Crater" on sol 103, which ended at 2:33 a.m. PST on April 18. The sol before the drive, Sol 102, which ended at 1:54 a.m. on April 17, was an easier day for Spirit. Its main objectives were to use the panoramic camera and mini thermal emission spectrometer to acquire photometric and atmospheric measurements.

Before beginning the drive on sol 103, Spirit took panoramic camera images to help planners localize the rover during the long traverse. It then used the panoramic camera and mini thermal emission spectrometer to take a look back at the wheel tracks. Once this information was onboard, the rover began to drive.

Rover controllers planned the first 37 meters (121.4 feet) of the drive, but Spirit used the updated autonomous navigation software to see it through the remaining 38 meters (124.7 feet). Between the two drives, Sprit imaged its surroundings with the panoramic and navigation cameras for context. At the end of the 75-meter (246-feet) drive, Spirit rested a mere 40 meters (131.2 feet) from its destination at the rim of "Missoula Crater." From that spot, it took mini thermal emission spectrometer observations of the sky and ground along with panoramic and navigation camera images to plan the next drive.

Sol 104, which ended at 3:13 a.m. PST on April 19, was a remote sensing day for Spirit. It included a search for dust devils and panoramic camera imaging of Mars' moon Phobos as it transits across the sun and sets.


sol 100, Apr 15, 2004: A Century of Sols on the Surface

With 100 sols under her belt and 706.5 meters (.44 miles) on her odometer, Spirit keeps on roving toward the Columbia Hills.

Spirit began sol 100, which ended at 12:35 a.m. PDT, on April 15, 2004, by closing the doors on the alpha particle X-ray spectrometer, stowing the robotic arm and backing up from the rock called "Route 66" in preparation for an afternoon drive. Before taking off, Spirit used the miniature thermal emission spectrometer to examine a patch of Route 66's surface that had been scrubbed in a daisy-shaped mosaic of brushings by the rock abrasion tool. In the early martian afternoon, the rover began a 64-meter (210 feet) drive, Spirit's longest one-sol drive so far. The final 24 meters (78.7 feet) of the drive were navigated with the enhanced autonomous navigation capabilities of Spirit's newly uploaded software. The new software has nearly doubled the meters-per-hour rate to 32 (105 feet-per-hour).

After the traverse, Spirit completed post-drive imaging and used the miniature thermal emission spectrometer on sky and ground targets.

Sol 101, which will end at 1:14 a.m. PDT on April 16, 2004, will be a remote science and driving sol for Spirit as she continues to make her way toward the Columbia Hills.


sol 99, Apr 14, 2004: Brushing Down Route 66

Spirit began Sol 99, which ended at 11:55 p.m. PDT on April 13, 2004, by doing a systematic ground survey with the miniature thermal emission spectrometer. After that, the rover completed a six-position brush mosaic on the rock "Route 66" with the rock abrasion tool. Once the brushing was complete, Spirit analyzed the area with the microscopic imager and Mössbauer spectrometer.

The afternoon science for the sol included imaging of rocks called "Back Lot" and "Cameo" with the panoramic camera and the miniature thermal emission spectrometer. Spirit took a short nap and woke up for the afternoon Odyssey pass.

During the martian night, Spirit changed from using the Mössbauer spectrometer to using the alpha particle X-ray spectrometer.

Sol 100, which will end at 12:35 a.m. PDT, April 15, 2004, will be a sol full of roving as Spirit continues toward the "Columbia Hills."


sol 98, Apr 13, 2004: Refreshed and Ready to Rock and Rove

On Sol 98, which ended at 10:36 p.m. PST on April 12, Spirit woke up to the song "Where Is My Mind?" by The Pixies in honor of its software transplant. The good news is that Spirit's "mind" is updated and operating as expected.

Controllers gave the go to reboot the rover's computer, which would then run the new software during the morning of sol 98. The command was sent, and a little over a half hour later, engineers saw the carrier beep that indicated that the command was received. Spirit went to sleep for several minutes after that, and then woke up, rebooting into the new software. It then initiated a high-gain antenna session at 12:30 p.m. Mars Local Solar time, and engineers saw that the new version of the rover software was running properly.

After confirmation that the new software was running as expected, engineers ran some clean-up activities and breathed a sigh of satisfaction.

The new software provides several improvements. It enhances the rovers' mobility, and should allow Spirit to go much farther each sol by reducing how often it has to take images and generate new three-dimensional maps. A deep-sleep mode has been added, mainly to resolve the heater that is stuck in the "on" position on the Opportunity rover. However, someday Spirit may find a use for this mode as well. The new software also mitigates the memory problem Spirit had on sol 18, and seems to be making a difference already. Spirit's unallocated memory jumped from 2.0 megabytes to 3.3 megabytes after the new software compacted the flash directories when it booted.

It's back to regular operations for Spirit on sol 99, ending at 11:15 p.m. PST on April 13, brushing a six-spot mosaic on the rock target "Route 66." Spirit will then take microscopic imager images and spectrometer measurements before the sol is complete.


sol 94, Apr 09, 2004: Spirit Stands Down for Flight Software Update

Spirit began a four-sol stand-down on sol 94, which ended at 8:37 p.m. on April 8, 2004. During this time, the rover will receive a flight software update that should make its remaining martian days even safer and more productive. The upload will run through sol 97 with a rover re-boot on sol 98, Monday, April 12. Opportunity will be receiving the same update package in upcoming sols.

Spirit is currently parked in front of the rock called "Route 66," and will remain there for the duration of the flight software update, with the Mössbauer spectrometer integrating on the rock, and the alpha particle X-ray spectrometer pointed up to the sky.

The flight software update package includes three key changes. First is an update to the autonomous navigation software that will allow Spirit to travel longer distances autonomously over the extremely rocky Gusev Crater terrain. The current autonomous navigation software sometimes gets stuck when it detects a hazard that it can't navigate around. The new version will allow Spirit to turn in place to find the best possible path.

The second part of the flight software update will allow Spirit to recover more easily from an anomaly like the one that occurred on sol 18. Although operational processes and software have already been updated to prevent something like this from ever happening again, engineers have included additional safety nets in the software that would allow the rover to autonomously react to a similar anomaly and recover to a more stable state.

The third portion of the update is specific to Opportunity and is intended to mitigate against energy loss associated with the stuck heater on Opportunity's instrument deployment device. The fix allows rover planners to put the rover in a deep sleep mode, where the batteries are totally removed from being able to power the stuck switch. Therefore, with no power reaching the stuck heater switch, the Opportunity rover battery will not be drained. Rover controllers will not initiate the deep sleep capability on Spirit unless it becomes necessary.


sol 93, Apr 08, 2004: Last Sol for Spirit Science

Spirit began sol 93, which ended at 7:57 p.m. PST on April 7, by heating the high gain antenna. Spirit then took some calibration measurements and navigation camera imaging of the alpha particle X-ray spectrometer's placement on the magnet.

Around 10:30 a.m. Mars Local Solar time, Spirit moved its instrument deployment device out of the way to take hazard avoidance camera images of the rock target called "Route 66." The rover then operated the Mössbauer spectrometer for a four-hour integration. During the integration, Spirit captured its current location with a panoramic camera mosaic toward the "Columbia Hills" and the rover tracks.

After a short nap, Spirit took mini thermal emission spectrometer observations of the rover tracks, and rock targets called "Everest" and "Pisa." The rover completed the Mössbauer integration and then placed it on Route 66 with the alpha particle X-ray spectrometer pointed up to the sky. The instrument deployment device will remain in this position during the flight software load time period, allowing for long integrations of the Mössbauer on Route 66 and the alpha particle X-ray spectrometer on the sky.

Sol 94, which ends at 8:37 p.m. PST on April 8, will be the beginning of the four-sol flight software upload. Before rover operators begin loading the updated software, they will command Spirit to perform a sunrise imaging operation. The flight software update will continue through sol 97 with a rover reboot on sol 98, Monday April 12.


sol 92, Apr 07, 2004: Monitoring Magnets on Mars

Spirit awoke on sol 92, which ended at 7:18 p.m. PST on April 6, and completed some early morning panoramic camera sky and ground measurements. Spirit also took a look at the capture and filter magnets with the panoramic camera prior to taking a short mid-morning nap. Upon wake-up around 12:30 p.m. Mars Local Solar Time, the rover opened the doors on the alpha particle X-ray spectrometer and took 3 images of each magnet. Spirit also placed the Mössbauer spectrometer on the capture magnet and began an integration.

In the afternoon, Spirit completed coordinated observations with the thermal emission spectrometer instrument on NASA's Mars Global Surveyor orbiter. The observations involved miniature thermal emission spectrometer pre-flight, simultaneous, and post-flight sky and ground measurements. Spirit also collected a panoramic camera opacity observation.

