I suspect this will in the end be solved in utmost unsexy, boring and reliable way by solar plus huge NiFe battery and/or hundreds of kilometers of high voltage grid, manufactured by robots from local resources or asteroid mining.
Or somewhat sexier, beamed orbital power or mirrors are less technically challenging than on earth.
Either should be less expensive than hauling nuclear reactors from earth and ensuring they get reliable cooling.
> "manufactured by robots from local resources or asteroid mining."
I feel like this just creates the new problems of operating, powering, and maintaining the robots, plus all the difficulties associated with mining asteroids and refining the mined materials somewhere (presumably somewhere that's not Earth's surface, which means we still need to generate power somewhere off Earth for this to work).
Orbital power has the huge advantage that setting it up is essentially independent of the rest of the mission - we can set up most of the work in advance, so that part doesn't count towards a weight limit and we can abort/wait if it doesn't work. Once a secure base using orbital power is set up, then NiFe should be arranged for redundancy.
I think the heat part would best be Feolite, which is mostly sintered iron oxides, but with some other bits added. It has a tremendous volumetric heat capacity, nearing that of water, but you can crank it way past 100 C without worrying about pressure.
Nuclear appears to be the only realistic contender. But the mission architecture of Artemis goes around the problem by having only short stays on the lunar surface.
Even with nuclear, it can be far safer: small reactors need less containment. There is no risk of fallout without an atmosphere, and no ground water to contaminate.
Still, relying too much on it and failing (melting down) will put in danger the whole human space program. For low-power unmanned applications the RTG remains unbeatable.
- "There is no risk of fallout without an atmosphere"
I'd speculate that it would spontaneously propagate along the lunar surface through electrostatic forces. The fallout particles would be highly charged (self-ionizing), very small, and in a perfect vacuum -- a recipe for some seriously weird dust physics.
> There is no risk of fallout without an atmosphere
Fallout is mostly irradiated material spread by an explosion, so as long as you have a surface and some amount of debris from an accident that doesn’t reach escape velocity you can have fallout.
Rtgs are quite common already indeed and will likely be a part of the solution. But it's a stretch to call nuclear the only contender. Cables are a perfectly valid way to move power around from areas that do get solar exposure. And there are plenty of ways to create batteries or store energy. It might even be possible to use resources on the moon to build those (e.g. a heat battery would be doable).
The key limitation is going to be transporting stuff from earth. Solar panels have a key advantage here: they are pretty light and easy to deploy. There's no wind or weather that will dust them over. And per launch, you can move some significant amount of power generation.
What does the risk profile look like for launching nuclear fuel through our atmosphere? It seems intuitively concerning, but I don't know much about nuclear.
Nuclear is probably most practical for long term generalization, for now I think the approach all crewed landers have proposed to use is to place panels as high up as they can to maximize sunlight duration.
At the poles this could enable some permanent power generation by getting the panels high enough to access permanent sunlight.
People survive Antarctic winters so I can't see that there is a particularly big challenge. There is no atmosphere on the moon so heat loss to the sky is purely radiative whereas in Antarctica you have winds blowing that cool the habitats by conduction.
Solar panels should be able to provide the necessary energy which can be stored in piles of rock and insulation should be able to to prevent the loss.
The 'article' says that the lunar night is rife with problems but doesn't mention what they are. There is no weather after all.
The lunar surface temperature is like -150C at night. And yeah, heat loss is radiative.. to a sink at roughly -273C. And night is 2 weeks long. Just use solar heaters and insulation? Well you have to fly that stuff there first, and also fly whatever equipment and people/robots to make the system.
There are various studies to have stuff survive lunar night without a nuclear source, and it takes on the order of 10kg of stuff to keep a 1kg payload alive. And in turn that takes 100kg of spacecraft/fuel to fly it all there. That’s not including the rocket and its fuel to get to Earth orbit first.
The very large temperature difference between day and night means you can bank heat in the daytime, and cold in the night, and generate power from the difference.
You need a pair of very large bags of regolith to store the heat and cold in, and a gas to percolate through them from radiators exposed alternately to sun and black sky.
