# Why do we not have ten small rovers on the Moon already? [closed]

We already did the develop and testing of Opportunity and Curiosity for 15 years. Why not crank out ten more, and put them on a Falcon heavy for the Moon's south pole?

• "Why didn't we do something" invites opinion based answers. Can you edit your question to make it less subjective? Jul 27 '19 at 13:29
• Jul 27 '19 at 13:59
• Opportunity and Curiosity were designed to work on Mars, you need a different design for the Moon due to the long and cold lunar nights and the lower gravity.
– Uwe
Jul 27 '19 at 15:06
• Please include your assumptions in the question. Why do you think falcon heavy is a good fit to launch payload to the moon? Why do you think it is comparable to operate landers and rovers in moon compared to Mars? Why do you think Mars rover can bring science by operating on Moon's south pole? Jul 27 '19 at 15:19
• +1 because I think the four down votes were needlessly punitive for a new user's first question. Those down voters are not likely to reverse their votes if the OP rewrites the question, so I don't see them as welcoming. The helpful comments and close votes on the other hand are constructive and help the new user understand how to improve the question and ask better next time.
– uhoh
Jul 27 '19 at 22:45

There are several over lapped reasons, and they add up to only being able to afford a rover every couple of years, so they get sent to mars where more science can be done.

The launcher size/cost is similar due to the fact that a mars lander can aerobrake, while a lunar one needs to make a powered descent.

Power is a major problem on the moon, since the 14 day night makes solar power problematic, and even if the rover sleeps it still needs to keep the batteries warm enough to function at sunrise. Radioistope heaters or RTGs both help for this but there has been a global shortage of the required material. Pretty much all of it available has gone into the missions that did fly. There are places getting steady sun, but a rover would have to leave them to actually rove, and the quest for water would mandate time in regions getting no sun at all.

A substantial part of the mission cost is the ground team that manage the mission - salaries, antenna time, infrastructure etc. These are much the same for moon and mars, though the shorter time delay and lower attenuation do help.

Science wise even Curiosity is only able to look at surface rocks with a finite number of instruments. Apollo brought back rocks that have been repeatedly revisited as technology improves, and the human deployed instruments investigated a number of things that still have not been done on mars

So if the decision was made to fly a lunar rover mission at least one major mission would have had to be cancelled to fund it, and that for one rover rather than a herd. How that stacks up in calculus of politics vs science vs mission planing is harder to quantify and goes into opinion based. Certainly if they really do get people back to the moon in the next couple of years looking for water it would be valuable to already have a rover pinning down the best landing site for that goal.

• Gremlin: you make some good points. I was over simplifying a moon mission but Nasa head Bridenstine recently said Nasa has ten lunar payload ready to go. Tiny little Israel just almost landed a craft on the moon and Nasa can't? Musk just recently said "it would be easier for him to just go land on moon than trying to convince Nasa that he could do it." Jul 27 '19 at 14:25
• @dog.ponders.calculus I think we probably actually agree, in a world where missions did not need to be sexy to get approved and planning could be done long term without political tampering (see lunar gateway and the RTG shortage) there are many useful things to be done on the moon. They however do not pay off in the current voting cycle so get punted down the priority list. Jul 27 '19 at 23:21

If the Curiosity Rover would work at all on a totally different enviroment such as the moon there is the fact that we do not have a big enough supply of plutonium of the right grade to power it. Combine this with a very long and cold lunar night and it looks like another rover design is needed.

Add to this the cost of building and launching the rovers which would be huge, mony which could be spent better elswhere.

• Correction: I meant Opportunity and Spirit which are solar power. Jul 27 '19 at 13:32
• lijat: long and cold lunar nights? the reason the lunar south pole is being considered for a base is it's almost constant solar radiation year round. Jul 27 '19 at 13:36
• lijat: the cost...would be huge- they have the blueprints; what is the cost of a little aircraft aluminum and titanium? Since Mars is about one quarter the gravity of the moon, it would be over built. The cost a Falcon 9 is 90 million dollars; that is cigarette money for Nasa or about two days of expenses for Boeing (which has been pondering sending something to space for 15 years.) Jul 27 '19 at 13:45
• correction: the Moon is about one quarter the gravity of Mars. Jul 27 '19 at 13:47
• @dog.ponders.calculus One quarter? Lunar surface gravity is about 0.16g (about 1/6 of Earth), Mars surface gravity is about .38g (roughly 1/3 of Earth). It would be more correct to say that Lunar surface gravity is about 1/2 that of Mars, not 1/4.. Jul 27 '19 at 15:03