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posted by martyb on Friday June 18 2021, @11:53PM   Printer-friendly
from the moon-dust-is-very-abrasive dept.

Rocket Mining System Could Blast Ice from Lunar Craters

A mix of dust, rocks, and significant concentrations of water ice can be found inside permanently shaded lunar craters at the Moon's south pole. If that water ice can be extracted, it can be turned into breathable oxygen, rocket fuel, or water for thirsty astronauts. The extraction and purification of this dirty lunar ice is not an easy problem, and NASA is interested in creative solutions that can scale. The agency has launched a competition to solve this lunar ice mining challenge, and one of competitors thinks they can do it with a big robot, some powerful vacuums, and a rocket engine used like a drilling system. (It's what they call, brace yourself, their Resource Ore Concentrator using Kinetic Energy Targeted Mining—ROCKET M.)

This method disrupts lunar soil with a series of rocket plumes that fluidize ice regolith by exposing it to direct convective heating. It utilizes a 100 lbf rocket engine under a pressurized dome to enable deep cratering more than 2 meters below the lunar surface. During this process, ejecta from multiple rocket firings blasts up into the dome and gets funneled through a vacuum-like system that separates ice particles from the remaining dust and transports it into storage containers.

Unlike traditional mechanical excavators, the rocket mining approach would allow us to access frozen volatiles around boulders, breccia, basalt, and other obstacles. And most importantly, it's scalable and cost effective. Our system doesn't require heavy machinery or ongoing maintenance. The stored water can be electrolyzed as needed into oxygen and hydrogen utilizing solar energy to continue powering the rocket engine for more than 5 years of water excavation! This system would also allow us to rapidly excavate desiccated regolith layers that can be collected and used to develop additively manufactured structures.

[...] The Phase 1 winners are scheduled to be announced on August 13.


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  • (Score: 0) by Anonymous Coward on Friday June 18 2021, @11:59PM (1 child)

    by Anonymous Coward on Friday June 18 2021, @11:59PM (#1147181)

    Just issue every astronaut one of Musk's flamethrowers.

  • (Score: 3, Funny) by MIRV888 on Saturday June 19 2021, @12:50AM

    by MIRV888 (11376) on Saturday June 19 2021, @12:50AM (#1147190)

    That or cgi has to become way more convincing. This ain't the 60's.

  • (Score: 0, Flamebait) by Anonymous Coward on Saturday June 19 2021, @01:08AM (3 children)

    by Anonymous Coward on Saturday June 19 2021, @01:08AM (#1147193)

    Everyone chill the fuck out about the Moon and Mars. If you want to fix some real problems, figure out how to build underwater cities. That will be fucking useful if/when we go to the fucking Moon, my apes. Horse before motherfucking cart.

    • (Score: 1, Flamebait) by Runaway1956 on Saturday June 19 2021, @07:40AM

      by Runaway1956 (2926) Subscriber Badge on Saturday June 19 2021, @07:40AM (#1147261) Journal

      That's nice. You would rather further destroy our oceanic ecosystem, than take our toys out where no one, and nothing cares about us making a mess. The whales will appreciate your concern.

    • (Score: 0) by Anonymous Coward on Saturday June 19 2021, @01:09PM

      by Anonymous Coward on Saturday June 19 2021, @01:09PM (#1147284)

      I agree more or less along your arguments. The only self sustaining habitat that has been built for humans was done by Matt Damon. Underwater habitat is an excellent test for remote habitats, and it would probably usher in a whole new vista for exploration. But it isn't sexy like Mars, so it is deemed better to set up a doomed habitat on Mars, because we don't know what the fuck we're doing yet, than it is to advance the technology while continuing robotic exploration of other bodies. It will be quite the feat when a human sets foot on Mars, but it will be like Apollo in that it will quickly become "been there, done that" for a number of more decades until we figure out what we're doing.

    • (Score: 0) by Anonymous Coward on Saturday June 19 2021, @05:03PM

      by Anonymous Coward on Saturday June 19 2021, @05:03PM (#1147314)

      We already have underwater habitats, they are called ‘nuclear submarines’, and nobody likes living there

  • (Score: 2) by Immerman on Saturday June 19 2021, @03:57AM (6 children)

    by Immerman (3985) on Saturday June 19 2021, @03:57AM (#1147232)

    Rocket fuel requires carbon (unless you're using hydrogen rockets, which virtually nobody is because hydrogen is a bitch to store and work with). Without carbon, you've got nothing useful for the rockets that are actually positioned to dominate the (near) future of space flight.

