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What is the fastest rover currently moving on the surface of another celestial body? At what speed with our technology currently does physics restrict our speed limits on the surfaces of solar system bodies?

Polygnome
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Cornelis
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    If you expect high speed rovers, you should provide high speed motor ways on other planets. – Uwe Jul 14 '18 at 18:26
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    @Uwe I do not possess the organizing talent to deliver such an infrastructure in time. – Cornelis Jul 14 '18 at 18:31
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    Does the Apollo Lunar Rover count? Because that was way faster than current robotic rovers. – Hobbes Jul 14 '18 at 18:53
  • @Hobbes Don't we have to distinguish between unmanned and manned ? I've asked for currently too, although the Lunar rover still exists ! – Cornelis Jul 14 '18 at 19:12
  • @Hobbes I think you've nailed it. – Organic Marble Jul 14 '18 at 19:12
  • @Hobbes Is the Apollo Lunar Rover still intact ? Could you drive with it straightaway ? – Cornelis Jul 14 '18 at 19:24
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    The state today of the Lunar Rovers is discussed here: https://space.stackexchange.com/questions/2095/can-i-borrow-a-lunar-rover – Hobbes Jul 14 '18 at 19:44
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    You surely do not mean in space, but on the surface of other celestial bodies? – Polygnome Jul 15 '18 at 07:55
  • @Polygnome By definition, a rover is a vehicle designed to move across the surface, but indeed the choice of "celestial bodies" would be less confusing. – Cornelis Jul 15 '18 at 08:34
  • @Conelisinspace Yes, but you have to reach the surface somehow, first. During transit, those rovers move significantly faster (e.g. over 11km/s for the Lunar Rovers), albeit not under their own propulsion. for comparison, for this Q&A, the speed that the roadster achieved while in the fairing/attached to the rocket was the relevant figure. That is why I think it would be beneficial to make the question more clear (mention surface velocity & own propulsion). – Polygnome Jul 15 '18 at 10:27
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    The reason that rovers are so slow is not really a physics issue but rather a cost and safety issue. A Mars rover is incredibly expensive and speeding it up so that it drives a bit faster at the risk of getting it stuck, crashing it, or otherwise damaging it is a gamble nobody wants to make when billions of dollars and possible years of future science are on the line – Dragongeek Jul 17 '18 at 11:18
  • If you accept answers you will get more response then not even if they are not the answer your looking for. – Muze Oct 30 '18 at 02:30

3 Answers3

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The manned Apollo Lunar Roving Vehicle from Apollo 17 holds the record of 17km/h achieved by Eugene Cernan. Apollo Lunar Roving Vehicle was also present on Apollo 15 and 16.

For traditionally understood rovers - unmanned mobile landers, the fastest historically would be Lunokhod 1 and 2, capable of 2km/h.

At current time only two rovers are still active and operational: Curiosity: 0.14 km/h and Opportunity: 0.18 km/h.

Let's add for the record: Yutu: 0.2 km/h, Spirit, same as Opportunity: 0.18 km/h, Sojourner: 0.024 km/h. I believe this is the complete list of rovers that actually drove over the surface of remote celestial bodies to date.

Tim
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SF.
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    Hundred and forty meters per hour!? That is unbelievably slow. Wow! – sampathsris Jul 15 '18 at 05:06
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    Still faster than Southern Rail – James K Jul 15 '18 at 13:39
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    @Krumia: Note how every couple meters there's an interesting rock formation that is worth analyzing. Therefore it's practically unheard of for it to drive continuously for more than a couple minutes. (and how do you like Sojourner's 24 meters per hour?) – SF. Jul 15 '18 at 14:18
  • Did Yutu actually drive at 0.2 km/h ? Do you have a link ? – Cornelis Jul 15 '18 at 16:19
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    The rovers could drive much faster if they had a flat, hard, level surface without obstacles. They could be as fast as autonomous cars on Earth if there is the necessary power and a surface comparable to a road. – Uwe Jul 15 '18 at 20:21
  • @Uwe: A typical off-road 4x4 can still drive much faster than these rovers, and in harder terrain. It's just the rovers really don't need to be fast - and with the scarcity of power needed for all the varied task, fast, power-hungry motors would be detrimental to the mission. – SF. Jul 15 '18 at 21:01
  • @Conelisinspace: I don't know - this speed is listed as its capability, and rovers frequently have just one speed. – SF. Jul 15 '18 at 21:03
  • @SF You may compare a typical off-road 4x4 if it drives autonomous under full computer controll. – Uwe Jul 16 '18 at 16:04
  • @use: in their current form, the rovers can't drive faster than the speeds listed here. It's the design speed of the drive train. – Hobbes Jul 16 '18 at 17:52
  • @Uwe: Winner of DARPA grand challenge 2005 averaged 30.7km/h through Mojave desert. – SF. Jul 16 '18 at 21:14
  • @SF: To be comparable with a Mars rover, this pass should not been used by DARPA grand challenge 2005. Of course also none of the roads within Mojave desert. – Uwe Jul 18 '18 at 09:42
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The highest speed was recorded by an Apollo Lunar Roving Vehicle:

The rovers were designed with a top speed of about 8 mph (13 km/h), although Eugene Cernan recorded a maximum speed of 11.2 mph (18.0 km/h), giving him the (unofficial) lunar land-speed record.

Unmanned rovers have much lower top speeds. Their speed is limited by the amount of terrain they can see and by the amount of autonomy they have. Curiosity has 3 driving modes:

  • fully programmed (using one sol's images to plan driving for the next sol in detail). This is the fastest mode.
  • partly programmed
  • autonomous, with image analysis (finding the safest route, checking for slope angles and obstacles) happening onboard. This is limited by onboard computer power, and is the slowest driving mode.

"Curiosity takes several sets of stereo pairs of images, and the rover's computer processes that information to map any geometric hazard or rough terrain," said Mark Maimone, rover mobility engineer and rover driver at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The rover considers all the paths it could take to get to the designated endpoint for the drive and chooses the best one."

Curiosity's top speed is 137 meters/h (0.085 mph).

2012rcampion
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Hobbes
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To answer the second half of the question: rover speeds are primarily limited by practicality, rather than the physics or technology needed to drive on an extraterrestrial surface. As Elon Musk demonstrated, it's physically possible to send a very fast land vehicle out of Earth's gravity well. If you wanted to waste a lot of money, you could put a 200 kmh rover on another world. However, no scientific agency does this, because space launches are expensive and mass-limited. Every gram you use for motors, wheels, or suspension is a gram that you can't use for experiments or communications. No luxury seats with Corinthian leather either.

The Mars rovers have extraordinarily light weight wheels, and just enough motor to traverse the difficult terrain (with appropriate safety margins). High speed is neither necessary nor particularly desirable.

Foo Bar
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    That very fast land vehicle of Elon Musk will be totally useless when placed on Mars or Moon. – Uwe Jul 16 '18 at 16:12
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    Good link to the wheels though ! – Cornelis Jul 17 '18 at 08:12
  • @Uwe, I'd bet there are a few flat spots on Mars where a consumer electric car could drive, but even if not, existing rover speeds are orders of magnitude below what's possible. – Foo Bar Jul 18 '18 at 16:58