Early on Sol 93, which ends at 7:57 p.m. on April 7, the rover will switch the instruments on its instrument deployment device from the Mössbauer spectrometer to the alpha particle X-ray spectrometer. Sol 93 is the last day for newly planned science observations, as Spirit will be getting a flight software update during sols 94-98.


sol 91, Apr 05, 2004: Spirit Achieves Mission Success

Spirit woke up on sol 91, which ended at 6:38 p.m. PDT on April 5, 2004, as if it were any other martian day, but this one was special. Finishing 90 sols of surface operations since landing day marked completion of the last of the official success criteria for Spirit's prime mission. The rover team at JPL had checked off the next-to-last box for mission success two days earlier, when a drive of 50.2 meters (165 feet) took Spirit's total travel distance over the 600-meter (1,969 feet) mark.

The martian day for sol 91 started with some remote sensing observations of the sky and ground as well as navigation camera images of the landscape to the east. Then the rover completed miniature thermal emission spectrometer ground surveys and imaged the sky and ground with the panoramic camera. After a short nap, Spirit acquired some pre-drive imaging including a super-spectral look at an interesting spot in front of the rover.

Early in the martian afternoon, Spirit began a 1.35-meter (4.4-foot) drive to get closer to a rock called "Route 66." Once the drive was finished, the rover analyzed the instrument deployment device's work volume with hazard-avoidance camera images and a stare by the miniature thermal emission spectrometer. A quick adjustment of 0.8 meters (2.6 feet) put the rover in perfect position and completed the drive.

Spirit spent the afternoon taking a systematic soil survey with the panoramic camera, a 13-filter image of the destination informally named "Columbia Hills," and acquiring miniature thermal emission spectrometer data of the same locations.

Spirit will spend sol 92, which will end at 7:18 p.m. PDT on April 6, 2004, analyzing its capture magnet and filter magnet with its Mössbauer spectrometer and microscopic imager. The rover will also complete coordinated observations with the Mars Global Surveyor and switch tools to the alpha particle X-ray spectrometer for an overnight measurement.


sol 88, Apr 02, 2004: Cruisin' Down the Crater Side

Spirit spent most of Sol 88, which ended at 3:39 p.m. PST on April 2, driving toward the "Columbia Hills." Before beginning the drive, Spirit acquired some pre-drive remote sensing, which included panoramic camera photometry and a mini thermal emission spectrometer stare of the rock called "Carlsbad."

Spirit then began the 35-meter (114.8 feet) combination directed and autonomous navigation drive down the rocky, ejecta-covered side of "Bonneville Crater." Fifteen meters (49.2 feet) of the drive were directed by rover planners and did not require the rover to use its hazard avoidance software. The remaining 20 meters (65.6 feet) were navigated by Spirit autonomously and did cause the rover to make some back and forth adjustments as it avoided what it perceived to be a depression hazard in its path. Rover controllers will look at hazard avoidance camera images tomorrow to confirm the details of Spirit's behavior.

Spirit will begin Sol 89, which ends at 4:19 p.m. PST on April 3, using the instrument deployment device on a rock target in front of it, followed by another drive toward the Columbia Hills.


sol 87, Apr 02, 2004: Bye-Bye 'Bonneville'

Spirit began sol 87, which ended at 3:00 p.m. PST on April 1, with some morning atmospheric science, and then took a last look at the rock "Mazatzal" with the panoramic and navigation cameras. Then the rover was off, traveling 36.5 meters (119.8 feet) down the side of "Bonneville" Crater headed south toward the "Columbia Hills."

The drive was a combination of "blind" and autonomous navigation roving. The blind segments of the drive are used when rover planners can see all possible hazards and command the rover to just "go." The autonomous navigation portion allows the rover to make decisions based on the terrain presented. While the blind segments of the sol 87 drive were successful, the second to the last autonomous navigation sequence did not complete in the allotted time, causing a drive "goal" error. As a result, Spirit was not able to execute the complete commanded drive, and roved 36.5 meters (119.8 feet) of the 65-meter (213.3 feet) planned drive.

Following the drive, Spirit took navigation and panoramic camera pictures in her drive direction and performed atmospheric and soil science with the panoramic camera and mini thermal emission spectrometer.

Spirit will spend most of sol 88, which ends at 3:39 p.m. PST on April 2, driving toward the Columbia Hills.


sol 86, Mar 31, 2004: Brushing the Dust Off 'Missouri'

Spirit began sol 86, which ended at 2:20 p.m. PST on March 31, 2004, by waking up and heating the panoramic mast assembly to complete sky and ground stares with the miniature thermal emission spectrometer. Spirit completed the alpha particle X-ray spectrometer integration on the hole made by the rock abrasion tool and then took a 45-minute nap.

Once Spirit woke up, it began the 6-position rock abrasion tool brush mosaic on the target "Missouri" on the rock called "Mazatzal." Once this was completed successfully, the rover's arm was stowed.

Spirit then rolled backwards .9 meters (2.95 feet) to correctly position itself to acquire mini thermal emission spectrometer imaging of the newly brushed mosaic, and the previously ground hole. In addition, Spirit took sky and ground stares and panoramic camera images of the upcoming drive direction. The sol ended with mini thermal emission spectrometer stares at the "Columbia Hills" and an afternoon pass by NASA's Mars Odyssey orbiter.

Sol 87, which ends at 3:00 p.m. PST on April 1, 2004, will be a driving day for Spirit as it begins what could be a record-breaking journey toward the Columbia Hills.


sol 85, Mar 30, 2004: Looking Inside Mazatzal

Since the rock abrasion tool completed a full-circle grind into the "New York" and "Brooklyn" targets on the rock "Mazatzal," it was time for Spirit to do some analysis. Spirit spent much of Sol 85, which ended at 1:41 p.m. PST on March 30, successfully operating the instruments on its robotic arm to take a more detailed look inside Mazatzal.

Although all the operations were completed successfully on Mars, the rover team spent most of the morning and afternoon on Earth worrying. After the team sent the uplink to Spirit, they waited for the standard "beep" that confirms the sequence reached Spirit and was activated. This beep, and an expected one 10 minutes later were not acquired, and engineers proceeded to trouble-shoot what might have gone wrong. No errors could be found, and finally a successful afternoon Odyssey communications pass provided 75 megabits of data, indicating that all the sequences were in fact onboard the rover and that all the planned sol activities had completed successfully. Like worried parents, the rover team members breathed a collective sigh of relief, and are now looking into possible causes of the failure to detect the beep.

As planned, Spirit began sol 85 by receiving the uplink and then taking a one-hour nap. After waking, the rover took panoramic camera images of the rock abrasion tool and of the ratted hole in Mazatzal. Before the panoramic camera work was done, Spirit took some final shots of "Bonneville" crater. Some of those images might contribute to a super-resolution image of the heatshield remnants on the far wall. Spirit also took some images to try to catch a dust devil in action.

After the panoramic camera activity, Spirit used the microscopic imager to take a 5-position pseudo-color mosaic of the Mazatzal rock abrasion tool hole. Then the Mössbauer spectrometer was placed in the hole and began an overnight integration.

A little after 2 p.m. Mars Local Solar Time, the last miniature thermal emission spectrometer sections of Bonneville crater were acquired, followed by a set of panoramic camera images of the drive direction. In the late afternoon, Spirit used the mini thermal emission spectrometer to acquire ground and sky stares, which will be complemented by another set early tomorrow morning. Shortly after the 2 a.m. Mars Global Surveyor pass, the arm will change tools from the Mössbauer spectrometer to the alpha particle X-ray spectrometer for an integration in the rock abrasion tool hole through 9:20 a.m Mars Local Solar Time on Sol 86.

The rock abrasion tool will be back to work on sol 86, which will end at 2:20 p.m. PST on March 31, 2004, brushing a 6-spot mosaic on another portion of the rock Mazatzal called "Missouri." The mini thermal emission spectrometer will analyze the brushed area and then Spirit will begin a 5-sol drive toward the Columbia Hills.


sol 84, Mar 30, 2004: Rat Bears Down on "Brooklyn"

The angular nature of the rock called "Mazatzal" required some extra rodent power over the weekend. The latest grind by Spirit's rock abrasion tool (the RAT) resulted in that tool's deepest hole yet, nearly 8 millimeters (0.31 inches). The rover was inspired to tackle the target "Brooklyn" right next to its "New York" bull's-eye by the Beastie Boys' "No Sleep Till Brooklyn" on its 83rd sol, which ended at 12:22 p.m. PST on March 28.

Spirit's 84th sol, which ended at 1:01 p.m. PST on March 29, was planned as a day of investigation. The miniature thermal emission spectrometer and panoramic camera made successful observations of the crater informally named "Bonneville," but planned operations of the rover arm were not executed due to a switch on the Mössbauer spectrometer getting momentarily stuck. After a successful Mössbauer integration, the instrument was pulled back from Mazatzal, but one of two contact switches did not indicate a no-contact condition. Although the instrument had been retracted, the rover's software interpreted this as an unexpected collision of the spectrometer with an object, so it terminated any further arm operations. The stuck switch flipped about three minutes later but the rover is programmed to wait until the false error is cleared by mission control.