    Meanwhile, oxygen is plentiful everywhere on the moon - lunar regolith is ~40% oxygen by mass, readily accessible using the electrolytic magma refineries developed by Sadoway for NASA, for exactly that purpose. They can even produce high-purity steel as a useful byproduct, and should be tunable to also produce aluminum, magnesium, and/or titanium in smaller quantities as the technology matures.. And for orbital refueling, oxygen alone is actually really useful: 80% of the Starship's propellant mass is oxygen, if they can get that from the moon, they only need 1/5th as many refueling flights from Earth to just bring methane - which is 75% carbon by mass.

    The value of lunar water is primarily *as* water, for ecological purposes.

    • (Score: 2) by Runaway1956 on Saturday June 19 2021, @07:37AM (2 children)

      by Runaway1956 (2926) Subscriber Badge on Saturday June 19 2021, @07:37AM (#1147260) Journal

      Isn't there carbon in the r̶e̶f̶u̶e̶l̶i̶n̶g̶ ̶b̶e̶l̶t̶ asteroid belt? Along with gigatons of ice? We seem to have a mental block against dragging stuff from where it is plentiful, to places where it is less plentiful. All the raw materials required for space exploration are right there, waiting for us to come get them. It's almost as if the aliens in 2001 [imdb.com] planned ahead to make things easy for us.

      • (Score: 0) by Anonymous Coward on Saturday June 19 2021, @08:17AM

        by Anonymous Coward on Saturday June 19 2021, @08:17AM (#1147264)

        Rocks close to us have likely lost most of their water and the ones out far enough to be cold enough to keep it are further than Mars. Once we have a Lunar rocket fuel production facility we'll be able to go mine the asteroids, and then we won't need the Lunar one anymore.

      • (Score: 2) by PiMuNu on Saturday June 19 2021, @04:51PM

        by PiMuNu (3823) on Saturday June 19 2021, @04:51PM (#1147311)

        > to places where it is less plentiful.

        What is the delta v required to move stuff from the asteroid belt to earth? How much fuel does it take? Fundamental inefficiency.

        I guess one can use an ion drive, so long as instantaneous thrust is not required (e.g. for launch).

    • (Score: 2) by PiMuNu on Saturday June 19 2021, @04:48PM (2 children)

      by PiMuNu (3823) on Saturday June 19 2021, @04:48PM (#1147309)

      Interestingly, apart from a few odd cases, lava on earth is almost all non-carbon based as well. The apparent abundance of carbon, I guess, comes from slow process of extracting trace amounts by living organisms and depositing in the crust?

      https://en.wikipedia.org/wiki/Lava#Composition [wikipedia.org]

      Carbonate volcano:

      https://www.sciencedaily.com/releases/2009/05/090506144317.htm [sciencedaily.com]

      • (Score: 2) by Immerman on Saturday June 19 2021, @06:20PM (1 child)

        by Immerman (3985) on Saturday June 19 2021, @06:20PM (#1147325)

        To be clear, the magma refinery doesn't require lunar magma - rather it works on ordinary lunar regolith that has been melted to make it more chemically responsive, in a manner very much like current aluminum refineries operate. It is actually a variation on the electrolytic steel refinery Sadoway developed for use on Earth, tweaked to operate on raw molten regolith rather than concentrated ores.

        It is interesting that carbon doesn't seem to commonly mineralize without biological involvement - perhaps because it's so chemically active? It does make me wonder where exactly all the carbon ends up on a rocky planet like the moon. Seems like the cold ones often have lots of carbon-rich liquids. And then you've got Venus that's buried in a deep CO2 atmosphere. Did the Moon's carbon get blown away as volatile gasses it had insufficient gravity and magnetosphere to hold on to? Or is it trapped in deposits deep underground?

        • (Score: 2) by PiMuNu on Sunday June 20 2021, @12:40PM

          by PiMuNu (3823) on Sunday June 20 2021, @12:40PM (#1147467)

          > To be clear, the magma refinery doesn't require lunar magma

          Thanks for the clarification - I assumed as much.

