WE don't know, but an outpost of some kind on the Moon where we could put astronauts for 6 months or more at a time, could tell us some of that. A VERY useful bit of info for Mars missions, or other long duration mission if there's any potential for considering generating artificial gravity.
After such an expensive, but sustained campaign on the Moon, surely this would provide experience to reduce the cost of the subsequent Mars mission?
cheers, Martin
I agree with the above.
And such a Moon base operated for ten years may very well cost the same as the first Mars mission.
Bingo. We could have a vibrant, permanently manned Lunar station for the cost of a single, short-stay Mars mission.
It's a significantly different environment.
Not really.
A short-stay Mars mission would spend the vast majority of the time in transit or in orbit.
So why bother?
The lander would have to be very different (Mars one would need to take aerodynamics into consideration, lunar one wouldn't), so unless you designed the lunar lander to Martian conditions from the get-go (a lot more expensive), you'd have to do the designing twice, and the lunar one would still be quite suboptimal.
Not necessarily true: e.g., take the ULA DTAL Lunar lander: according to Zegler and Kutter, it's cigar shape is preadapted to endoatmospheric flights, and a Mars lander would be a straightforward upgrade of the ACES-41 version. Upgrading the lander would simply be a matter of stretching the tank to the ACES-71 version, and maybe swapping out the RL-10's with RL-60's. You'll want to make the skin out of a heat resistant material like Inconel nickel alloy. That's pretty much about it. A true 2 for 1.
The Moon would have to deal with a uniquely brutal sort of dust contamination for long-term missions (Apollo showed that short-term is not a huge issue, though annoying) whereas Mars's dust is pretty similar to certain terrestrial dust because both are formed primarily through wind processes.
Brutal?

That's funny! At least Moon dust isn't
poisoned with loads of perchlorates (forgot about Phoenix already, eh?). Yeah, you don't want to be breathing Moon dust, but believe me, you don't want to breath Mars dust either. There are Earth environments where the dust is as bad (mining, asbestos removal, air drilling). But they'll be wearing "spacesuits" with self-contained breathing, so it won't be a health issue. Setup a shower and vacuum system in the airlock. You'll have to do that at both Moon and Mars anyway. Another 2 for 1. Mars has no advantage in terms of nastiness of the dirt.
Indeed, I don't see how you'll be able grow crops in a greenhouse on Mars. I guess it'd have to be all hydroponic. On the Moon, however, once fertilized with compost, Lunar soil would make a great growing medium; it would be like a fresh volcanic soil on Earth. Plants will love it.
ISRU would be vastly different between the two celestial bodies, with Mars ISRU being a lot easier since you can just suck in the Martian atmosphere and avoid having to do any regolith processing.
Yeah, but you got to put in on the critical path. And so you better hope it works for two years before the humans land. And then you only get substandard Isp propellant for your efforts. Zubrin wanted to import LH2 from Earth....
On the other hand, if you did develop a Lunar ISRU capability, then transferring that technology to Mars would be a piece of cake. This is especially important if you want a permanently manned station on Mars. You'll want to be able mine your own water out of the Martian regolith. Developing this capability as part of the Lunar program means that the Mars program won't have to spend money developing this capability. Another 2 for 1.
And the Moon still doesn't give you experience with the sort of autonomy from ground control needed for a Mars mission (though I suppose that could be done artificially).
Yes.
I don't see any areas which show that a decade of living on the Moon would give us a huge advantage in cost for a subsequent initial Mars mission beyond what can be achieved on a place like ISS for a lot less and a lot sooner.
Let's see: (1) Lander; (2) dust mitigation; (3) regolith processing; (4) gravity in 1/6 g; (5) abundant Lunar propellant; (6) propellant depots; (7) reusable MTV's built out of leftover Lunar 3rd stages
I suppose if you have a flexible enough Mars lander (i.e. not well optimized to Mars), you could test it on the Moon first, but that doesn't seem to justify a full lunar base with all the logistics and cost that'd entail.
The main value of a Lunar station is that it keeps US skin in the Moon game. This has nothing to do with Mars.
Moreover, an optimal Mars lander would be fully propulsive. This would give it the capability to make a pinpoint landing anywhere on Mars surface without having to worry about the atmospheric density. Yeah sure it requires more propellant than landing with parachutes that can fail and hefty heat shields, but it's a lot easier to design, and the extra propellant required can be imported from the Moon.
Another issue is that a lunar base would have higher radiation doses than a Martian one (at lower altitudes), so astronauts on an EVA would always have to fear a big solar particle event, while astronauts on Mars would have the advantage of a significant atmosphere that filters out solar particle events to non-life-threatening levels.
Not an issue. Moon will have radiation protected habitats. Early warning of solar flares will be provided by a satellites at the Earth Sun L-1 point.
Lunar structures would also have to contend with micrometeorites, something that's not an issue on Mars because of Mars's atmosphere.
Well, after 50 years of spaceflight, there has yet to be a loss of a vehicle or human life to a micrometeorite. Evidently, there's no crisis there.
Also, the Moon has much larger temperature swings because of its utter lack of atmosphere.
Wrong. At permanently illuminated plateaus in the polar regions, the ambient temperature is a balmy -50 degrees plus or minus 10 degrees. Arguably better than South Pole Station in the winter.