On sol 85, Spirit will retake microscope images of areas on Mazatzal, and overnight Mössbauer and alpha particle X-ray spectrometer integrations will be repeated.


sol 81, Mar 26, 2004: Rats in "New York"

Spirit began sol 81, which ended at 11:02 a.m. PST on March 26, 2004, by stopping the alpha particle X-ray spectrometer integration and then imaging the instrument's placement with the hazard avoidance camera. The rest of this sol was all about grinding into the target "New York" on the rock named "Mazatzal."

The rock abrasion tool operated on the New York target for three hours and forty-five minutes and created an impression in the rock that was 3.79 millimeters (.15 inches) deep. The angular shape of Mazatzal and the fact that the rock is a little harder than previously abraded rocks allowed the more flat side of the circular target to receive a more intense grind. On sol 83, the science and engineering teams plan to again place Spirit's rock abrasion tool onto the rock, overlapping the already abraded area and reaching the area just to the left.

Spirit will spend most of sol 82, which will end at 11:42 a.m. PST on March 27, 2004, analyzing the rock abrasion tool impression with the microscopic imager, Mössbauer spectrometer and alpha particle X-ray spectrometer. The rover will also place the microscopic imager over a clean surface to the upper left of the ratted area and take some images.

The wake-up song today was "Boy from New York City" by The Manhattan Transfer, in honor of the grind on the New York target.

Spirit's odometer now reads: 492 meters - more than a quarter of a mile!


sol 80, Mar 25, 2004: Open the Door

On sol 80, which ended at 10:23 a.m. PST on March 25, NASA's Mars Exploration Rover Spirit repeated overnight measurements of "Illinois" and "New York," two targets on the rock "Mazatzal." The measurements needed to be repeated because the alpha particle X-ray spectrometer's doors inadvertently did not open during the prior sol. In honor of doors being stuck partially open, sol 80's wake up song was "Open the Door" by Otis Redding.

Mazatzal is one of an apparent class of "light-toned rocks," which may be common in the area where Spirit landed in Gusev. This rock appears to be a "ventifact," which means it may have been carved by the steady winds that scientists know come from the northwest into the top area of this crater rim.

The plan for sol 81, which will end at 11:02 a.m. on March 26 PST, is to grind into Mazatzal with the rock abrasion tool.


sol 79, Mar 24, 2004: Sweep and Study the 'States'

NASA's Mars Exploration Rover Spirit awakened at 9:35 a.m. Mars Local Solar Time on Sol 79, which ended at 9:43 a.m. PST on March 24. An early morning review of the alpha particle X-ray spectrometer data revealed that the instrument's doors were not fully open and that the tool did not completely engage at the intended "New York" target on the rock dubbed "Mazatzal." The alpha particle X-ray spectrometer integration on "New York" will be repeated on sol 80.

Spirit took a nap until 12:45 Mars Local Solar time to conserve power for the upcoming grind on Mazatzal on sol 81. Once the rover woke up, it began the sequences of brushing and analyzing two targets, "New York" and "Illinois," on Mazatzal. Each target was brushed with the rock abrasion tool and then imaged with the microscopic imager and panoramic camera. The entire sequence ended with a Mössbauer spectrometer integration on the New York target.

Rover controllers plan to let Spirit rest until 4 a.m. Mars Local Solar time on Sol 80, when the tools on the robotic arm will be changed to place the alpha particle X-ray spectrometer on the brushed New York target. The rest of sol 80, which will end at 10:23 a.m. on March 25, will be spent analyzing the brushed and unbrushed areas of Mazatzal with the instruments on the rover's robotic arm.


sol 78, Mar 23, 2004: Preparing to Grind at Mazatzal

NASA's Mars Exploration Rover Spirit woke up at 7:24 a.m. Mars Local Solar time on sol 78, which ended at 9:04 a.m. on March 23, 2004, and began a day of observations in preparation for the sol 79 grind on the rock called "Mazatzal."

After waking, Spirit warmed-up the mast actuators for some early morning soil and atmosphere miniature thermal emission spectrometer observations. It then went back to sleep before beginning the morning direct-to-earth communication session with the high gain antenna.

At 10:00 a.m. Mars Local Solar time, Spirit began analyzing the soil targets "Saber" and "Sandbox" with the mini thermal emission spectrometer. It also took panoramic camera images of "Skull" and Saber. Then it was time to unfold the instrument arm to capture microscopic imager images of three targets on Mazatzal: "Arizona," "Illinois," and "New York." The New York target was further analyzed with a 17-hour Mössbauer spectrometer integration.

While the Mössbauer was integrating, Spirit proceeded to execute several mini thermal emission spectrometer and panoramic camera observations of interesting features in the surrounding area. The observations included images of "Bonneville" crater, "Saber," "Sandbox" and "Orange Beach."

Spirit had completed all these activities by 2:40 p.m. Mars Local Solar time and then took a siesta until the afternoon Odyssey UHF pass. During that pass, the rover captured mini thermal emission spectrometer ground and sky images. Before shutting down at 5 p.m. Mars Local Solar time, Spirit positioned the panoramic camera for a nighttime observation of the moon Deimos.

Sol 79, which ends at 9:43 a.m. on March 24, 2004, will be a momentous day for Spirit's rock abrasion tool; it will complete brushings on two Mazatzal targets.


sol 77, Mar 22, 2004: One Step Closer

Spirit woke up on sol 77, which ended at 8:24 a.m. PST on March 22, 2004, to "One Step Closer" by the Doobie Brothers, since the rover was to make its final approach to the rock target named "Mazatzal" today.

Before beginning the .9-meter (2.95 feet) drive to Mazatzal, Spirit analyzed the soil target "Soil 1" at its current location with the microscopic imager and Mössbauer spectrometer. During the Mössbauer integration, Spirit also took panoramic camera images and performed miniature thermal emission spectrometer analysis of the atmosphere and Mazatzal work area.

At 1:25 p.m. Mars Local Solar Time, Spirit completed the Mössbauer integration, took a few microscopic imager images of the impression left on "Soil 1" by the Mössbauer spectrometer and then stowed the instrument arm. Spirit then proceeded the short distance toward Mazatzal and took hazard avoidance camera images to confirm that its final resting place put the intended rock targets in reach of the instrument arm.

Following the drive, the rover acquired more panoramic camera and mini thermal emission spectrometer observations of the atmosphere, and of interesting areas near the Mazatzal site including targets named "Sandbox," "Saber" and "Darksands."

Spirit finished up sol 77 by getting the mini thermal emission spectrometer in position for morning observations on sol 78.

Spirit will spend most of Sol 78, which will end at 9:04 a.m. PST on March 23, analyzing Mazatzal with the instruments on the robotic arm.


sol 74, Mar 19, 2004: 'Stub Toes' Won't Stop Spirit

Spirit began the morning of Sol 74, which ended at 6:25 a.m. PST on March 19, 2004, by completing an alpha particle X-ray spectrometer integration on the target "Panda," inside the scuff on "Serpent" drift. Then Spirit placed the alpha particle X-ray spectrometer back down on the target "Polar" for a 30-minute integration. During that integration, Spirit took some images of disturbed soil with the panoramic camera, and acquired some ground temperatures with the miniature thermal emission spectrometer. Spirit then switched the tools on its robotic arm to the Mössbauer spectrometer for an hour-long integration on Polar. During that integration, the rover took some sky and ground measurements with the mini thermal emission spectrometer. Spirit finished its arm activities for the day by acquiring three microscopic images of Polar and three more of Panda.

Starting around 12:35 p.m. Mars Local Solar time, Spirit made a direct drive of about six meters (19.7 feet) to another section of the Serpent drift complex, called "Stub Toe." There the rover repeatedly scuffed the drift and advanced .15 meters (half a foot) in a series of five "scuff and drives." After the five scuffs and advances were made, Spirit roved forward another 3 meters (9.8 feet) and then looked back over its shoulder using the mini thermal emission spectrometer and navigation cameras to analyze the damage. The rover continued along the Bonneville crater rim with a 16-meter direct drive, and then an auto-navigation drive for 9 meters (29.5 feet). Spirit completed a final set of drives to set up for a touch and go on sol 75 at around 2:10 p.m. Mars Local Solar time. The total amount of driving for sol 74 was an impressive 34.3 meters (112.5 feet).

Spirit then took navigation camera and panoramic camera images of the drive directions for planning the sol 75 traverse. The rover acquired some mini thermal emission spectrometer reconnaissance images and then took a 30-minute siesta before the afternoon Odyssey relay pass. During that pass, Spirit used the mini thermal emission spectrometer to acquire a sky profile and ground temperature observations.

