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Comment by rini17 | Hacker News Reader

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.

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> "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).

I am still awaiting the future promised me where 3d printers replicate themselves. This is orders of magnitude easier than robots making themselves in outer space, yet we are still waiting and I assume we always will be.

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.

Bootstrapping issue. Probably going to need the initial bots to have RTG based power mostly as a self-heater.

What’s wrong with operating half the day? I guess it’s space, so it’s worth a lot of effort, but I’d think if they can avoid RTGs and just use solar they would.

The night is 14 days long and is deeply (cryogenically) cold, which is really bad for lots of hardware. Military component ratings are something like -55°C[1]. Lunar night is more like -130°C.

Ideally you keep as much equipment as close to an even temperature as you can, or it might never turn on again when daylight comes.

[1]: the exact definition varies, but it's in that general area. Industrial is -40°C and commercial is 0.

Right, everything except solar panels should be underground, not only because of temperatures but to keep the regolith away too.

humans use to build with mud, sometimes with walls meters thick. Underground or natural caves would be even better. It doesn't get any less sexy. Not sure how it works with such extremes but on earth it takes months of heating or cooling to get through a few meters of soil.

There's another bootstrapping issue there: how do you get the underground base installed and functional in less than 14 days?

Why must the build be done all at once in one go? Humans will land at the dawn, leave before dusk, working in 14 day shifts set up the base. This will repeat for several months till the base gets self-sufficient enough.

Some stations in Antarctica were built that way only during summers, in winters they were left empty till finished and operational.

I would think that the first generation base would be situated at the poles with perpetual (or as close as possible) sunlight.

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.

One of my all time favorite everyday engineering things I've learned is the absolute bonkers amount of energy needed to boil water (vs nearly any other fluid).

It's so commonplace yet absurd/impressive when you really think about it.

How about two bases? Simply move people and critical experiments to the other base before nightfall.

Travelling a few thousand km is probably harder than just running a wire around the moon ;)

Especially when you have to do it every 2 weeks.

But is it the same amount of fun?

You probably want to travel anyways for exploration and mapping.

Do you? If we assume robots building stuff. Mapping is a task way easier to automate.

Lunar cowboys arent gonna be robbing no wire, nosirree, lunar rail is a necessity.

We can’t outrun it forever…

One base, on stilts, constantly walking with the sun.

Going to need roads for that. Might as well construct rails. A circum-lunar railway! Probably want to build that at 80 degrees latitude or more, the trade off being solar angle vs material costs.

God, frickin lunar railways. Truly the future of everything.

And they don't have to be big. More on the scale of those little trains at fairgrounds.

If you build rails, you'll get a free good-enough conductor for getting power from the other side, even before you think about putting anything onto those rails.

That's not a new idea, it's in a book already: https://www.goodreads.com/book/show/23848027-new-moon

How would a lunar railway handle thermal expansion? We’re back to the same problem that the nighttime lunar surface is mighty cold, and I’d expect big gaps to form

I have no idea how plausibly, but the book 2312 has a city on one of the hot inner planets that gets squeezed along a rail using thermal expansion. Even if that doesnt work, it seems like the sort of thing you could engineer around, just a more extreme version of the engineering we already do to handle thermal expansion.

Won't this throw up too much dust?

Then leave and wait for it to start sending us poetry about its constant mortal fear of the night :)

[1] https://youtube.com/watch?v=4PUIxEWmsvI

I believe I read a book on Mercury where they did the reverse - a giant moving city to stay out of the direct sunlight.

I feel like that might have been Charles Stross "Saturn's Children". Been a long time since I read it though so I may be wrong.

That is the book I was remembering!

That was Kim Stanley Robinson's 2312:

https://en.m.wikipedia.org/wiki/2312_(novel)

https://en.wikipedia.org/wiki/Peak_of_eternal_light

NiFe batteries last for decades, I agree that would be the best choice for the battery type.

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