Comparison of the embedded computer systems of the Mars rovers

from Wikipedia, the free encyclopedia

The embedded computer systems on board the Mars rovers , which were launched by NASA , have to withstand high levels of radiation and strong temperature fluctuations. For this reason, their computer resources are limited compared to ordinary computer systems on earth.

overview

Direct teleoperation of a Mars rover is impractical because the radio signals travel there and back between Earth and Mars takes 8 to 42 minutes and the Deep Space Network is only available a few times during a Mars day (Sol) . Therefore, a rover command team plans all operational commands as a batch and sends them to the rover at once. The rover thus receives all commands to be executed in reserve.

In addition, a rover uses autonomous software to make decisions based on observing the sensors. For each pair of stereoscopic images, Sojourner Rover (Pathfinder) was able to generate 20 3D points, while the MER was able to generate 15,000 to 40,000 3D points. A long-term trend in Mars rover computing is therefore greater instrument autonomy. Autonomy means that the instrument has its own CPU and operating system ( RTOS or executive). In the end, the instrument can operate on its own with the constant intervention of the CPU that controls the rover. The Mars Science Laboratory has cameras with greater autonomy than some of the other instruments.

Comparative data

Comparison of the embedded computer systems of the Mars rovers
Rover (mission, organization, year) CPU R.A.M. Fixed storage ( Flash , SSD , HDD ) operating system Processor time available for autonomous software
Sojourner Rover (Pathfinder, NASA, 1997) 2 MHz Intel 80C85 512 KB 176 KB Custom Cyclic Executive currently not available
Pathfinder Lander (NASA, 1997)
(base station for the Sojourner rover) 		20 MHz MFC ( IBM RAD6000 Precursor) 128 MB 6 MB (EEPROM) VxWorks ( multitasking ) less than 75%
Spirit and Opportunity ( Mars Exploration Rover (MER), NASA, 2004) 20 MHz IBM RAD6000 128 MB 256 MB VxWorks (multitasking) less than 75%
Curiosity ( Mars Science Laboratory (MSL), NASA, 2011) 200 MHz IBM RAD750 256 MB 2 GB VxWorks (multitasking) less than 75%
Perseverance ( Mars 2020 Rover (MARS2020), NASA, 2020) 200 MHz IBM RAD750 256 MB 2 GB VxWorks (multitasking) less than 75%

See also

Individual evidence

  1. ↑ a b c d e f 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 .
  2. ^ Mars Pathfinder Frequently Asked Questions: Sojourner Rover . NASA / JPL. April 10, 1997. Retrieved March 27, 2009.
  3. ^ Donna L. Shirley and Jacob R. Matijevic: Mars Rovers: Past, Present, & Future . NASA / JPL. May 10, 1997. Retrieved April 18, 2009.
  4. ↑ Larry Lange: US plays catch-up as robots crawl into new applications . EETimes.com. February 18, 1998. Archived from the original on August 27, 2008. Retrieved on April 18, 2009.
  5. ↑ Mars Pathfinder Frequently Asked Questions - What type (s) of CPU does the rover have? How fast is it? How much memory does it have? What other storage devices? . NASA
  6. ^ Wind River Powers Mars Exploration Rovers — Continues Legacy as Technology Provider for NASA's Space Exploration . Wind river . June 6, 2003. Retrieved August 28, 2009.
  7. ↑ a b c d Mars Science Laboratory: Mission: Rover: Brains . NASA / JPL. Retrieved March 27, 2009.
  8. ↑ a b BAE Systems computers to manage data processing and command for upcoming satellite missions . BAE Systems. June 17, 2008. Archived from the original on September 6, 2008. Retrieved on November 17, 2008.