On sol 75, which will end at 7:05 a.m. PST on March 20, 2004, Spirit will place the microscopic imager on a soil target and drive about 22 meters (72.2 feet) around the Bonneville crater rim. Spirit will also conduct atmospheric observations with the mini thermal emission spectrometer and panoramic camera.


sol 73, Mar 18, 2004: A Close-Up of 'Serpent'

Spirit spent most of sol 73, which ended at 5:46 a.m. PST on March 18, 2004, analyzing targets in the drift dubbed "serpent" with the microscopic imager. But before the close-ups began, Spirit acquired miniature thermal emission spectrometer inertia measurements on a disturbed area of soil. It also caputred panoramic camera images of the scuffed area, dubbed "Bear Paw," the wheel that did the digging, and a nearby rock target named "White Elephant."

The microscopic imager work began at 11:00 am Mars Local Solar Time and was targeted at four points within the scuffed area on Serpent. The targets were given the bear-type names of Polar, Spectacled, Kodiak and Panda. For each target, seven microscopic images were taken to assure proper focus. At the Spectacled and Kodiak targets, a microscopic image with the filter in place was also taken for pseudo-color. Then the Mössbauer was placed on Panda and started an overnight integration. The arm activities were completed by about noon Mars Local Solar time, and were followed by the second thermal inertia measurement on the disturbed soil.

The rover took a siesta until 1:00 p.m. Mars Local Solar time, and then woke up for a series of mini thermal emission spectrometer observations on the rocks named "White Elephant," "Fruitcake," and "Dihedral." Then the third and last thermal inertia measurement was taken on the disturbed soil.

Spirit took another quick nap in the afternoon, and then completed sky measurements with the mini thermal emission spectrometer and panoramic camera.

Spirit will have an early start on sol 74, which will end at 6:25 a.m. PST March 19, 2004. Sol 74 will include a tool change to the alpha particle X-ray spectrometer and the beginning of an integration on the drift target named Panda. Before the sol is over, Spirit will also analyze an undisturbed area of the Serpent drift before continuing to drive around the rim of "Bonneville" crater.


sol 72, Mar 17, 2004: Spirit Digs with a Jig

Sol 72, which ended at 5:06 a.m. PST on March 17, was a day full of digging for NASA's Mars Exploration Rover Spirit. Spirit began the day taking panoramic camera and miniature thermal emission spectrometer observations of the drift dubbed "Serpent" before creating the "scuff" that would reveal the inside material at this location.

Then it was time to get into position. The rover drove about two-and-a-half meters (8.2 feet) to put the left front wheel up onto the drift. It then turned right and left five degrees to dig the left front wheel into the drift. When the "shimmy" was complete, Spirit backed 10 centimeters (3.9 inches) out of the hole. The digging and backing process was repeated four times to thoroughly scuff Serpent's side. Then Spirit backed up another meter (3.28 feet) to attain miniature thermal emission spectrometer, panoramic camera and navigation camera observations of the scuffed area. These observations will aid in in-situ target selection. To prepare for the upcoming in-situ work, Spirit drove forward 0.4 meters (1.3 feet) for additional imaging, and then drove forward a final 0.45 meters (1.5 feet) to put the scuff in the arm work volume.

Spirit spent the rest of the day obtaining navigation camera and panoramic camera observations of the intended drive direction around part of the crater rim. Spirit will do some work overnight, taking miniature thermal emission spectrometer thermal inertia and atmosphere measurements.

On sol 73, which will end at 5:46 a.m. PST on March 18, Spirit will conduct extensive microscopic imaging of sections of the drift, and run an overnight Mössbauer and alpha particle X-ray spectrometer integration.


sol 71, Mar 16, 2004: Steering to 'Serpent'

Spirit began sol 71, which ended at 4:26 a.m. PST March 16, 2004, with a morning nap to re-charge after the record-breaking number of activities it accomplished on sol 70. After that, it was back to work. Spirit began by retracting the alpha particle X-ray spectrometer, closing the doors, and imaging the doors with the front hazard avoidance cameras to confirm that they were closed. Spirit then proceeded to observe a soil target with the microscopic imager, and it also used the panoramic camera to observe the magnets, do a sky survey and capture a dust devil movie.

Then it was time to drive. Spirit completed a 15-meter (49.2 feet) blind drive followed by a 3-meter (9.8 feet) auto-navigation drive around the south rim of "Bonneville" crater toward a drift named "Serpent." Once there, Spirit completed post-drive science observations and a miniature thermal emission spectrometer study of the atmosphere, ground and future drive direction.

Spirit's main objective on sol 72, which ends at 5:06 a.m. PST March 17, 2004, will be to disturb and analyze the material at Serpent. Spirit will drive over the dune and back up to an optimal observation position. It will then analyze the area with the panoramic camera and mini thermal emission spectrometer. Spirit will end the sol by driving back on top of the dune.


sol 70, Mar 15, 2004: Spirit's Busiest Day

Spirit began what would be a very busy sol 70, which ended at 3:47 a.m. PST March 15, by analyzing a soil target dubbed "Gobi 1" with the Mössbauer spectrometer. This was the first of 43 observations that Spirit would complete on sol 70, breaking the previous observation record of 31 observations in one sol.

After the successful Mössbauer integration, Spirit took panoramic camera images of the sky. Then the miniature thermal emission spectrometer analyzed rock and soil targets. Following this, Spirit turned its panoramic camera and miniature thermal emission spectrometer to a range surface and atmospheric observations. Before the sol ended, Spirit also took microscopic images of the Mössbauer footprint left on the soil target and switched instruments to the alpha particle X-ray spectrometer for a long integration starting early on sol 71 at the "Gobi 1" location.

Spirit will spend Sol 71, which will end at 4:26 a.m. PST March 16, completing the alpha particle X-ray spectrometer analysis, taking panoramic camera images and microscopic imager images of the area, and then driving 15 meters (49.2 feet) to a location dubbed "Serpent Dune" in the afternoon.


sol 69, Mar 14, 2004: New Panorama on Board

During its 69th sol on Mars, ending at 3:07 a.m. Sunday, PST, NASA's Spirit finished shooting frames with its panoramic camera for a full 360-degree color view of the surroundings visible from the crater rim where the rover is perched. Once the panorama frames are transmitted to Earth, scientists will use them and information from Spirit's miniature thermal emission spectrometer to assess the structures and composition of the crater interior and other surfaces in view.

Spirit did not move from its vantage point on the south rim of the crater nicknamed "Bonneville." An extra downlink session was added via relay by NASA's Mars Odyssey orbiter to accelerate getting the panoramic imaging data to Earth. The total amount of data received from Spirit during the sol through relays and direct-to-Earth transmission was 225 megabits.

In the martian afternoon, Spirit added a set of observations with the miniature thermal emission spectrometer in coordination with overhead passage of NASA's Mars Global Surveyor orbiter, which carries a similar spectrometer looking down. Events of the sol also included two camera sessions requested by engineers. The first was to get high-resolution images of Spirit's heat shield on the northern rim of "Bonneville." The other was to photograph wheel tracks to help rover mobility specialists assess slippage. For sol 69's wake-up music, the team spun John Lennon's "Watching the Wheels."

Plans for sol 70, ending at 3:47 a.m. Monday, PST, feature more remote sensing from the rover's current location, before a drive along the rim begins on sol 71.


sol 68, Mar 13, 2004: Spirit Sits Still for Science

Spirit spent all of sol 68, which ended at 2:28 a.m. PST on March 13, 2004, at the "Bonneville" crater location. It began the morning operating the panoramic camera to acquire the first images of what will be a 360-degree shot of "Bonneville's" rim and basin, and the "Columbia Hills" to the southeast.

Spirit also moved the instrument deployment device, or rover arm, into position to acquire panoramic camera images of the magnets on the rock abrasion tool. It then placed the Mössbauer spectrometer on soil for a short integration after taking five microscopic imager images.

Around 13:35 Mars Local Solar time, one of Mars' moons, Deimos, passed in front of the sun. Scientists and rover controllers took this opportunity to image the moon's transit with the panoramic camera before completing mini thermal emission spectrometer observations of the crater interior.

Spirit's work isn't over though. The Mössbauer will continue analyzing the soil at "Bonneville's" rim through the night.

Sol 69, which will end at 3:07 a.m. PST on March 14, 2004, will also be a no-drive sol during which Spirit will acquire the second half of the 360-degree panoramic camera image of Bonneville. Spirit will also perform remote sensing of the inside of the crater and analyze soil targets with the Mössbauer and alpha particle x-ray spectrometer.


sol 67, Mar 11, 2004: Spirit is "On Top of the World"

Spirit woke up on sol 67, which ended at 1:48 a.m. PST March 12, 2004, to "On Top of the World" by the Carpenters. The song was fitting, as yestersols's drive put Spirit at the rim of "Bonneville" crater, but it took some additional maneuvering to get the rover perfectly placed for the 360-degree panoramic camera images it will take on upcoming sols.

Before beginning the sol 67 drive, Spirit completed an overnight alpha particle x-ray spectrometer integration and a couple of small panoramic camera shots of its surroundings.

Then the rover traveled 13 meters (42.7 feet) in a direct drive around some obstacles followed by a 1.4-meter (4.6 feet) automatic navigation drive. Spirit spent the afternoon using the mini thermal emission spectrometer to look at targets that will be analyzed more fully on sol 67, and then driving 0.9 meters (3 feet) forward to be able to access that area with the arm tomorrow.

