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TerenceMulvaney t1_iv10t2j wrote

I'll save you a click. They aren't turning the regolith itself into fuel; they are using it as a catalyst to help crack CO2. Clever chemistry but not a miracle.

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GrandNibbles t1_iv13ua5 wrote

Still cool that the moon has been useful for the first time ever. Other than all the gravity shit it does

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Mad_Dizzle t1_iv1deno wrote

There's been a lot of research done with regolith applications because there's a big focus on "in-situ resource utilization" basically using what you can find in extraterrestrial habitats. The main applications from what I remember is regioith composites being used for construction, as well as processing the stuff to produce oxygen for habitats as well.

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danielravennest t1_iv5e1m1 wrote

I used to work at Boeing's space systems division.

Studies I worked on showed 98-99% of space projects could be built from materials already in space - from the Moon and nearby asteroids. The other 1-2% are either too rare to mine in space or too hard to make up there. It is just easier and cheaper to launch from Earth. This would vastly reduce how much you need to send from Earth, and lower the costs dramatically.

Simple products like water and bulk regolith would be first. Water as water and oxygen are needed for life support, and makes up a high percentage of rocket fuel. Bulk rock can be used for radiation, thermal, and impact shielding. Impacts come from micrometeorites and stuff kicked up by rocket exhaust.

Over time you can add other products, including making parts for your space factories. Then the factories themselves can grow without shipping them all from Earth.

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acksed t1_ivfou76 wrote

Further, use the sun and carbothermal chemistry for refining aluminium, both for construction and burning it in oxygen as a cheap rocket.

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NotAPreppie t1_iv16ymm wrote

I think the implied hope is that they'll find enough CO2 on the moon to use as feed stock to produce O2 and CH4. Just electrolyze some lunar water for the H2 and you'll have entirely in-situ rocket fuel synthesis with a side-helping of excess O2 for the ugly bags of mostly water to breathe.

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WaldenFont t1_iv19ek8 wrote

That line never sat right with me. An entity so alien that it refers to us by our molecular makeup has opinions on beauty?

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daneelthesane t1_iv1kcsg wrote

A crystaline mineral species would see us as disordered, which could be considered ugly. I have no issue with any intelligence having aesthetic values.

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NotAPreppie t1_iv19qim wrote

I'm happy to retcon that as a limitation of the Universal Translator system used on the Enterprise-D.

Or maybe it was just they think that baryonic matter in general is ugly.

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Scholesie09 t1_iv5ir11 wrote

If you saw a rock monster with an unpleasant face you could call it an ugly rock monster and it wouldn't be illogical.

It refers to humans as water based presumably because it's different to what they are, not because they are so advanced beyond the need for visuals.

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SpaceInMyBrain t1_iv3nxrv wrote

But the article references a study showing there is CO2 in lunar regolith, even though that wasn't the source of the CO2 used in this experiment. So, not too inaccurate for a news article. It's extremely unclear how abundant the CO2 is in regolith, or if that finding has ever been duplicated. I don't recall seeing NASA finding that in the many kilograms of regolith brought back by Apollo. Perhaps it's fairly deep and needed an impact blast to bring it to the surface. Hopefully not too deep to be accessible by some kind of strip mining.

If Starship is successful it will bring back lunar soils by the ton, so real progress can be made on this.

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AholeBrock t1_iv14ogw wrote

Too bad ya gotta advoid the moon monster to mine it

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CosmicDave t1_iv181ug wrote

NASA employee: oh hey u guys are back early

Astronaut: moon's haunted

NASA employee: what?

Astronaut: loading a pistol and getting back on the rocket-ship moon's haunted.

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brothermuffin t1_iv1hfnz wrote

You’re gonna flip when you find out we make computer from actual rocks

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GetsHighDoesMath t1_iv28xjq wrote

And then inject them with lightning to force them to think about stuff

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QueasyHouse t1_iv2g61t wrote

What’s so special about that? If I sat you down and forced lightning through you, you’d definitely be thinking about stuff

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stewartm0205 t1_iv17n0n wrote

You should be able to make hybrid rocket fuel by removing the oxygen from the regolith. Then burn the regolith with the removed oxygen to propel a rocket.

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danielravennest t1_iv5ewq3 wrote

That has pretty crappy performance.

The dark areas of the Moon (Maria) are made of basalt. Basalt fiber is only a little less strong than carbon fiber. Make an orbiting cable from the fiber and just pick up stuff from the Moon. The cable's orbit can be maintained using sunlight and electric propulsion. Oxygen extracted from lunar rock can be the fuel. Performance would be ten times higher than good rocket fuel and fifty times better than trying to burn oxygen with regolith slag.

