Comparison of embedded computer systems on board the Mars rovers
The embedded computer systems that are on board the various Mars rovers sent to Mars by NASA have to withstand the high radiation levels and large temperature changes in space and for this reason their computational resources are limited compared to current computer systems commonly used on Earth.[1]
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[edit] Operation issues
Direct teleoperation of a rover on Mars is not possible since the round trip communication time between Earth and Mars ranges from 8 to 42 minutes and the Deep Space Network system is only available for use a few times during each Martian day (sol).[1] Because of this a command team for the rover will plan an entire sol worth of operations and then send it to the rover.[1]
[edit] Autonomy software
A rover uses autonomy software to make decisions based on the observations from its sensors.[1] The autonomy software on rovers is becoming more advanced and for example with each pair of stereo images the Sojourner rover could generate 20 3D points while the MER rovers can generate 15,000 to 40,000 3D points.[1]
[edit] Performance comparisons
| Rover (mission, organization, year) | CPU | RAM | Flash solid state storage | Operating system | CPU time available for the autonomy software |
|---|---|---|---|---|---|
| Sojourner Rover (Pathfinder, NASA, 1997)[1][2][3][4] | 100 kHz Intel 80C85 | 512 KB | 176 KB | Custom cyclic executive | Currently unavailable |
| Pathfinder Lander (NASA, 1997)[1] | 20 MHz MFC (IBM RAD6000 Precursor) | 128 MB | 6 MB (EEPROM) | VxWorks[5] (multitasking) | less than 75% |
| Spirit and Opportunity (Mars Exploration Rover (MER), NASA, 2004)[1] | 20 MHz IBM RAD6000 | 128 MB | 256 MB | VxWorks (multitasking) | less than 75% |
| Curiosity (Mars Science Laboratory (MSL), NASA, 2011)[1][6][6][7] | 200 MHz IBM RAD750 | 256 MB | 2 GB | VxWorks (multitasking) | less than 75% |
[edit] See also
[edit] References
- ^ a b c d e f g h i Max Bajracharya, Mark W. Maimone, and Daniel Helmick (2008) (Jet Propulsion Laboratory and California Institute of Technology); Autonomy for Mars rovers: past, present, and future; published in: Computer, a journal of the IEEE Computer Society, December 2008, Volume 41, Number 12, page 45, ISSN 0018-9162.
- ^ "Mars Pathfinder Frequently Asked Questions: Sojourner Rover". NASA/JPL. April 10, 1997. http://mars.eso.org/MPF/rover/faqs_sojourner.html. Retrieved March 27, 2009.
- ^ Donna L. Shirley and Jacob R. Matijevic (May 10, 1997). "Mars Rovers: Past, Present, & Future". NASA/JPL. http://mars.jpl.nasa.gov/MPF/rovercom/data/ROV_PAST.TXT. Retrieved April 18, 2009.
- ^ Larry Lange (February 18, 1998). "U.S. plays catch-up as robots crawl into new applications". EETimes.com. http://www.eetimes.com/news/98/994news/robots.html/. Retrieved April 18, 2009.
- ^ "Wind River Powers Mars Exploration Rovers—Continues Legacy as Technology Provider for NASA's Space Exploration". Wind River. June 6, 2003. http://www.windriver.com/news/press/pr.html?ID=314. Retrieved August 28, 2009.
- ^ a b "Mars Science Laboratory: Mission: Rover: Brains". NASA/JPL. http://marsprogram.jpl.nasa.gov/msl/mission/rover/brains/. Retrieved March 27, 2009.
- ^ "BAE SYSTEMS COMPUTERS TO MANAGE DATA PROCESSING AND COMMAND FOR UPCOMING SATELLITE MISSIONS". BAE Systems. June 17, 2008. http://www.baesystems.com/Newsroom/NewsReleases/autoGen_108517143749.html. Retrieved November 17, 2008.