Spirit put a total of 24.8 meters (81.4 feet) on the odometer today, partly due to some back and forth maneuvering it had to do to ensure a safe path. The final location has proven to be just right, and Spirit will stay put for a couple sols while it continues to investigate "Bonneville" crater.

Before the day was over, Spirit looked at the sun for an attitude update and then took front hazard avoidance camera images of the arm work volume, and a small navigation panorama of the crater. The rover also completed some mini thermal emission spectrometer analysis of the far side of the crater and finished the day with some panoramic camera images of the sunset.

On sol 68, which will end at 2:28 a.m. PST March 13, 2004, Spirit will begin a two-sol panoramic camera session and complete selected mini thermal emission spectrometer observations. The rover will also begin a very long Mössbauer integration on a soil target.


sol 66, Mar 11, 2004: Spirit is "Livin' on the Edge"

Aerosmith wrote the song "Livin' on the Edge" long before Spirit reached the edge of Bonneville crater, and probably never imagined it would be the wake-up song for a rover on Mars. But its words are appropriate. After a 21-meter (68.9 feet) drive and an elevation gain of 1.5 meters (4.9 feet), Spirit is in fact at the edge of Bonneville crater.

Spirit began Sol 66, which ended at 1:09 a.m. PST March 11, 2004, by taking a look back at the lander with the panoramic camera, and then analyzing selected ground targets. At about 11:30 a.m. Gusev time, Spirit began a 30-minute directed drive of 16 meters (52.5 feet). It then turned right for a final auto-navigation drive that was intended for 6 meters (19.7 feet), but resulted in about 4 meters (13.1 feet). That drive put Spirit in perfect position to look inside "Bonneville" crater and send back stunning images from the navigation camera.

The camera mast was then positioned for a nighttime sky observation of the Orion Constellation. During NASA's Mars Global Surveyor pass tomorrow morning, the navigation camera and panoramic camera will take images of the Orion Constellation using long exposure times.

On Sol 67, which will end at 1:48 a.m. PST March 12, 2004, Spirit will drive about 14 meters (46 feet) to a better vantage point on the crater rim and continue to investigate Bonneville with the panoramic and navigation cameras.


sol 65, Mar 10, 2004: Roving Toward the Rim

Spirit spent sol 65, which ended at 12:29 a.m. PST on March 10, analyzing soil targets with the alpha particle x-ray spectrometer, Mössbauer spectrometer and microscopic imager before stowing its arm, doing some remote sensing of the trench dubbed "Serendipity Trench," and then finally setting off for the longest directed drive to date. That drive was 27 meters (88.6 feet) toward the edge of "Bonneville" crater.

Spirit then attempted to use auto navigation to reach a target that was an additional 6 meters (19.7 feet) away. Sensitive obstacle avoidance software prevented Spirit from reaching the destination, and like yestersol, the rover completed several drives forward and back. Those drives resulted in a final odometer reading of 40.7 meters (133.5 feet) for the day, even though the total straight-line distance traveled was 30 meters (98.4 feet).

The 30-meter (98.4 feet) drive put Spirit close enough to "Bonneville's" edge to take images with the navigation cameras that reveal the opposite rim of the crater.

On sol 66, which ends at 1:09 a.m. PST on March 11, 2004, Spirit will drive up to the summit of the rim and show us what's inside with a 180-degree navigation camera panorama.


sol 64, Mar 08, 2004: Spirit Reaches the 300-Meter Mark!

Spirit completed another 29 meters (94 feet) of its drive toward the rim of "Bonneville" crater on sol 64, which ended at 11:49 p.m. PST, bringing its total odometry to 314 meters (1,030 feet) - 14 meters (45.9 feet) past the minimum mission success criterion.

Spirit began the morning with an 18-meter (59 feet) direct drive that safely maneuvered the rover through a field of rocks. Spirit then traversed 11 more meters (35 feet) using autonomous navigation and at 11:30 a.m. Mars Local Solar Time completed the drive. Spirit had some difficulty finding a way around an obstacle during the last portion of the commanded drive. That resulted in some repeated forward and backward maneuvering which left an interesting "trench" for scientists to have the rover peer into.

Spirit is climbing up a very steep part of "Bonneville" now, and ended this sol's drive tilted at a forward pitch of about 15°.

For the next sol, the plan was to have Spirit perform some mini-thermal emission spectrometer sky and ground observations before waking up to do a touch-and-go and drive again!


sol 62, Mar 07, 2004: Rolling Along

During its 62nd sol on Mars, ending at 10:30 p.m. Saturday, PST, NASA's Spirit advanced about one-fifth of the remaining distance between where it began the sol and its mid-term destination, the rim of the crater nicknamed "Bonneville." In the martian afternoon, Spirit took images and infrared readings of the area right in front of its stopping place to support the following morning's close-up inspection of that new location with instruments on the rover's robotic arm.

Spirit drove 26.15 meters (85.8 feet) on sol 62, bringing its odometer total to 250.71 meters (822.5 feet). Some of the drive maneuvered around obstacles. The net gain in the northeasterly direction toward the crater rim was 22 meters (72 feet), and that destination was estimated to be about 88 meters (289 feet) away from Spirit's new location. The miniature thermal emission spectrometer was used for ground and sky observations both before and after the drive.

The wake-up song for the sol was "My First Trip to Mars," by Atticus Fault.

For sol 62, ending at 11:10 p.m. Sunday, PST, Spirit's agenda is to drive on toward the crater rim after using the microscope and spectrometers on its arm to inspect the site where it wakes up.


sol 61, Mar 06, 2004: Leaving Middle Ground

After more than a week of camping and field work at "Middle Ground," NASA's Spirit took a few last pictures from there then drove onward to the northeast on sol 61, which ended at 9:51 p.m. Friday, PST. In the martian morning, Spirit's panoramic camera took the final frames needed for the camera team to assemble a full-circle color panorama after all the data reaches Earth.

In the early afternoon, Spirit backed up 0.5 meter (20 inches), then edged forward 0.29 meters (11 inches) to sidestep a rock called "Ingrid." Then the rover advanced 28.5 meters (94 feet) toward its crater-rim destination. The drive took 45 minutes. From the new location, Spirit took forward-looking pictures for use in future drive planning. It also observed the ground and the sky with its miniature thermal emission spectrometer.

For the sol's theme tune in the morning, controllers at JPL played "Motor Away" by Guided by Voices.

Continued driving toward the crater nicknamed "Bonneville" is the plan for Spirit's 62nd sol, ending at 10:30 p.m. Saturday, PST.


sol 60, Mar 04, 2004: Ready to Hit the Road Again

Spirit completed its observations at "Middle Ground" on its 60th martian sol, ending at 9:11 p.m., PST on March 4. Waking up to "Pictures to Prove It," by the Mighty Mighty Bosstones, Spirit finished gathering data from the rock abrasion tool hole on "Humphrey" with the alpha particle X-ray spectrometer and the microscopic imager.

The panoramic camera then continued to acquire more images for the 360-degree view from the current rover position at "Middle Ground."

After backing up 0.85 meters (about 2.8 feet), the miniature thermal emission spectrometer and panoramic camera had their turn to collect data and images from both of the rock abrasion tool's latest efforts on "Humphrey" - the triple-brushed area and the depression.

As of this sol, Spirit has traveled 195.24 meters (about 641 feet).

Plans for next sol include backing up and turning to avoid "Ingrid," a 20-centimeter (about 8 inches) rock to the west of "Humphrey," and then driving approximately 25 meters (82 feet) toward "Bonneville" in the northeast. Spirit will also snap the final images that will make up the 360-degree panorama of "Middle Ground."


sol 59, Mar 03, 2004: Rock Abrasion Tool Back in Action

Waking up to "One More Time" by The Real McCoy, Spirit completed a successful, 2 millimeter-deep grind (.08 inches) into a target slightly left of the depression it made yestersol during its abbreviated operation. A five-minute brush to clean the hole followed.

Completing the sol, which ended at 8:31 p.m. Wednesday, March 03, Spirit's arm then switched instruments so the Mössbauer spectrometer could examine "Humphrey's" new shallow cavity.

Before this sol's four-hour grinding, the microscopic imager and the alpha particle X-ray spectrometer finished observations of yestersol's rock abrasion tool depression. To document Spirit's current position - about halfway to the "Bonneville" crater rim - the panoramic camera snapped the first of several images that, together, will provide a 360-degree view.

Engineers identified the software issue that caused the rock abrasion tool to terminate its original planned grinding on sol 58. The minor bug will be fixed when new flight software is loaded at the end of March.