Or you can just put up very big reflectors in orbit, lighting up your solar panels. Maybe they pump laser tubes pointed at your solar panels.
Nukes would be a big nuisance, needing constant maintenance, unless you just run a naked pile at incandescent temperature and catch the light coming off photovoltaically.
> Nukes would be a big nuisance, needing constant maintenance, unless you just run a naked pile at incandescent temperature and catch the light coming off photovoltaically.
If we had piles of Pu-240 we could use RTGs, though they wouldn't be very efficient considering the amount of mass we'd have to send.
Running a naked reactor doesn't sound so bad considering there's no atmosphere or water sources to poison -- just stay away from the reactor. Running a steam turbine shouldn't be too hard, but it probably can't be serviced -- if it breaks, you replace it.
Nuke the moon! Right now the topography of the poles necessitates quite tall towers to get into perpetual sunlight; but a bunch of judiciously placed nukes could easily take away most of the shadow-bringers (crater rims) and reduce the tower height necessary to get up into perpetual light to a small fraction of what it would be now.
Just remember: nuke first, then colonize. So, sooner rather than later.
Let's assume 10mm copper wire to the other side of the moon. 3000km long copper wire 10mm in diameter will have 600 ohms resistance. The amount of copper needed is 235 m³, copper at 9t/m³ weighting 2115 tons in total or 21 starship flights costing $21 milion.
Local aluminum will be cheaper, and stonkin' high voltage will be needed to combat the ohmic losses. The 'atmosphere' on the moon is rather extremely dry, so corona losses shouldn't be an issue, you could probably run north of a megavolt w/o too much trouble.
Now, you could lay both conductors in parallel and only need to build the power line half-way around the moon, probably save some dough on prospecting for and constructing pylon sites that way. Alternatively, you could run a single conductor all the way around. Doing that, you could establish a lunar scale magnetic field, though it'd probably be pretty wimpy unless you ran serious kA (MA?) of current, which would mean much bigger conductors etc, but it's fun to think about. Heck, with a loop that big, you'd probably get significant induction from the solar magnetic field .. which might be something to harness, or might just be a headache for your line operators.
Payload to low earth orbit might be 100+ tons each. But payload to lunar surface is a small fraction of that. We could assume 10 tons. So 210 starship flights.
One can see pretty quickly that any larger constructions far from earth would really benefit from maximum use of local materials.
There wont be much left on the other end because of volt drop in cables. But can be possible to make it into a HVDC transmission line. Will add bit of weight on the starship.
How awesome would it have been if Artemis actually carried a payload to just dump off on the moon? It's just so absurd that this feat of engineering and rocket science just did a fly by/test.
To make your power go further, we'd want some impressive insulation in our structures. Aerogel comes to mind, but it's low density and fragility means shipping it by rocket from Earth wouldn't work. However it may be possible to make it locally - the moon has lots of aluminum oxide, but we'd have to ship the water & alcohol needed for synthesis. Removing the water and alcohol after the aerogel structure gets created is done with freeze-drying, something that is easy on the moon, and the water + alcohol can probably be recovered for reuse in the next batch.
Downside to aerogel? It makes for a lousy micro-meteoroid and radiation blocker, unlike something like rockwool that masses more.
The moon is a near vacuum, so aerogel is the wrong approach. The main form of heat loss is radiative, and the way to reduce radiative loss is with many layers of shiny things. This works like the superinsulation between layers of a Dewar flask. It could be literally a layered structure or a filling of shiny fluffy stuff inside something else. This will dramatically outperform mineral wool or really anything practical on Earth. All this insulation goes on the outside, vacuum side of whatever pressure vessel people live in.
To the extent the lunar atmosphere is dense enough to cause meaningful conductive loss, one could pump a better vacuum inside the insulation. The pressure difference between this high vacuum and the lunar atmosphere would be low, so the mechanical strength needed for whatever container holds it would be corresponding low. (This seems very unlikely to be a problem at all. The moon’s atmosphere has an extremely low pressure. Offgassing from the insulation seems like a bigger concern.