          It's interesting, it seems like the early atmosphere was CO2 until 2.5 billion years ago. Assuming the lava had same composition, I guess that means the Carbon was mostly in earth's atmosphere? I guess if the moon has the same set up, then as there is no atmosphere it has no carbon source.

          https://en.wikipedia.org/wiki/Great_Oxidation_Event [wikipedia.org]

          It makes sense chemically - for example limestone, when heated (as in earth's core, or early moon), breaks into CaO and CO2.

          https://en.wikipedia.org/wiki/Lime_kiln [wikipedia.org]

  • (Score: 1, Interesting) by Anonymous Coward on Saturday June 19 2021, @02:19PM (4 children)

    by Anonymous Coward on Saturday June 19 2021, @02:19PM (#1147292)

    Our system doesn't require heavy machinery or ongoing maintenance

    There's definitely nothing simpler or lower maintenance than rocket engines!

    Leaving aside the general uselessness of trying to establish a moon colony, it's probably not worth extracting the water unless it's right there on the surface or just below. Moon regolith contains lots of oxygen. It's not much harder to extract the oxygen from the dirt than from the water, and if you're mining you are going to be producing it as a byproduct. (And if you aren't mining, what are you even doing there?)

    Just ship methane up from Earth, combine with the Lunar oxygen, make whatever you need. These rockets are already powered by methane, so it's what they're already planning! There's just a much better way to do it!

    • (Score: 2) by Immerman on Saturday June 19 2021, @06:39PM (3 children)

      by Immerman (3985) on Saturday June 19 2021, @06:39PM (#1147331)

      I agree with everything else, but I get the feeling you're being sarcastic with

      >There's definitely nothing simpler or lower maintenance than rocket engines!

      And for certain kinds of engines that's actually true. Specifically solid rocket engines, which are pretty much just a rod of highly flammable fuel and oxidizer enclosed in a tube that can survive the stress, possibly with a rocket nozzle and bell to optimize the thrust generated. That basic technology spans everything from bottle rockets to model rocketry, to the solid boosters on the Space Shuttle (and many other orbital rockets)

      There's also solid-gas rockets that (typically) use a solid fuel and gaseous (or liquid) oxygen as the oxidizer to allow them to be throttled, shut down, and re-started. At the simplest you can simply bore a hole through your fuel rod and pump oxygen through it. There's some very cool videos on Youtube of such a thing done with clear nylon rod operating as both the fuel and containment vessel so that you can see the flame consuming it from the inside.

      Even fully liquid or gas rockets don't have to be significantly more complex, as hobbyist rocket engines around the world prove. Something like a SpaceX Raptor certainly is - but that's because they're chasing extremely high thrust-to-weight engines and extremely high specific impulse, which are absolutely essential for reaching Earth orbit with any semblance of efficiency, but unnecessary if you're only looking to produce a jet of hot gas for excavation purposes.

      • (Score: 0) by Anonymous Coward on Saturday June 19 2021, @08:36PM (2 children)

        by Anonymous Coward on Saturday June 19 2021, @08:36PM (#1147345)

        Fair enough. But from the summary, they're planning to split (some of) the water and use the resulting hydrogen as fuel. A fully restartable hydrogen fueled engine is definitely not on the simple end of the continuum, especially since it's supposed to blast a bunch of notoriously abrasive moon dirt all around itself.

        The fact that it's a low thrust engine that has moderate mass constraints (you still have to ship it from Earth, but it doesn't have to lift itself) probably helps, but it still seems like a long shot.

        • (Score: 2) by Immerman on Sunday June 20 2021, @03:05AM

          by Immerman (3985) on Sunday June 20 2021, @03:05AM (#1147398)

          At the simplest end, that's still just a matter of combining pre-pressurized hydrogen and oxygen in an ignition chamber (probably with a rocket bell). Doesn't have to be significantly more complicated than a propane grill, with no moving parts except the valves... which don't actually have to be anywhere near the engine.

        • (Score: 2) by deimtee on Sunday June 20 2021, @04:35AM

          by deimtee (3272) on Sunday June 20 2021, @04:35AM (#1147416) Journal

          Got to agree with Immerman here. Rockets are difficult because you need extreme precision to get high Isp.
          Hydrogen is difficult to handle because they store it as a liquid at just a few kelvin.
          Neither is true for the 'rocket' excavator. It's really just a big blowtorch and there is no reason you can't store the hydrogen as a gas in a big dumb tank and run a hose to your 'rocket'.

          --
          If you cough while drinking cheap red wine it really cleans out your sinuses.
  • (Score: 1) by AlphaSnail on Sunday June 20 2021, @02:31PM

    by AlphaSnail (5814) on Sunday June 20 2021, @02:31PM (#1147495)

    How do you generate a vacuum in a vacuum? That's the part that's got me scratching my head. I can see the vapor creating some small atmosphere that you could direct toward an opening but you wont be able to suck up anything without air to suck with.

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