In the coming sols, Spirit will complete the alpha particle X-ray spectrometer observations of the rock abrasion tool hole and get an up-close view with the microscopic imager. The final images will be obtained for the full panoramic view of Spirit's current position. After miniature thermal emission spectrometer and panoramic camera observations of the hole are conducted, Spirit will continue on toward "Bonneville" crater.


sol 58, Mar 02, 2004: Grinding, Take Two

On sol 58, which ends at 7:52 p.m., PST on March 2, the planned four-hour rock abrasion tool grind of "Humphrey" was limited to only 20 minutes. The intricate slopes and cracks of the rock make it a challenging target for instruments. When sensors indicated a loss of contact with surface material, the software perceived a problem and the rock abrasion tool was moved away from the rock. Engineers are amending the software limits to duplicate the rock abrasion tool's earlier operation on the rock "Adirondack," giving a higher likelihood of successful completion on the next sol.

The morning began with the completion of the alpha particle X-ray spectrometer integration on the previously brushed area. The panoramic camera then took a multi-spectral observation of the nearby ground, followed by a Mössbauer spectrometer integration on the same area.

Spirit's Sol 58 wake-up song was "I Still Haven't Found What I'm Looking For" by U2 to pay homage to its twin rover's amazing findings of water evidence at Meridiani Planum.

On sol 59, Spirit will attempt another rock abrasion tool grind on "Humphrey," followed by detailed observations of the hole.


sol 57, Mar 01, 2004: Back to the Ol' Grind

During its 57th sol on Mars, ending at 7:12 PST on March 1, Spirit observed the area on "Humphrey" that was thrice brushed by the rock abrasion tool. An area just to the right of the brushed area, where the team intends to grind, was also examined.

The morning hours found Spirit using its alpha particle X-ray spectrometer on the intended grinding target to verify its similarity to the pre-brushed areas of the rock. The arm then switched out tools to the microscopic imager to get close-up views of the grinding target and the area to the right of it. The Mössbauer spectrometer was then placed on the brushed area for another observation.

Panoramic camera images were taken of the rock abrasion tool magnets to study dust accumulation. The miniature thermal emission spectrometer performed a diurnal characterization on the nearby soil. This allows scientists to look at the temperature difference from day to night, revealing information about particle sizes within the soil.

Next sol, the plan calls for Spirit to grind into "Humphrey" and then use its arsenal of instruments to analyze the interior of the rock.


sol 56, Mar 01, 2004: Grooming for the Grind

On sol 56, which ended at 6:33 p.m. PST, February 29, Spirit completed the .55-meter (1.8 feet) re-approach to "Humphrey" to get into position for grinding with the rock abrasion tool. After the repositioning, the rover took panoramic camera and miniature thermal emission spectrometer data of its rear tracks and the path in front of it, leading the way to "Bonneville" crater.

The wake-up song for the sol was "Walking On Sunshine," performed by Jump 5.

In the coming sols, Spirit will use its rock abrasion tool to grind into "Humphrey," observe the results with the instruments on its arm, and then continue on toward "Bonneville."


sol 55, Feb 29, 2004: Brush, Brush, Brush, Then Step Back

Spirit used its rock abrasion tool for brushing the dust off three patches of a rock called "Humphrey," during its 55th sol on Mars, ending at 5:53 p.m. Saturday, PST. Before applying the wire-bristled brush, the rover inspected the surface of the rock with its microscope and with its alpha particle X-ray spectrometer, which identifies elements that are present. Brushing three different places on a rock one right after another was an unprecedented use of the rock abrasion tool, designed to provide a larger cleaned area for examining.

Afterwards, Spirit rolled backward 85 centimeters (2.8 feet) to a position from which it could use its miniature thermal emission spectrometer on the cleaned areas for assessing what minerals are present. Due to caution about potential hazards while re-approaching "Humphrey," the rover moved only part of the way back. Plans for sol 56, ending at 6:33 p.m. Sunday, PST, call for finishing that re-approach and further inspecting the brushed areas. If all goes well, the rock abrasion tool's diamond-toothed grinding wheel will cut into the rock on sol 57 to expose fresh interior material.

For wake-up music on sol 55, controllers chose "Brush Your Teeth," by Cathy Fink and Marcy Marxer, and "Knock Three Times," by Tony Orlando and Dawn.


sol 54, Feb 27, 2004: Heading To "Humphrey"

On sol 54, Spirit woke up to the song "Big Rock in the Road" by Pete Wernick and made its final approach to the imposing rock called "Humphrey" before the sol ended at 5:13 p.m. PST on Friday, Feb. 27. The initial 3.5 meter (11.5 feet) drive toward the rock was cut short at only 2.5 meters (8.2 feet) due to a built-in software safety. Rover engineers quickly adjusted the software restriction and drove the final meter of that planned drive, plus the 0.9 meters (about 3 feet) that put the rover in the best position for brushing "Humphrey" with the rock abrasion tool.

Before approaching the rock, Spirit used its alpha particle X-ray spectrometer to investigate the areas the rock abrasion tool will brush and grind. Unlike the last rock abrasion tool sequence on the rock called "Adirondack," the planned procedure for "Humphrey" will include brushing three separate areas of the rock. After brushing, Spirit will back up and examine the brushed areas with the instruments on its arm. The science team will then decide the best place to grind into "Humphrey" - it could be one of the three brushed areas or another section altogether. The hope is to remove as much dust as possible so the instruments on Spirit's arm can get a pre-grinding "read" on the rock coating and then, after grinding, study beneath the coating and surface.

In the sols following the rock abrasion tool sequence, Spirit might investigate an interesting rock behind it, or continue on toward "Bonneville" crater.


sol 53, Feb 26, 2004: Eyeing Martian Dust Devils

On sol 53, which ends at 4:34 p.m. PST on February 26, Spirit woke up to the 70s ballad "Dust in the Wind" by Kansas, with the anticipation of possibly capturing dust devils spinning across the martian surface. The rear hazard avoidance camera was commanded to "roll tape" from 12:00 to 12:30 local solar time to record these so-called "mini-tornadoes." The behavior of dust devils helps scientists track the transfer of dust on the red planet.

A final, .85-meter (about 2.8 feet) drive brought Spirit to its exact target at the "Middle Ground" site. The rover also conducted an examination, using its microscopic imager and alpha particle X-ray spectrometer, of the magnet arrays that are collecting airborne dust.

In the coming sols Spirit will inspect the soil at its current position with the tools on its arm. Following that, the plans call for the rover to approach the rock called "Humphrey." After a thorough assessment of "Humphrey," the rock abrasion tool will be used to brush and then grind.


sol 52, Feb 25, 2004: Spirit Looks Back at Earth

On sol 52, which ended at 3:54 p.m. PST, February 25, rover engineers drove Spirit the short 4-meter (13.1 feet) drive to "Middle Ground" after finishing observations with the miniature thermal emission and Mössbauer spectrometers. Several stutter steps that would have put Spirit at the exact target location were not executed because they were programmed with built-in safeties. The rover detected slight hazards and stopped within its constraints. The final steps will be executed next sol.

Waking up to Foreigner's "Cold as Ice," Spirit's first job of the sol was to warm up its arm that was significantly colder than yestersol due to the rover's orientation to the northwest. The engineering team also took a moment to wave to Spirit as its panoramic camera faced and imaged Earth.

Spirit will remain at "Middle Ground" for the next several sols and continue observing targets with its spectrometers and microscopic imager. Plans also call for high-resolution images of rocks and an examination of the soil.


sol 51, Feb 24, 2004: Making Ground

To inspire a morning "run" on sol 51, which ended at 3:15 p.m. Tuesday, PST, Spirit woke up to Vangelis' "Chariots of Fire." The rover deployed its arm, took microscopic images of the soil in front of it and then proceeded toward its target, "Middle Ground." Spirit drove 30 meters (98.4 feet), breaking its own record for a single-sol traverse. Along the way, Spirit paused to image rocks on both sides of the drive path with its panoramic camera.

The auto-navigational software that drove the last 12 meters (39.4 feet) of the traverse to the "Middle Ground" target warned Spirit that the slope into the hollow that houses it was too steep (according to parameters set by rover engineers). Spirit then paced along the rim, looking for a safe way down. Unable to locate a secure path into the crater before the sol ended, Spirit ended up facing slightly west of north instead of northeast, as called for by the plan. This orientation will reduce the amount of data the rover can return (due to interference between the UHF antenna and items on the rover equipment deck), but it will be corrected in the coming sols.

As of today, Spirit has moved 183.25 meters (601.21 feet) and is now roughly 135 meters (442.91 feet) from its landing site, Columbia Memorial Station.

The intent for the next several sols will be to drive Spirit into "Middle Ground" and take a full panorama of the surrounding area to identify scientifically interesting rocks.


sol 50, Feb 23, 2004: Heading for Middle Ground

On Sol 50, ending at 2:35 p.m. PST, Spirit finished observations of the trench at "Laguna Hollow," then continued on its journey toward the crater called "Bonneville." Driving in a dog-leg pattern to avoid some bumpy terrain, Spirit traveled approximately 18.8 meters (61.7 feet) toward the halfway point, called "Middle Ground." The last 2.8 meters (9.2 feet) were covered using autonomous navigation software.

