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
image link to mission page
image link to summary page
image link to rovers update
Where are they now?
month in review
image link to mission team
image link to launch vehicle
link to spacecraft page
Cruise Configuration
Entry, Descent, and Landing Configuration
Aeroshell
Parachute
Airbags
Lander
Surface Operations Configuration
Rover
Instruments
link to mission timeline page
communications to earth
Spacecraft: Aeroshell

What is the transverse impulse rocket system (TIRS)?

A rocket system called the transverse impulse rocket system (or TIRS, pronounced "tears") reduces the horizontal speed of the lander at touchdown. It consists of three small rockets mounted on the backshell. Using the backshell interial measurement unit (or IMU), when the rover's software detects that the backshell may be tilted too far off vertical, the software elects to fire one or two of these small TIRS rockets reduce the tilt effect. While not providing precision control, these little rockets can compensate for the swinging introduced by some of the worst winds predictable. Firing for a fraction of a second, these rockets provide just enough of a kick to the backshell to get it aligned with the vertical before the lander and rover are released some 15 m (49 ft) above the ground.

Find out more about the TIRS innovation in the Technology Section.
USA.gov
PRIVACY    |     FAQ    |     SITEMAP    |     CREDITS