It would be awesome if we could land some construction robots onto the moon and Mars. Let’s get going with construction of underground settlements and research stations.
Starship can only land a tiny payload if you expect to reuse it, but if you don't you can likely land 100 tons and reuse the the vehicle for habitat, storage tanks and such. The first thing you land is a lunarized D9 Cat [1]
which digs trenches that let you bury the upper stages under 2 meters of regolith which will give good radiation protection and thermal coupling to a reservoir at a constant and comfortable temperature just below the freezing point of water. I guess you want some kind of crane for handling the Starships but you probably want one anyway if you expect to send them back.
You're not going to be dropping an actual D9, you're going to design something inspired by the DO and others that's optimized for the moon. An actual D9 weighs far too much for the moon and has all kinds of surfaces that couldn't handle lunar dust.
"Lunarized D9" was meant to be evocative. Running a diesel engine on pure oxygen (maybe lunar) and hydrocarbons from Earth with exhaust gas recirculation to keep it from burning up might be possible. But it might be more practical to build something functionally equivalent that uses batteries or fuel cells that is more circular in operation. Studies seem to show though that it is tough for ISRU to compete with shipping in resources from the most competitive market in the solar system. The dust could be a problem, it's like really sharp because it doesn't get weathered which probably makes it bad to get in your lungs.
You might sneak 2 D9s on if you can ship 100 ton, they are apparently 48,988 kg.
You can probably fit more than two Lunapillars, because the stuff they're moving masses the same, but weighs 1/6 as much, as does the machine itself. It's also always dry - no claggy clays on the moon. You may also want to source counterweight locally if you can. It'll be much less dense, but may an acceptable tradeoff to shipping tonnes of metal ballast by spaceship until you can refine out some low-grade iron from regolith.
Presumably also you make many things out of materials like composites, titanium, aluminium, magnesium and abrasion-resistant materials like ceramics to cut weight and prolong part life in an aggressively abrasive environment where your Cat rep and McMaster Carr are a bit more than a phonecall away. Which will be incredibly expensive, but even using Starship, a tonne landed on the lunar surface ain't exactly cheap and every kilogram counts.
Ah, the D9 Cat. A perfect tool to colonize the moon.
Where does the oxygen for the turbines come from? My rough math gets me about 130kg of oxygen per hour to run that cat's diesel engine.
Oxygen is plentiful on the moon but it is bound up with metal and stone elements (Fe, Al, Si, ...). There are many ways to separate the two, for instance if you have a stock of hydrogen or carbon you can reduce most metals with H2 or CO gas and then cleave off the O2 and recycle the hydrogen or carbon.
If you read 70's or 80's sci-fi such as Gerard K. O'Neill's The High Frontier or Haldeman's criminally underated Worlds [1] you'll hear the myth that iron is rare on the moon but it just isn't true, recent remote sensing has discovered huge amounts of hematite
https://pmc.ncbi.nlm.nih.gov/articles/PMC7467685/
and Apollo astronauts found concentrated ilmenite ore back in the day. Hematite would be particularly easy to split into iron metal and oxygen by chemical cycling.
Now carbon, hydrogen, nitrogen are volatiles that seem rare on the moon. Its thought that there is ice in craters at the poles and there is remote evidence of this but we haven't gotten a good look. If we're lucky there is CO2 and/or CH4 in the ice and we have a good carbon source.
[1] written to kill The Moon is a Harsh Mistress the way The Forever War killed Starship Troopers
I may be giving musk too much credit, but I don't think it's a coincidence that the Boring company focused on shrinking and optimizing tunneling machines.
So far Starships can't even go to orbit. It's very likely they'll never see anywhere near the Moon.
I'll take that bet. How much money and what time horizon? I can go so far as cutting down "never" to say 15 years?
They're capable to do it on paper, the real question is whether there's enough money and incentive to do so. SpaceX won't do it out of charity, NASA has had its funding cut, and there's no natural resources or whatever on the moon so it would depend entirely on government, scientific, or rich tourist funding. Same with going to Mars.