After completing the drive, Spirit gathered miniature thermal emission spectrometer data on the ground on both sides of the rover, and its panoramic camera and navigation camera took pictures.

The wake-up song this morning (Sunday evening Pacific time) was "Samba De Marte" by Beth Carvalho from her "Perolas Do Pagode" album. The lyrics include a verse about waking up the rover on Carnival Day. This song was written by Beth Carvalho after she heard that one of her songs was used to wake up Mars Pathfinder's Sojourner rover during the 1997 mission. This is quite appropriate, as this spirited sol 50 also began on Carnival day in Brazil!

In the coming sols, Spirit will complete the drive to "Middle Ground."


sol 49, Feb 22, 2004: Trench Exam Continues

Spirit continued its inspection of the trench dubbed "Road Cut" during the rover's 49th sol, ending at 1:56 p.m. Sunday, PST. It used three instruments on its robotic arm to examine the subsurface soil exposed by the sol 47 digging of the trench.

Before dawn on sol 49, Spirit switched from its Mössbauer spectrometer to its alpha particle X-ray spectrometer for analysis of soil on the trench floor. Later, controllers played "Coisinha do Pai," by Beth Carvalho, as wake-up music. The rover inspected targets on the wall and floor of the trench with its microscope, then placed the Mössbauer spectrometer against a target on the trench wall for identifying the iron-bearing minerals there. The miniature thermal emission spectrometer took remote readings on the rover's wheel tracks in the morning and afternoon.

Plans for sol 50 (ending at 2:35 p.m. Monday, PST) call for finishing inspection of the trench, then resuming the journey toward the rim of a crater dubbed "Bonneville," followed by a longer drive the following sol.


sol 48, Feb 21, 2004: Down in the Trench

On its 48th sol, ending at 1:16 p.m. Saturday, PST, Spirit maneuvered its robotic arm successfully within the challengingly tight confines of the trench that the rover had dug into the floor of "Laguna Hollow" the preceding sol.

Spirit used the microscopic imager on the arm to take pictures of details in the wall and floor of the trench during the morning. Then Spirit rotated the tool turret at the end of its arm and placed the Mössbauer spectrometer in position to read the mineral composition of the soil on the trench floor. That reading was designed to last about 12 hours, from mid-sol into the martian night. Spirit's panoramic camera and miniature thermal emission spectrometer were also used during the sol for studies of sky and rocks.

Spirit has been told to wake up and switch from the Mössbauer spectrometer to alpha particle X-ray spectrometer on the trench floor during the pre-dawn hours of the next sol. Later on sol 49 (which ends at 1:56 p.m. Sunday) and early on sol 50, plans call for using those spectrometers on the walls of the trench and making additional observations of the "Laguna Hollow" area. Then Spirit is slated to resume its trek toward the rim of the crater nicknamed "Bonneville," now estimated to be about 135 meters (443 feet) northeast of the rover's current location.


sol 47, Feb 20, 2004: Spirit Digs a Trench

On sol 47, ending at 12:36 p.m. February 20, 2004 PST, engineers woke Spirit up to the song "Dig Down Deep," by Hot Soup, and that's exactly what Spirit proceeded to do. The two-hour operation performed by Spirit's left front wheel resulted in a trench 7-8 centimeters deep (2.8 to 3.1 inches) that uncovers fresh soil and possibly ancient information.

Spirit dug this trench at "Laguna Hollow" the same way that Opportunity dug its 9-10 centimeter (3.5 to 3.9 inch) trench at Meridiani. However, because the ground at this location is harder, Spirit had to dig for twice as long as Opportunity - going back and forth over the surface 11 times instead of 6.

After the trench was completed, Spirit backed up one meter, or more than a yard, and analyzed the area with the miniature thermal emission spectrometer before driving forward 0.4 meters (15.7 inches) and imaging the excavation site with the panoramic camera. A final move forward of another 0.4 meters allowed Spirit to take front hazard avoidance camera images of the arm work volume which was then centered on the trench.

After stowing the arm, the rover did a series of miniature thermal emission spectrometer observations of several nearby rocks, "Buffalo," "Cherry," "Cotton," and "Jiminy Cricket," and a combined miniature thermal emission spectrometer and panoramic camera observation of "Beacon." Spirit also took panoramic camera images of its deck to observe dust accumulation on the instrumented solar cells and on the miniature thermal emission spectrometer calibration target.

Spirit then took a siesta from 2 p.m. to 3:45 p.m. Mars Local Solar time and woke up for some more panoramic camera and miniature thermal emission spectrometer observations of "Beacon," and miniature thermal emission spectrometer ground and sky stares. All activities up through the afternoon pass by the Mars Odyssey orbiter were completed successfully.


sol 46, Feb 19, 2004: Halfway Through

Sol 46, completed at 11:17 a.m. February 19, 2004 PST, marks the halfway point of Spirit's primary surface mission - sols 2 through 91. Spirit began this momentous morning by doing some remote sensing of the crater rim and imaging the surrounding soil with the panoramic camera and miniature thermal emission spectrometer. After all this work, Spirit took a break with a nap lasting slightly more than an hour. After waking, Spirit continued its observations of the ground and sky with the miniature thermal emission spectrometer. At about 1:34 p.m. Mars Local Solar Time, Spirit found itself analyzing a patch of the atmosphere with the miniature thermal emission spectrometer at the same time that Mars Global Surveyor's thermal emission spectrometer was looking down through the same chunk of atmosphere. This concurrent observation will enable a more thorough understanding of martian atmospheric conditions.

Spirit's afternoon activities began at about 4:00 p.m. Mars Local Solar Time after the Mars Global Surveyor pass. Spirit was expected to take stereo microscopic images of the target "Trout" in Laguna Hollow. This is the first time the microscopic imager will take pictures at Gusev Crater without the Mössbauer instrument first touching the surface of the soil. The observation will provide pictures of undisturbed soil. After this, Spirit will perform a calibration activity by imaging a location in the sky with the microscopic imager and the navigation camera simultaneously.

Spirit's day will stretch into the night this sol with an overnight Mössbauer spectrometer integration. After a brief sleep, Spirit will wake at about 2:00 a.m. Mars Local Solar time on sol 47 to end the integration, collect the data and turn on the arm heaters. It will prepare for changing the tool from the Mössbauer to the alpha particle x-ray spectrometer, and begin observations with the new tool. Finally, the rover will leave the alpha particle x-ray spectrometer powered on and go back to sleep around 2:30 a.m. Mars Local Solar time.

On the morning of Sol 47, which will end at 11:57 a.m. February 20, 2004 PST, the plan is for Spirit to end the alpha particle x-ray observation and collect that data, and then perform some early mini-thermal emission spectrometer soil properties observations.


sol 45, Feb 18, 2004: Spirit Does a "Wheel Wiggle"

Spirit began sol 45, which ended at 11:17 a.m. February 18, 2004 PST, at its previous target, Halo, by conducting analysis with the alpha particle x-ray spectrometer, microscopic imager and Mössbauer spectrometer. Spirit also took panoramic camera images and miniature thermal emission spectrometer observations before its arm was stowed for the northeast drive toward a circular depression dubbed Laguna Hollow.

The first 19 meters of the drive toward Laguna Hollow was commanded using go-to waypoint commands with the hazard avoidance system turned off. This mode - which was used for the first time this sol - provides automatic heading correction during a blind drive. Some fine-tuning toward the target brought the total drive for this sol to 22.7 meters (74.5 feet).

After reaching Laguna Hollow, Spirit "wiggled" its wheels to disturb or scuff the fine dust-like soil at this location, which allows for more detailed observations with the instruments on the robotic arm. After adjusting position to put the disturbed soil in reach of the arm, Spirit backed up and completed a miniature thermal emission spectrometer scan of the new work area. Before the sol ended, Spirit made one more adjustment, putting it in perfect position to analyze the scuffed area beginning on sol 46

The plan for sol 46, which will end at 11:57 a.m., February 19, 2004 PST, is to conduct observations on Laguna Hollow with the instruments on the robotic arm, including some higher resolution analysis that will involve an overnight tool change.


sol 44, Feb 17, 2004: Spirit Passes 100-Meter Mark

Spirit controllers are calling sol 44 one of Spirit's most complicated and productive sols to date. Before commencing its record-breaking drive, Spirit began the sol, which ended at 10:38 a.m. February 17, 2004 PST, with an alpha particle x-ray spectrometer analysis of the soil target Ramp Flats. The analysis ran in parallel with a miniature thermal emission spectrometer observation of the martian sky. Spirit then continued observing "Ramp Flats" with the microscopic imager and Mössbauer spectrometer while operating the panoramic camera to get pictures of rocks in the distance called "V Ger" and "Broken Slate."

But this morning multi-tasking was only the beginning. After stowing the robotic arm, Spirit began a north-northeast drive that added a total of 21.6 meters (70.9 feet), bringing the rover's grand total to 108 meters (354 feet). That distance is about 6 meters (19.7 feet) more than Sojourner's mission record, set in 1997. Controllers remarked that Spirit's auto-navigation drives are consistently getting faster. These long drives are revealing new and interesting terrain, including more ridges, dunes, ripples and rocks with various appearances.

