# What limits the Mars Rovers' lifespan? **URL:** \ **Category:** Factual Questions\ **Created:** [March 2, 2004, 9:51pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172 "2004-03-02T21:51:49Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![127.0.0.1](https://avatars.discourse-cdn.com/v4/letter/1/258eb7/32.png) [@127.0.0.1](https://boards.straightdope.com/u/127.0.0.1)\ **Post date:** [March 2, 2004, 9:51pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/1 "2004-03-02T21:51:49Z")
I believe they are powered totally by their solar arrays, so power shouldn’t be a problem, as they switch themselves off at night. Martian weather might be a problem, but NASA could probably see that coming and park the rover back in its landing pad and fold up the petals (anyone know if this is an option?) . any tossing around it got from a martian gale pales in comparison with the beating it took before coming to rest on the surface (granted, the airbags can’t be refilled) What’s left, Meteor impacts? Not any more likely than on earth. Less, maybe–not as much gravity to pull 'em in. Driving off a cliff? Seems like a great deal of time was spent to make sure this doesn’t happen, though not out of the question. So, what is left to limit the life of these rovers? ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [March 2, 2004, 10:00pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/2 "2004-03-02T22:00:25Z")
Complete WAG here, but I’d say just the general hostility of the environment. Large temperature swings in the “really friggin’ cold” range, lots of radiation, dust, that sort of thing. I’d expect that kind of thing to be hard on the electronics. ---
**Author:** ![BMalion](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@BMalion](https://boards.straightdope.com/u/BMalion)\ **Post date:** [March 2, 2004, 10:07pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/3 "2004-03-02T22:07:14Z")
Dust. apparently the dust sticks to the solar panels and there’s also a wicked static cling effect as well. eventually this blocks the solar panels and goodnight sweet prince. ---
**Author:** ![127.0.0.1](https://avatars.discourse-cdn.com/v4/letter/1/258eb7/32.png) [@127.0.0.1](https://boards.straightdope.com/u/127.0.0.1)\ **Post date:** [March 2, 2004, 10:24pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/4 "2004-03-02T22:24:41Z")
Wait, you mean to tell me that such an easy problem to prevent (wipers anyone?) will end up crippling a multi-billion-dollar rover mission? I can’t believe they didn’t think of this. ---
**Author:** ![BMalion](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@BMalion](https://boards.straightdope.com/u/BMalion)\ **Post date:** [March 2, 2004, 10:31pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/5 "2004-03-02T22:31:56Z")
Who said wipers were easy? The mechanism to move the wiper arm would itself have to be sealed from dust. Plus, have you ever tried to wipe off dust or lint with static cling happening? It’s not easy. I believe that they calculated how long it would take dust to cover up the panels and how much power it could have until then and decided that they were happy with what they got. Mind you, I’m no scientist. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [March 2, 2004, 10:47pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/6 "2004-03-02T22:47:02Z")
According to someone from NASA (sorry I don’t remember who, but they were answering questions from reporters) the large temperature swings were the main killer. ---
**Author:** ![beowulf573](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@beowulf573](https://boards.straightdope.com/u/beowulf573)\ **Post date:** [March 2, 2004, 11:04pm UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/7 "2004-03-02T23:04:19Z")
There’s several issues involved: The wide temperature swings as others have noted take their toll on the electronics. There’s a battery that’s changed during the day that powers heaters to keep the rover warm at night. But as anyone with a laptop can tell you, after a while it becomes difficult to recharge batteries, even NASA-priced batteries. As the Martian winter approaches the sun will be lower on the horizon providing less light for the solar panels. And, as other haves noted, the panels accumulate dust which blocks sunlight. A surprisingly difficult problem to solve as it’s very fine dust and statically charged. Then there’s the chance of mechanical failure. As time goes on all of these limit the lifetime of the rovers in one way or another. Hopefully future rovers will use Radioisotope Thermoelectric Generators instead of solar panels. Assuming protests don’t prevent NASA from launching a rover with one. Eddie ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [March 3, 2004, 2:50am UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/8 "2004-03-03T02:50:18Z")
> [@beowulf573](#): > > As the Martian winter approaches the sun will be lower on the horizon providing less light for the solar panels. This is actually pretty significant. It’s one of the reasons almost all the probe missions have been in a fairly narrow equatorial belt (not counting that polar lander that went “boom”), because it provides the most reliable location for generating solar power. The stories I’ve read indicate that the sinking sun alone has been responsible for a drop in lander power of around 25% just in the few weeks they’ve been on the surface. Besides that, I think **Smeghead** got it in one with “general hostility of the environment.” This isn’t like remote-control driving a Radio Shack truck in the back yard. They’re cramming a ridiculous amount of hardware into a tiny space with a non-flexible weight restriction, they’re flinging it off the planet at thousands of miles an hour, they’re piloting it across tens of millions of miles of empty space, they’re dropping it on an alien rock that has virtually no atmosphere and a variety of severely debilitating environmental conditions, and they’re controlling it with a several-minute time delay. The fact that it works at _all_ is a freakin’ miracle. If you want specific technical details of the hurdles the engineers have to overcome to make one of these robots work, I recommend _Managing Martians_ by Donna Shirley, who project-managed the Sojourner rover (the one that went with Pathfinder) at JPL. ---
**Author:** ![aaelghat](https://avatars.discourse-cdn.com/v4/letter/a/c5a1d2/32.png) [@aaelghat](https://boards.straightdope.com/u/aaelghat)\ **Post date:** [March 3, 2004, 4:14am UTC](https://boards.straightdope.com/t/what-limits-the-mars-rovers-lifespan/232172/9 "2004-03-03T04:14:20Z")
I asked that same question in January. This [thread](http://boards.straightdope.com/sdmb/showthread.php?t=235478) has a good discussion of the topic.