NASA Jet Propulsion Laboratory California Institute of Technology JPL HOME EARTH SOLAR SYSTEM STARS & GALAXIES SCIENCE & TECHNOLOGY JPL Email News RSS Mobile Video
Follow this link to skip to the main content
JPL banner - links to JPL and CalTech
left nav graphic Overview Science Technology The Mission People Spotlights Events Multimedia All Mars
Mars for Kids
Mars for Students
Mars for Educators
Mars for Press
+ Mars Home
+ Rovers Home
Mars for Press
Summary
Press Releases
Press Kits
Fact Sheets
Image Gallery
Press Releases

February 12, 2009

Spirit Gets Energy Boost from Cleaner Solar Panels

Very Dusty Solar Panel on Spirit, Sol 1811
NASA Mars Exploration Rover Spirit took this image using the left eye of its navigation camera during the 1,811th Martian day, or sol, of Spirit's mission on Mars (February 5, 2009).

View full images and captions
A small but important uptick in electrical output from the solar panels on NASA's Mars Exploration Rover Spirit this month indicates a beneficial Martian wind has blown away some of the dust that has accumulated on the panels.

The cleaning boosts Spirit's daily energy supply by about 30 watt-hours, to about 240 watt-hours from 210 watt-hours. The rover uses about 180 watt-hours per day for basic survival and communications, so this increase roughly doubles the amount of discretionary power for activities such as driving and using instruments. Thirty watt-hours is the amount of energy used to light a 30-watt bulb for one hour.

"We will be able to use this energy to do significantly more driving," said Colette Lohr, a rover mission manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Our drives have been averaging about 50 minutes, and energy has usually been the limiting factor. We may be able to increase that to drives of an hour and a half."

Spirit has driven about 9 meters (about 30 feet) since getting around a rock that temporarily blocked its progress on Jan. 31. The team's goal in coming weeks is to navigate the rover over or around a low plateau called "Home Plate" to get to an area targeted for scientific studies on the other side of Home Plate.

JPL's Jennifer Herman, a rover team engineer, found the first evidence for the new cleaning event in engineering data from the Martian day 1,812 of Spirit's mission on the Red Planet (Feb. 6, 2009) and confirmed it from the following two days' data. Before the event, dust buildup on the solar array had reached the point where only 25 percent of sunlight hitting the array was getting past the dust to be used by the photovoltaic cells. Afterwards, that increased to 28 percent.

"It may not sound like a lot, but it is an important increase," Herman said.

The last prior cleaning event that was as beneficial as this one was in June 2007. Winds cleaned off more of the dust that time, but a dust storm in subsequent weeks undid much of the benefit.

Spirit's twin rover, Opportunity, drove 135.9 meters (446 feet) on Feb. 10. Opportunity's cumulative odometry is 14.36 kilometers (8.92 miles) since landing in January 2004, including 2.58 kilometers (1.6 miles) since climbing out of Victoria Crater on Aug. 28, 2008.

Spirit and Opportunity have been operating on Mars for more than five years in exploration missions originally planned to last for three months. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA's Science Mission Directorate, Washington.

###
Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, California
Guy.Webster@jpl.nasa.gov

NEWS RELEASE: 2009-020

USA.gov
PRIVACY    |     FAQ    |     SITEMAP    |     CREDITS