The plan for sol 45, which will end at 11:17 a.m. Feb. 18, 2004 PST, begins with analysis of a target at the current location, followed by a drive into a hollow between 15 meters (49 feet) and 18 meters (59 feet) away.


sol 43, Feb 16, 2004: Mega Drive

Spirit spent the wee morning hours of sol 43 gathering data about a wheel-track target with the Mössbauer spectrometer, then tucked its arm and drove. It used a two-session method engineers call a "mega drive" in order to make good progress toward the crater nicknamed "Bonneville." The first driving session covered 19 meters (62.3 feet) after long-running morning activities shortened the time for driving. After a rest, Spirit continued another 8.5 meters (27.9 feet) in the afternoon, resulting in a total drive of 27.5 meters (90.2 feet), a new one-sol record. Sol 43 ended at 9:58 a.m. Monday, PST. The remaining distance to "Bonneville" is about 245 meters (about 800 feet) from Spirit's new location.

For sol 44, which will end at 10:38 a.m. Tuesday, PST, controllers plan "touch-and-go" activities: deploying the arm on a target called "Ramp Flats" before continuing toward Bonneville.


sol 42, Feb 15, 2004: A Wayside Stop, Then Back to Driving

Spirit used instruments on its robotic arm to examine an unusual-looking rock called "Mimi" during the rover's 42nd sol on Mars, which ended at 9:15 a.m. Sunday, PST. Scientists will be examining images and spectra to understand this rock's structure and composition and what those can tell about the environment in which the rock formed.

For sol 43, which will end at 9:58 a.m. Monday, PST, controllers have planned what they are calling a "mega drive": commanding a morning drive of about 25 meters (82 feet), then taking pictures of the scene ahead and letting the rover have a brief rest before using those mid-day pictures to guide an optional afternoon drive. Spirit is currently about 270 meters from the crater nicknamed "Bonneville," its mid-term destination.


sol 41, Feb 14, 2004: Spirit Gets the Drift

On its 41st sol, which ended at 8:39 a.m. Saturday, PST, Spirit examined the crest and trough of a drift formation encountered on its journey, then moved to a nearby rock.

The rover used its microscopic imager, Mössbauer spectrometer and alpha particle X-ray spectrometer on the drift material. Then it backed up about 10 centimeters (4 inches), turned, and advanced about the same distance to be in position for thoroughly examining the flaky rock called "Mimi" during sol 42, which will end at 9:18 a.m. Sunday, PST.

Plans call for resuming long daily drives on sol 43 toward the crater nicknamed "Bonneville" on the northeastern horizon.


sol 40, Feb 13, 2004: Movin' Towards "Mimi"

Spirit woke up to its 40th sol on Mars to the song "What a Wonderful World" by Louis Armstrong and then proceeded to have a wonderful sol which ended at 7:59 a.m. Friday, PST. After utilizing the miniature thermal emission spectrometer instrument on surrounding soil and completing some pre-drive imaging with the panoramic camera, Spirit proceeded 90 centimeters (2.95 feet) towards a collection of rocks called "Stone Council." The drive lasted less than five minutes. After completing the drive, Spirit imaged several rocks with the panoramic camera, and completed a mosaic of the area in front and to the left of itself.

On sol 41, which will end at 8:39 a.m. Saturday, PST, Spirit will be repositioned in front of the flaky rock called "Mimi" in preparation for placing its instrument deployment device on that rock during sol 42.


sol 39, Feb 12, 2004: New driving record

During its 39th sol on Mars, which ended at 7:20 a.m. Thursday, PST, Spirit broke its own driving record. It adding 24.4 meters (80 feet) to its odometer while getting near an interesting set of rocks dubbed "Stone Council." The drive lasted 2 hours, 48 minutes. While navigating itself to avoid hazards, Spirit stopped when it recognized an obstacle, which was the group of rocks that was the day's intended destination.

The flight team at JPL chose Buster Poindexter's version of "Hit the Road Jack," as Spirit's wake-up music. The day's commands were uplinked during the cool morning hours via Spirit's low-gain antenna, to bypass a problem diagnosed the preceding day as shade slowing the warm-up of motors that move the high-gain antenna.

Before rolling, Spirit took images with its microscopic imager and panoramic camera from the site where it started the day.

The plan for sol 40, which will end at 7:59 a.m. Friday, PST, is a short drive forward then using instruments on the robotic arm to study soil at Stone Council.


sol 38, Feb 11, 2004: It's Cold in the Shadow

On Spirit's sol 38, which ended at 6:40 a.m. Wednesday, PST, a failure to receive data during the morning high-gain communication window quickly led engineers to conclude that Spirit’s high-gain antenna was not pointed toward Earth. Spirit’s orientation after the previous sol's drive (45 degrees to the northeast) caused its camera mast to cast an early-morning shadow on the high-gain antenna’s elevation actuator. The cold conditions caused the actuator to stall and fail to point to Earth while being calibrated. The afternoon high-gain communication session performed flawlessly.

The afternoon communication window with Mars Odyssey provided previously acquired images of the rocks Adirondack and White Boat and a miniature thermal emission spectrometer observation of the depression drilled by the rock abrasion tool on Adirondack.

In coming sols Spirit will perform daily "touch and go" maneuvers, inspecting the soil surrounding it with the instruments on its arm, then continuing its drive toward the crater nicknamed "Bonneville."


sol 37, Feb 10, 2004: Record-breaking Sol

On its 37th sol on Mars, which ends at 6 a.m. Tuesday, PST, Spirit broke the record for the farthest distance driven in one sol on Mars, traveling 21.2 meters (69.6 feet). Today's distance traveled shattered the Sojourner rover's previous record of 7 meters (23 feet) in one sol.

In the coming sols, Spirit will continue its drive towards the crater nicknamed "Bonneville."


sol 36, Feb 09, 2004: Cruise Control on Mars

On sol 36, which ended at 5:21 a.m. Monday, PST, Spirit drove 6.37 meters (20.9 feet), using the onboard navigation software and hazard avoidance system for the first time on Mars. The drive, intended to test the traverse commands, was extremely precise, taking Spirit to its intended goal – the rock called White Boat. Before leaving the rock Adirondack, Spirit took images and collected miniature thermal emission spectrometer data from the hole ground by the rock abrasion tool.

In the coming sols, Spirit will continue its drive toward Bonneville Crater.


sol 35, Feb 08, 2004: Rock Interior Inspected

NASA's Spirit examined the interior of a rock during Spirit's 35th sol on Mars, which ended at 4:41 a.m. Sunday, PST. Beginning late in the previous sol, Spirit took turns placing its Mössbauer spectrometer, alpha particle X-ray spectrometer and microscopic imager over the portion of the rock called Adirondack where Spirit's rock abrasion tool had cut away the rock's surface.

Spirit did not begin driving on sol 35, because a precautionary software setting to prevent driving was still in effect from the beginning of the anomaly two weeks ago. The rover is being commanded during sol 36, which ends at 5:21 a.m. Monday, PST, to back away from Adirondack, drive past the south side of the now-empty lander, and begin a trek northeast toward a crater nicknamed "Bonneville."


sol 34, Feb 07, 2004: First Human-made Hole in a Rock on Mars…EVER!

On Spirit's sol 34, which ended at 4:02 a.m. Saturday, PST, the rover's rock abrasion tool (RAT) successfully completed history's first grind into a rock on Mars. The rock of the day was Adirondack. Scientists and engineers were ecstatic when the afternoon communications relay from Mars Odyssey revealed a round and clean-surfaced depression.

Tomorrow, on sol 35, which ends at 4:41 a.m. Sunday, PST, Spirit is being told to inspect the newly exposed ancient rock material with her Mössbauer spectrometer, microscopic imager and alpha particle x-ray spectrometer before making a six-meter (20-foot) drive around the south side of the lander.

Current plans may keep Spirit in drive mode for the next few sols as she heads northeast towards a crater nicknamed "Bonneville."


sol 33, Feb 05, 2004: First Interplanetary Brushing of a Rock!

NASA's Spirit was back and accomplishing another "first" in interplanetary science on Thursday: It brushed the dust off a rock to clean its surface for inspection.

On the first day of operations after they reformatted Spirit's flash memory, engineers confirmed that the flash memory was stable and available for data storage. Spirit was cleared to conduct the sol's science activities. The rock abrasion tool on the rover's robotic arm brushed a portion of the surface of the rock called Adirondack for five minutes. Spirit's panoramic camera and microscopic imager took pictures to show the effect of the brushing. The Mossbauer spectrometer and alpha particle X-ray spectrometer were used overnight on the brushed area.

The plan for Spirit for sol 34 is to use the rock abrasion tool again, this time to grind away the brushed portion of Adirondack's surface for examination of the rock's interior.

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