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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

#71

Post by burnished »

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…

No, absolutely not. I can't say future space mining isn't a consideration (a moonshot if you will) but the challenges are astronomical. First you have to setup a mining and refining operation in an incredibly hostile environment and then you need to ship it back. We just aren't there yet.

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

#72

Post by joshuahedlund »

scoot wrote: post #3

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

In the book Super Volcanoes, I read about how complex the moon is geologically and how little of it we've examined and how poor our understanding of the geological history is. Apparently we can't yet explain how it was geologically active so recently. Imagine if the only rock samples we had from Earth were from a couple random spots on the surface, from wildly different time periods, and trying to develop together a theory of how its geology changed over time from that.

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

#74

Post by BurningFrog »

jandrese wrote: post #61
somenameforme wrote: post #30

Earlier quoted context omitted.

The moon is fairly unique (relative to Earth) in that the exact same spot will go from -200C to +100C on a two week cycle (day and night). It seems "obvious" that there must be some clever way to exploit this to generate energy in a simple and novel fashion.

I have always assumed that the first moon colony would be on the north or south pole to avoid this issue. Not too hard to imagine a solar array set up to track the sun with a very slow rotation. The colony itself would be in a crater to avoid direct sunlight and provide a place to dump the heat from the solar array. Otherwise the need to bring enormous power storage to handle the half month of darkness and bitter col…

Could you exploit the temperature differentials between the either hot or cold surface, and the presumably in-between temperature at the bottom of a drill hole?

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

#75

Post by jandrese »

BurningFrog wrote: post #74
jandrese wrote: post #61

Earlier quoted context omitted.

I have always assumed that the first moon colony would be on the north or south pole to avoid this issue. Not too hard to imagine a solar array set up to track the sun with a very slow rotation. The colony itself would be in a crater to avoid direct sunlight and provide a place to dump the heat from the solar array. Otherwise the need to bring enormous power storage to handle the half month of darkness and bitter col…

Could you exploit the temperature differentials between the either hot or cold surface, and the presumably in-between temperature at the bottom of a drill hole?

In theory the temperature underground should be the average of the surface temperature, so you could use that gradient to generate energy at night. Someone smarter than me would have to do the math on the energy density of a scheme like this, my gut says it's going to be fairly low and you will need a really big power plant to supply even a modest colony.

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

#76

Post by ianburrell »

rplnt wrote: post #16
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

It would likely be a thermal reactor, I guess? So no waste heat, since the little heat it gives is used to generate electricity.

Most nuclear reactors are thermal power plants and they all need to dump waste heat. Thermal power plants convert heat into electricity with turbines and are limited by dumping the waste heat.

Are you thinking of radioisotope generators? Those aren't reactors. They use thermocouples and need to get rid of the waste heat. The Voyager RTGs have radiator fins.

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

#77

Post by dctoedt »

pc86 wrote: post #55
JumpCrisscross wrote: post #34

Earlier quoted context omitted.

> it is impossible to know this without long term data which is simply not available Generating these data is one of the biggest pay-offs of a lunar colony.

I know data is the plural of datum but seeing "these data" instead of "the data" is always so jarring to me. Almost as jarring as seeming anyone use the word "datum" ever. Is this one of those generational things like "on accident" vs. "by accident" or regional things like "math" vs. "maths"?

> Is this one of those generational things like "on accident" vs. "by accident"

"On accident": Abomination! Kill it with fire, now!

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

#78

Post by Symmetry »

scoot wrote: post #3

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

I wonder if not being shielded by the Earth's magnetic field during full day would lead to a different balance of isotopes deposited by the solar wind.

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

#79

Post by squarefoot »

consumer451 wrote: post #20
creer wrote: post #15

Earlier quoted context omitted.

Perhaps? Any reason that sounds silly to you?

No, and this is not some attack on nuclear power. I am just curious. On earth, nuclear power plants use lots of water and cooling towers. How does that work in a place with no spare water? I also meant to write fission in my original question, not fusion.

> How does that work in a place with no spare water?

I wonder if recycling human liquid waste through evaporation could be of some use for that purpose.

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

#80

Post by standardUser »

Do either China or the US have plans to attempt a Mars sample return? Does China have the rocket power to attempt such a mission? The US seems focused solely on the return moon missions, with any Mars mission presumably behind at least 5 more major Artemis missions that are scheduled through 2031.
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