Rocket Propellant from Lunar Soil

http://www.wickmanspacecraft.com/lsp.html

by vpribish • 9 years ago

72 42 9 years ago

sethrin6• 9 years ago

I feel like the difficulty of obtaining rocket fuel on a given rocky planet is equivalent to within the limits of napkin math. I've never heard a particularly convincing argument for using the Moon as a springboard to the wider universe as opposed to Mars or Venus. Perhaps someone could offer some correction.

sparky_z• 9 years ago

Not a rocket scientist, nor do I have any hard numbers, but off the top of my head the Moon has a much smaller gravity well than Mars or Venus. On Mars, you would waste much more fuel just getting back into orbit. And Venus is just comically toxic. We weren't even able to build a single probe that lasted more than a couple hours on the surface of Venus before corroding, much less a permanent settlement.

Also, the moon is only a few days of travel away, instead of months-to-years (so someone on a permanent base could be medically evacuated if they have a tricky tumor, say.)

taneq4• 9 years ago

The Moon's gravity well is smaller but, with no atmosphere, it's both much easier to escape, and much harder to land softly on. If anything, I'd guess our best bet is a propellant factory on the Moon, using a magnetic launcher to shoot the fuel into lunar orbit to supply an orbiting fuel station.

ChuckMcM2• 9 years ago

The lower gravity and lack of oxygen make launching things with maglev sleds into orbit feasible. There have been a number of studies of a launch rail with a reusable 'bucket' carrier that would be built along an incline for a suitable orbit. The bucket would be accelerated electromagnetically along the rail, imparting sufficient energy to put the contents of the bucket into orbit which would be circularized at apogee with a small rocket burn. The rail would be powered by an array of solar panels and batteries, or possibly a flywheel similarly to the way the EMALS[1] system was designed.

Landing is the challenge on the moon as there isn't anything to push against or dump energy into. I don't know if anyone has considered a space elevator, I expect keeping it in position would be a challenge given the orbital dynamics involved.

[1] https://en.wikipedia.org/wiki/Electromagnetic_Aircraft_Launc...

greglindahl• 9 years ago

Not only have people considered a lunar space elevator, but, you can actually build it with today's materials science: https://en.wikipedia.org/wiki/Lunar_space_elevator

Pica_soO3• 9 years ago

You could create a semi atmosphere- by Electrically Blowing Up Sand? Sort of like simulating Atmosphere with a shotgun blast?

baybal2• 9 years ago

For as long as ice is present on the moon, using it is a matter of melting it, filtering, and electrolyzing.

Moon is also a sure source of aluminium. Components can be shipped flatpacked to the moon, where they will be placed on locally produced aluminium "skeleton"

e12e2• 9 years ago

I wonder if it would be feasible to build a solar furnace capable of melting aluminium with focused sunlight - the light side must have pretty steady and strong incoming solar radiation, with no atmosphere?

wfunction3• 9 years ago

I've never heard a particularly convincing argument for using the Moon as a springboard to the wider universe as opposed to Venus

The mere fact that Venus has a thick CO2 atmosphere surrounding a surface with a temperature 872°F should be more than convincing, let alone the 90 atmosphere pressure and sulfuric acid clouds and all the other icing on the cake.

sethrin6• 9 years ago

You should read more about proposals for Venusian colonies before assuming that your knowledge of the subject is sufficient for discussion. No one is proposing to live on the surface, and the sulfuric acid is not a particularly large problem.

abecedarius• 9 years ago

Rotating tethers ought to be practical around the moon even with current materials: https://en.m.wikipedia.org/wiki/Momentum_exchange_tether#Cis...

52-6F-62• 9 years ago

I found Wickman's story pretty interesting! Thanks for posting.

There was a lot of interesting info on there besides this post. Ahem -- the post itself was really interesting -- reminds me of how little I know in spite of my interest in space. Gotta get on that!

curtis• 9 years ago

You may also find LANTR (LOX-Augmented Nuclear Thermal Rocket) interesting:

http://www.nss.org/settlement/moon/LANTR.html

LANTR is still assuming that hydrogen is supplied from earth, but it's performance as a rocket fuel is magnified by using it in a hybrid nuclear thermal/chemical rocket, where the the LOX is supplied from the moon.

Pica_soO3• 9 years ago

I wonder- if a planet continuously lost atmosphere of the aeons, shouldn't there be a small swirl of gas spiraling out from that planet?

If that is the case, wouldn't it be enough to have a ram-scoop satellite harvesting it?

sfifs3• 9 years ago

I assume you are talking about Mars? It's not in space in isolation. Solar wind has been blasting away the atmosphere for aeons. So it's probably intermingled with solar wind across the trail of the solar system.

Govindae2• 9 years ago

It's probably going to tend to collect on the heliopause, but there's a lot of surface area there.

And it's a pretty long ride out.

perilunar• 9 years ago

"aluminum powder in gelled LOX"

Sounds interesting. I wonder if a hybrid engine would work also. i.e. solid compressed aluminium powder with LOX.

Rocket Propellant from Lunar Soil

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