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Chang'e 6 lunar sample return mission returns with samples from moon's far side

theguardian.com

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Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#41

Post by HenryBemis »

kkylin wrote: post #23
scoot wrote: post #3

What are they expecting to be different about samples from the moon's far side to those previously collected?

Leaving aside all the geopolitics and bragging rights, I would imagine that one scientifc reason for trying is that since the far side gets more meteor hits, there may be more material from elsewhere in the solar system. (Having said that I know nothing about this mission and am just guessing.)

I mentioned Gold on my comment before I read yours. Yes that makes perfect sense. Why ruin your reputation (hehe) with children mining rare metals, when you can have known and unknown rare metals flown in..

It is costly though to bring in a ton of from the moon.

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#42

Post by itishappy »

somenameforme wrote: post #22
krisoft wrote: post #5

Earlier quoted context omitted.

> Is there enough gravity on the moon to prevent the long-term health problems from the space station like bone, muscle and vision loss? Nobody knows. You might think scientist can science up answers to any question but it is impossible to know this without long term data which is simply not available. There were some experiments done in parabolic flights [2] but those only last for a very short time. There is this l…

Another, perhaps even more interesting question, is also how the first generation who are born in low g will evolve and adapt. And this, so far as I know, is a completely unexplored question. Mammal experiments might be interesting, but at some point you simply have to do it with humans, not only because of our fairly long gestation period, but also because of how absurdly undeveloped we are even once when born. Ther…

> And this, so far as I know, is a completely unexplored question.

To date, no mammals have given birth in space. We sent pregnant mice and had them return to Earth to give birth, and we've sent mouse zygotes and grown them in space, but no birth!

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#43

Post by dotnet00 »

JumpCrisscross wrote: post #35
throwaway199956 wrote: post #10

One thing they seems to have got working fairly reliably is the lunar landing of the probe using image processing to guide the final approach and touch down. It seems to have worked well in this and the previous mission, there are videos on youtube of that. https://youtu.be/wUju9-cckKA?si=nZFOCga10mnCA_vs The other component is the autonomous docking of the return probe in lunar orbit. Soviets have done a lunar sampl…

> the lunar landing of the probe using image processing to guide the final approach Anyone building precision weapons has gotten fairly good at this.

Weapons guidance systems get to be simpler in many ways.

If you've seen some of the Lunar or Martian landing videos, you'll notice that it's very hard to tell the scale. Especially on the Moon, the lack of atmosphere to disturb the surface makes it fractal-like, which probably really messes with the CV algorithm. It'd work fine when high up, but as you approach for landing, it would probably struggle, especially for, say, estimating how far away the surface is.

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#44

Post by dotnet00 »

consumer451 wrote: post #8
JumpCrisscross wrote: post #4

Earlier quoted context omitted.

> nuclear power plans by Russia not so much Why? Any lunar base without nuclear power plans is not a serious effort.

I often wondered, how do you deal with all the waste heat from a fission power reactor, in a vacuum? Giant radiators? edit: fixed typo, derp. fusion=fission

On the Moon you could also use the Moon itself as a heat sink. But yeah, any near-term solutions would use giant radiators.

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#45

Post by bluish29 »

HenryBemis wrote: post #40
scoot wrote: post #3

What are they expecting to be different about samples from the moon's far side to those previously collected?

I was thinking about "what have they found there?". I remember reading that the Central Bank of China was feversly buying Gold, and a few weeks ago they stopped all buying. Then this came to focus, and it made me think... did they find 100 tons of Gold up there, and they know that if they start bringing this in (on Earth) they price will plummet, and expect a massive sell-off in the next few weeks??? But then I do re…

I think it is very expensive way to acquire 100t of gold. It is cheaper to just buy or mine them from our planet.

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#46

Post by dotnet00 »

porphyra wrote: post #25
photochemsyn wrote: post #14

Earlier quoted context omitted.

Solar PV linked to battery storage is the obvious energy source for a moonbase. All reactors require coolant circulation and water is going to be among the most valuable commodities on the moon, not something you want to circulate through a reactor (where you inevitably get tritium formation, making the water unsuitable for other uses). Maybe you could use helium or liquid sodium metal as the primary coolant, but the…

You'll need an insane amount of battery storage, since the moon only rotates once per month and you'll need to power through a long period of no sunlight.

Or alternatively, for polar bases, very tall panels, which would be able to be in permanent sunlight.

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#47

Post by barelyauser »

dotnet00 wrote: post #43
JumpCrisscross wrote: post #35

Earlier quoted context omitted.

> the lunar landing of the probe using image processing to guide the final approach Anyone building precision weapons has gotten fairly good at this.

Weapons guidance systems get to be simpler in many ways. If you've seen some of the Lunar or Martian landing videos, you'll notice that it's very hard to tell the scale. Especially on the Moon, the lack of atmosphere to disturb the surface makes it fractal-like, which probably really messes with the CV algorithm. It'd work fine when high up, but as you approach for landing, it would probably struggle, especially for,…

Don't they use radar altimeters to get altitude? You don't need to rely only on image processing. You can even pull off stereo using a single camera since you are moving and know the altitude at every point.

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#49

Post by JumpCrisscross »

dotnet00 wrote: post #46
porphyra wrote: post #25

Earlier quoted context omitted.

You'll need an insane amount of battery storage, since the moon only rotates once per month and you'll need to power through a long period of no sunlight.

Or alternatively, for polar bases, very tall panels, which would be able to be in permanent sunlight.

> very tall panels, which would be able to be in permanent sunlight

Or normal panels on the rim of Shackleton [1]. (You'd still want to bootstrap with fission.)

[1] https://en.wikipedia.org/wiki/Shackleton_(crater)#Potential_...

Re: Chang'e 6 lunar sample return mission returns with samples from moon's far side

#50

Post by gus_massa »

dotnet00 wrote: post #44
consumer451 wrote: post #8

Earlier quoted context omitted.

I often wondered, how do you deal with all the waste heat from a fission power reactor, in a vacuum? Giant radiators? edit: fixed typo, derp. fusion=fission

On the Moon you could also use the Moon itself as a heat sink. But yeah, any near-term solutions would use giant radiators.

Solids don't conduct too much heat. I think most of the cooling in a nuclear plant is generated by evaporation of water.
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