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stewartm0205 t1_ivdazb0 wrote

A mass driver would be simpler and cheaper. You could fling cargo all the way to earth or Mars.

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danielravennest t1_iveia8n wrote

Electromagnetic catapults (mass drivers) are high peak power devices, since they have to do all the acceleration in a fraction of a second. Therefore they need a big power supply.

For example, getting to lunar orbit velocity over a 300 meter device takes 0.35 seconds. A 4 kg payload needs 5.78 MJ of kinetic energy, therefore 16.5 MW of power at perfect efficiency. If the mass driver is less than 100% efficient, input power needs to be higher.

A mechanical catapult with a rotating arm and electric motor can take as long as needed to come up to speed if it is operating in a vacuum. If you have an hour, the peak power is then 1.6 kW for the same payload. So it is better suited to low annual tonnage.

The original mass driver idea was for building space colonies, and launching half a million tons of material a year. At that kind of traffic rate you can justify the big power supply.

The orbiting cable approach doesn't put high g-forces on things like the other two. So you can carry people and complex equipment up and down. The catapults are suited for bulk materials. So which is better depends on what you are trying to do.

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stewartm0205 t1_ivvqxxz wrote

You can store the energy in capacitors or fly wheels. You biggest cost is the cost of shipping mass to the moon. You want to keep the mass of whatever you build to the minimum.

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danielravennest t1_ivz0io8 wrote

A rotating arm is a flywheel, just a straight rather than circular one.

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stewartm0205 t1_iwab8dd wrote

Have you calculate how heavy it would have to be?

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danielravennest t1_iwbr3xx wrote

For the Moon, the arm is about 6-8 times the payload mass. A complete system with drive motor and solar array is heavier. The figure of merit for these systems is the "Mass return ratio". That's how many tons of material delivered over their operating life, divided by tons of mining equipment, including catapults.

For a full discussion, see the Lunar Catapults section of my Space Systems Engineering book.

To verify authorship, click the View History tab on any page of the book and see the edits have the same user name as I have here.

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stewartm0205 t1_iwinued wrote

Total mass over lifetime. I would have liked to have seen a similar calculation for the linear system.

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danielravennest t1_iwlb1a7 wrote

The original space colony work by Gerard O'Neill and others assumed a "Mass Driver" (coilgun) which launched 4 kg lumps of lunar soil at 4 times a second, which amounts to 500,000 tons per year.

The gun would be 300 meters long and each payload takes 1/3 of a second to get up to speed. That means slightly more than one payload is in the gun at a time, and a near steady-state power supply.

Assuming perfect efficiency of the gun, it then requires 32 MW of constant electric power. With more realistic efficiency and running other stuff for mining or packaging the payloads, you are looking at 40 MW of power.

For comparison, this is in the range of a naval nuclear reactor, except you don't have the ocean to dump waste heat to. Current NASA work is towards 10-30 kW electric reactors for the Lunar suface. So factor of 1000 too small.

But such an electric catapult still needs 24 MW of peak power for launching single payloads at a lower rate. That's because all the acceleration happens over 1/3 of a second. So you need some kind of storage if your power source is smaller, and then release it in a burst.

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stewartm0205 t1_iwnntqj wrote

Solar panels and super capacitors should be enough.

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danielravennest t1_iv5cxdm wrote

"In-Situ Resource Utilization" (ISRU) is NASA's disguise name for "space mining". They disguise the name because certain reactionary members of Congress would lose their shit if they knew what NASA was planning.

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The_Solar_Oracle t1_iv5xbja wrote

ISRU typically means producing stuff for immediate use, rather then large scale extraction and export.

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Decronym t1_iv5denu wrote

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

|Fewer Letters|More Letters| |-------|---------|---| |H2|Molecular hydrogen| | |Second half of the year/month| |ISRU|In-Situ Resource Utilization| |KSP|Kerbal Space Program, the rocketry simulator|

^(3 acronyms in this thread; )^(the most compressed thread commented on today)^( has acronyms.)
^([Thread #8228 for this sub, first seen 5th Nov 2022, 13:04]) ^[FAQ] ^([Full list]) ^[Contact] ^([Source code])

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dailytour30 t1_iv6lpeb wrote

I bet one could make some real kickass concrete with some cement and that regolith stuff, if I understand its properties correctly.

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