On a more serious note, is the high energy demands of this process a blocker at all? Or can we just assume that energy (solar) is abundant on the moon?
I'd say solar panel output would be way more predictable than upon Earth as no chaotic weather systems at play, also larger unfiltered spectrum would mean panels could be tailor made to get higher efficiency than you get per m2 anywhere upon Earth with its atmosphere.
you can visualise it better here and whilst this is measuring upper atmosphere levels and not space - you get an idea: http://butane.chem.uiuc.edu/pshapley/GenChem2/A2/1.html
On serious note isn’t there some type of future plan to put nuclear reactors on the moon in this decade?
In general these processes are energy intensive because they involve temperatures high enough to melt rock. On the Earth that is difficult to achieve because you need to keep the furnace hot. On the Moon with its hard vacuum, a large chunk of rock moved onto insulating material doesn’t radiate much heat. So all you’d need, really, is a large parabolic mirror. The Sun is your power source.
Generally speaking, it’s a high risk, low reward mode.
If you can figure out how to avoid creating dust clouds on the moon, which is not a small if, solar concentrators could provide a lot of the heat for the process, reducing the power needs to the electrochemical part.
The latter works pretty well on the moon because the day is pretty long at almost a month. If you get really creative the slow speed means it might be possible to build a giant tracked refinery that slowly circles the moon so it has continuous daylight.
I wonder if arrays of mirrors (aimed at a heat engine or whatever they use to generate electricity from molten salt) would be cheaper to scale up there.
That seems like a great idea. Find a nice big crater in an area that gets a lot of sunlight and polish the walls of the crater into a parabolic mirror. Put your heat engine at the focus and collect tons of energy. The one drawback: how do you provide cooling? Heat engines are only efficient with a large temperature gradient (Carnot's theorem).
First step to an exo-earth settlement is going to be sending the biggest reactor that will fit on a rocket. Two of them, actually.[1]
Whether its digging, breathing, or making rocket-fuel pretty much everything is going to require, by earth standards, gobs of power. Last thing you'd want to do is operate in a power-starved or even power-adequate environment.
[1]Plus, to be fair, enough backup solar or RTG to keep people alive in case of reactor failure.
Engineers will tinker with the process by adjusting the electrical current and reagents to boost the amount of oxygen while trying to reduce the temperature needed to produce it. This will help bring down the energy required, which is already at a premium on the Moon.
I'll take more dumb jokes over yet another diatribe on how Twitter's latest moderation policy changes will lead to mass graves and white genocide any day.
HN post topics are restricted, usually to technical stories or less controversial political topics. Comments tend to be precisely worded, and are often more pedantic. Because of how linking works (or rather doesn't), citations often use a particular format. Comedy is generally discouraged, though is accepted more if (like in Traster's top-level comment in this thread) there's also "legitimate" point attached. If that comment hadn't included the second paragraph, it would probably have been downvoted. All of that is part of the culture of HN, and I wouldn't necessarily call any of it toxic. Some of it follows directly from the site rules and moderation, some follows from the technical limitations of the site, and some just emerges from the sorts of people who happen to use the site.
Either way, what’s being described is a process to refine materials to be used in space, where currently sending similar materials from the is prohibitively expensive.