Just hang your room from a wire (or 3) and wrap the thing in aluminized (or gold) mylar reflector. You've got an almost perfect thermos. Pretty quickly, you'll have to dump waste heat. Now cooling is pretty easy since just need a radiator in shadow. You could run a full on heat pump if you wanted to collect and store power, but this isn't like earth where there's an atmosphere with wind and rain. Or a place where there isn't always a significant solid angle of 3k space to radiate to, most of the sky is always night.
It's just weird to me that they wouldn't go to the interesting and water/gas rich craters perpetually at the terminator. You've always got power there... just start digging.
What about a large reflector dish grabbing sunlight at some distance from the Moon in a geosynchronous orbit, bouncing energy to a receiving station at the new Artemis site?
Luna-synchronous is a long way from the moon. So far away, in fact, that you're it.
L1 would be easier, but that's still 58 megametres from the moon. Possible, of course, but I'd be surprised if that was really better than a big wire on the lunar surface.
Putting the base at the South Pole of the moon is the current plan. But missions will want to go into craters, which will lead them to have to deal with the long nights
[+] [-] rini17|3 years ago|reply
Or somewhat sexier, beamed orbital power or mirrors are less technically challenging than on earth.
Either should be less expensive than hauling nuclear reactors from earth and ensuring they get reliable cooling.
[+] [-] 6177c40f|3 years ago|reply
I feel like this just creates the new problems of operating, powering, and maintaining the robots, plus all the difficulties associated with mining asteroids and refining the mined materials somewhere (presumably somewhere that's not Earth's surface, which means we still need to generate power somewhere off Earth for this to work).
[+] [-] yyyk|3 years ago|reply
[+] [-] mjevans|3 years ago|reply
[+] [-] at_a_remove|3 years ago|reply
[+] [-] TomK32|3 years ago|reply
[+] [-] wankle|3 years ago|reply
[+] [-] iwwr|3 years ago|reply
Even with nuclear, it can be far safer: small reactors need less containment. There is no risk of fallout without an atmosphere, and no ground water to contaminate.
Still, relying too much on it and failing (melting down) will put in danger the whole human space program. For low-power unmanned applications the RTG remains unbeatable.
[+] [-] perihelions|3 years ago|reply
I'd speculate that it would spontaneously propagate along the lunar surface through electrostatic forces. The fallout particles would be highly charged (self-ionizing), very small, and in a perfect vacuum -- a recipe for some seriously weird dust physics.
[+] [-] dragonwriter|3 years ago|reply
Fallout is mostly irradiated material spread by an explosion, so as long as you have a surface and some amount of debris from an accident that doesn’t reach escape velocity you can have fallout.
[+] [-] cratermoon|3 years ago|reply
Studies have shown that in lunar vacuum, fine dust in the regolith can travel halfway around the globe and even end up in lunar orbit and beyond with just a little kick. https://www.theverge.com/2019/7/17/18663203/apollo-11-annive...
[+] [-] jillesvangurp|3 years ago|reply
The key limitation is going to be transporting stuff from earth. Solar panels have a key advantage here: they are pretty light and easy to deploy. There's no wind or weather that will dust them over. And per launch, you can move some significant amount of power generation.
[+] [-] Stupulous|3 years ago|reply
[+] [-] Vox_Leone|3 years ago|reply
The absence of atmosphere would make it viable to beam electrical energy down from orbit. Seems cheaper.
[+] [-] dotnet00|3 years ago|reply
At the poles this could enable some permanent power generation by getting the panels high enough to access permanent sunlight.
[+] [-] kwhitefoot|3 years ago|reply
Solar panels should be able to provide the necessary energy which can be stored in piles of rock and insulation should be able to to prevent the loss.
The 'article' says that the lunar night is rife with problems but doesn't mention what they are. There is no weather after all.
