Timeline for Why are Mars rovers so slow?
Current License: CC BY-SA 3.0
12 events
| when toggle format | what | by | license | comment | |
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| Oct 13, 2016 at 13:04 | comment | added | Ian | Wait, THE @MarkAdler? | |
| Apr 9, 2015 at 7:18 | comment | added | Aerophilic | One additional note, Generally rovers on Mars use what are called "Harmonic Drive" gearing. The upside of this type of gearing is that you are able to use very efficient brush-less motors, operating at high speeds (where they are most efficient), yet at the same time get a ton of torque. One downside of this gear is that you lose the ability to "back drive" the motor. | |
| Jun 21, 2013 at 20:03 | history | edited | Ian | CC BY-SA 3.0 |
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| Jun 21, 2013 at 17:48 | history | edited | Ian | CC BY-SA 3.0 |
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| Mar 20, 2013 at 20:27 | comment | added | hobs | And the ultimate cause for this JPL preference for hardware vs. software to overcome obstacles came about because: 1. autonomous path planning software wan't reliable enough at the time the vehicles were built. 2. the best rad-hard power-efficient processors couldn't handle the load of the path-planning algorithms of the time 3. the delay between ground and rover prevents teleoperation by a human to avoid obstacles | |
| Dec 24, 2012 at 19:58 | comment | added | Ian | From what I understand, it's a combination of the uneven thermal expansion of components and the freezing/gel-ing of the lubricants. c3p0.ou.edu/irl/theses/roman-ms.pdf | |
| Dec 22, 2012 at 19:25 | comment | added | Ansis Māliņš | What problems are caused by very low temperatures? | |
| Dec 15, 2012 at 15:20 | comment | added | Mark Adler | As it happens, on Curiosity, the main energy limitation on mobility per sol is not the energy to run the motors, but rather the energy to heat the motors and gear boxes up to their operating temperature in the morning. What we really need are motors and gear boxes that can operate at ambient Mars temperatures. The MSL project tried to develop those, but ran into problems and fell back to the existing technology. | |
| Dec 15, 2012 at 5:12 | comment | added | user626 | @MarkAdler All true, but any rover designed to save power to use in a quick burst would have to carry around a very hefty battery for that purpose, so a high-quality suspension is not the only impediment. | |
| Dec 14, 2012 at 18:55 | history | edited | Ian | CC BY-SA 3.0 |
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| Dec 14, 2012 at 18:09 | comment | added | Mark Adler | Correct! That is the main reason, and it derives from the need for safety and predicability. It is very expensive to get a rover to Mars, and it is priceless once there. Energy is a factor for the distance per sol, but not so much for distance per hour. You could imagine a faster rover that has more time in the day for other (not so energy-intensive) activities. Communication limitations are not as much of a factor, since autonomy could allow quite a bit of roving in a sol if suspension and energy were not a factor. The Curiosity processor is much faster than on Spirit and Opportunity. | |
| Dec 14, 2012 at 16:15 | history | answered | Ian | CC BY-SA 3.0 |