Viewing a single comment thread. View all comments

FlingingGoronGonads OP t1_j8s6scv wrote

> Nasa’s current research efforts for in-situ oxygen extraction is focused on “bottling” the oxygen in compressed gas tanks or to liquefy and store it in dewars, which are insulated containers used for storing cryogens. Either approach requires moving tanks or dewars to various facilities for use. The process of moving this oxygen on rovers could be more energy intensive than the extraction process itself and could be the most expensive aspect of obtaining in-situ oxygen for use on the Moon.

> For this design study, Lunar Resources and Wood will do a system-level design study of LSPoP. They will explore the feasibility of building pipeline elements on the Moon with the metals found there, which will be extracted using a process called molten regolith electrolysis (MRE) [my emphasis added]. Lunar regolith is the unconsolidated sand-like debris on the surface of the Moon. Full scale test systems of this process on Earth have successfully extracted high-purity iron, aluminum and silicon.

> The starting concept is for a 3.1-mile (five kilometer) pipeline to transport oxygen gas from an oxygen production source to an oxygen storage/liquification plant near a lunar base.

It's not clear to me why you would build essential infrastructure like O2 production at any significant distance from a habitat. Perhaps "pipeline" is giving me the wrong impression here, but I do know this - the same regolith or sources you are processing to extract the metals also give you O2 - silicate rock is not exactly low in oxygen.

The article is fairly informative, but does contain this bit of silliness:

> Extracting oxygen ice and other lunar materials is one thing. Transporting it around a rock floating in space with no gravity or atmosphere is a much more complicated task.

No gravity, huh? I hope the people involved in the study are a little sharper than the author of this piece...


invol713 t1_j8s7i64 wrote

It does seem unnecessary. Why not just build the base right next to your extraction site? That would make the most sense. Unless they think they are going to create sinkhole problems, in which case a pipeline is just a big straw waiting to be bent/snapped.


ragnarmcryan t1_j8sswxk wrote

Y’all might be thinking too short term. It might not be too close to the first site, but as time goes on, more of these things are planned I’m sure. This pipeline might be in the best place for a long term strategy


invol713 t1_j8supo9 wrote

That makes sense. It’s just taken so long to get this done that even the short term feels long term.


David_ungerer t1_j8sytl3 wrote

They first walked on the moon in July 16 1969 . . . I watched it live . . . Short term does feel long term ! ! !


Tre-Ursus t1_j8t21wm wrote

Mining's a messy business, and regolith is nasty stuff that sticks to everything. You're going to want to keep that far away from any sensitive equipment and people.


invol713 t1_j8uwtq9 wrote

Fair enough. It does make me wonder which is a worse environment for regolith mitigation… no atmosphere Moon, or light-atmosphere Mars?


FlingingGoronGonads OP t1_j8xg61d wrote

I'm not sure that we know enough about Martian regolith to answer that yet. We really need those samples Perseverance is collecting back here in the lab...


Tre-Ursus t1_j8v5yxx wrote

No atmosphere on the moon means weather doesn't blow it around like on Mars. But the moon is uniquely oxygen rich from circling the earth. The same technology won't be feasible on mars.


FlingingGoronGonads OP t1_j8xfvkw wrote

Oxygen production is quite a bit easier on Mars, as it turns out. We've already produced O2 from the CO2 atmosphere. That's a lot easier than importing oxygen from Earth or extracting it from Lunar rock, as per this NASA proposal.


Tre-Ursus t1_j8xmrjx wrote

The oxygen extracted from lunar rock is a byproduct. The main goal is the aluminum, iron, and silicon that's leftover.


miemcc t1_j8upacm wrote

The present thinking is that the oxygen will come from ice in deep pockets in crater walls at the Lunar South Pole - Specifically Shakleton Crater. Being near the pole gives near constant sunlight for the base and for the electrolysers.

If the O2 is generated in the crater, it will need to be moved to make it available for the Base and launchers. Initally that will be by rover. The aim of this research is to see how they can locally produce gas-tight pipelines from regolith


FlingingGoronGonads OP t1_j8xhgwo wrote

> The present thinking is that the oxygen will come from ice in deep pockets in crater walls at the Lunar South Pole

Based on this related article from NASA, my understanding is that the oxygen will be extracted directly from the regolith.

Given that they're already going to be processing the stuff to obtain the metals in the first place, that makes more sense than drawing O2 from the ice, and can be done at any old site on Luna, which is not the case if you're dependent on polar ice.


David_ungerer t1_j8syci5 wrote

It could be that mining/extraction creates a dust cloud . . . And that cloud is in some way dangerous to the habitat or launch equipment.


invol713 t1_j8t17rj wrote

How would a dust cloud work in no atmosphere?


David_ungerer t1_j8t7wwk wrote

Google moon dust problem . . . Yes it is a thing ! ! !

I decided to help you search . . . From the Apollo era it is known that dust on the Moon can cause serious problems for exploration activities. Such problems include adhering to clothing and equipment, reducing external visibility on landings, and causing difficulty to breathing and vision within the spacecraft [e.g. 1,2]. › pdfPDF IMPACT OF DUST ON LUNAR EXPLORATION - NASA

Low gravity is the problem ! ! !


jharrom t1_j8vot12 wrote

Low gravity and an almost complete vacuum are both huge challenges. Traditional construction of almost all structures on earth are engineered by necessity to compensate, use, and account for much stronger gravity. Add high-pressure liquefied gasses, huge temperature swings unlike anything on Earth, and the additional radiation. You not only have to build and run such a structure under those conditions, you have to use a ridiculous amount of safety precautions and redundant systems to guarantee the system won't fail catastrophically.


FlingingGoronGonads OP t1_j8xf4ud wrote

All true (though the proposal is for gaseous oxygen), which is why a long pipeline at the south polar site seems strange to me. Even if the O2 production must be done at a fair distance from the habitat, I'm wondering why it can't be buried in regolith over most of its length, which would partially mitigate some of the issues you mention, not to mention providing protection from meteorites.

OTOH, if you can learn to manage the issues you're identifying here at this site, you do open up a lot of the solar system (asteroids, moons of Mars, airless bodies generally)...


anti-torque t1_j8s8ogr wrote

>No gravity, huh? I hope the people involved in the study are a little sharper than the author of this piece...

It's written by an engineer, not an astronomer.

edit: Also, I imagine the movement of gaseous oxygen would only occur in 14 day spurts, with the following 14 days being optimal for liquid o2 to be piped.


miemcc t1_j8upr7e wrote

Not likely as they are looking at the Lunar Southern Pole for this. Almost constant sunshine.