[+] [-] GlenTheMachine|3 years ago|reply
[+] [-] johnwalkr|3 years ago|reply
There are various studies to have stuff survive lunar night without a nuclear source, and it takes on the order of 10kg of stuff to keep a 1kg payload alive. And in turn that takes 100kg of spacecraft/fuel to fly it all there. That’s not including the rocket and its fuel to get to Earth orbit first.
[+] [-] moloch-hai|3 years ago|reply
You need a pair of very large bags of regolith to store the heat and cold in, and a gas to percolate through them from radiators exposed alternately to sun and black sky.
Or you can just put up very big reflectors in orbit, lighting up your solar panels. Maybe they pump laser tubes pointed at your solar panels.
Nukes would be a big nuisance, needing constant maintenance, unless you just run a naked pile at incandescent temperature and catch the light coming off photovoltaically.
[+] [-] cryptonector|3 years ago|reply
If we had piles of Pu-240 we could use RTGs, though they wouldn't be very efficient considering the amount of mass we'd have to send.
Running a naked reactor doesn't sound so bad considering there's no atmosphere or water sources to poison -- just stay away from the reactor. Running a steam turbine shouldn't be too hard, but it probably can't be serviced -- if it breaks, you replace it.
[+] [-] sfifs|3 years ago|reply
[+] [-] Nomentatus|3 years ago|reply
Just remember: nuke first, then colonize. So, sooner rather than later.
[+] [-] a9h74j|3 years ago|reply
[+] [-] dvh|3 years ago|reply
[+] [-] greenbit|3 years ago|reply
Now, you could lay both conductors in parallel and only need to build the power line half-way around the moon, probably save some dough on prospecting for and constructing pylon sites that way. Alternatively, you could run a single conductor all the way around. Doing that, you could establish a lunar scale magnetic field, though it'd probably be pretty wimpy unless you ran serious kA (MA?) of current, which would mean much bigger conductors etc, but it's fun to think about. Heck, with a loop that big, you'd probably get significant induction from the solar magnetic field .. which might be something to harness, or might just be a headache for your line operators.
[+] [-] Aspos|3 years ago|reply
Would heat pumps work on the moon?
[+] [-] orbital-decay|3 years ago|reply
Where can I book a Starship flight for $1M?
[+] [-] Gravityloss|3 years ago|reply
One can see pretty quickly that any larger constructions far from earth would really benefit from maximum use of local materials.
[+] [-] am_lu|3 years ago|reply
[+] [-] whycome|3 years ago|reply
[+] [-] burnished|3 years ago|reply
[+] [-] ngoilapites|3 years ago|reply
[+] [-] nine_k|3 years ago|reply
[+] [-] chiph|3 years ago|reply
Downside to aerogel? It makes for a lousy micro-meteoroid and radiation blocker, unlike something like rockwool that masses more.
[+] [-] amluto|3 years ago|reply
To the extent the lunar atmosphere is dense enough to cause meaningful conductive loss, one could pump a better vacuum inside the insulation. The pressure difference between this high vacuum and the lunar atmosphere would be low, so the mechanical strength needed for whatever container holds it would be corresponding low. (This seems very unlikely to be a problem at all. The moon’s atmosphere has an extremely low pressure. Offgassing from the insulation seems like a bigger concern.
[+] [-] kurthr|3 years ago|reply
It's just weird to me that they wouldn't go to the interesting and water/gas rich craters perpetually at the terminator. You've always got power there... just start digging.
[+] [-] pfdietz|3 years ago|reply
[+] [-] wankle|3 years ago|reply
[+] [-] ben_w|3 years ago|reply
L1 would be easier, but that's still 58 megametres from the moon. Possible, of course, but I'd be surprised if that was really better than a big wire on the lunar surface.
[+] [-] mishkovski|3 years ago|reply
[+] [-] WalterBright|3 years ago|reply
[+] [-] timerol|3 years ago|reply
[+] [-] djha-skin|3 years ago|reply
[+] [-] pfdietz|3 years ago|reply
(cue Everybody Wants To Rule the World)
https://www.youtube.com/watch?v=SRMDcC0QvFQ
[+] [-] nuker|3 years ago|reply