Nobody seriously thinks that running the raptors for another minute is some barrier they're unlikely to break; can you clarify what you mean by “can't even go to orbit”?
The case is going to be that they haven't done it yet, but that case could collapse as soon as they manage to really do it -- and perfect reentry and reuse, particularly of the reentry system.
Getting refueling to work is another big challenge.
Assuming that is perfect the performance of a reusable Starship -> Moon -> Earth mission is not that good, landing 3 tons or so, not far off from the Apollo lander. To do better it needs to be refueled on the Moon which has all sort of question marks. O2 can be found on the moon and that's a significant part of the "fuel". Maybe there is CO2 or CH4 or something carbonaceous in the ice at the poles, maybe there isn't. An H2 rocket is a better bet in that department. Tall and tippy Starship would do great landing and taking off from the Moon or Mars if there was a set of chopsticks to catch it, landing on an unprepared surface looks challenging.
These aren't really "Starship" problems, they are problems that affect any vehicle trying to go to the moon. Back in the 1980s I read columns in Analog Science Fiction magazines "Science Fact" columns that tried to say we were sold up the river by the Apollo missions and should have had a more ambitious program, but the round trip to the moon is terribly difficult and Von Braun's mission architecture made the impossible possible
A Mars mission would be a break from the SpaceX experience -- so far SpaceX has been about pursuing commercial opportunities in near earth space, not "exploration".
Rapid turnaround with a lot of hardware can get you to orbit or the moon, but there is no such thing as "rapid turnaround" to Mars where you have to wait 2.5 years for the launch window. 10 tries will take 25 years. Right now SpaceX runs everything by remote control from ground control which is a perfect strategy for NEO, probably good enough for cislunar except for the landing, but landing and takeoff from the Mars requires an autonomous system which is not just a technological but a culture change for SpaceX.
How long would it take how many humanoid robots to construct a flatpacked bulldozer, a tunneling machine, and airlocks?
For a relative definition of comfortable...
Like upstate NY in the winter. If you can maintain shirtsleeves conditions inside an old farmhouse at that outdoor temperature, NASA can do it for astronauts. Contrast that to the surface temperatures which swing from 260°F to -280°F.
The corollary is that ice buried on the moon with a vapor barrier to prevent sublimation could be stable.
Lunar subsurface temperatures even at only 2m depth are stable at around -20C. Considering the very low thermal conductivity of the regolith, and the relative ease of constructing a vacuum-flask-like structure in a vacuum, you can have a thermally stable subsurface habitat at 20C, even if the surface temperature is swinging wildly from -170C to 120C every two weeks.
In fact, you may have more problems venting heat in the lunar day than you will keeping warm in the night - presumably you'd dump the excess heat from the habitat into cold regolith in the day, and then from there either store it for a heat-pump heat source for night-time usage (à la Sand Battery https://polarnightenergy.com/sand-battery/), or radiate it into space at night if your heat dump heats up too much.
> If you can maintain shirtsleeves conditions inside an old farmhouse at that outdoor temperature
I don't know, can you? I would need an indoor temperature at least 18C to be comfortable in shirtsleeves, unless I'm doing something physical.
I'm comfortable in shirtsleeves at 24C (current temperature here) and I'm wearing wool and a scarf if I'm sitting at my desk at 18C. That's why they won't send me to the Moon or to Mars.
With a wood stove, yes. Gets so hot sometimes I take my shirt off entirely.
Now we just need moon wood.
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A YouTube called anthrofuturism has some videos if your interested.
The channel is mainly focused on the moon and how it can help humanity in our reaching to the stars.
Yeah, just drop a bunch of brick generation bots and let them run wild. Come back later and harvest bricks. Seems useful for stuff like landing sites.
Our first attempt at maintaining a habitat and achieving justice is an abject failure, so let's try again in a much more hostile environment!
