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NASA Revives Plan to Put Nuclear Reactors on Mars

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Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#21

Post by kobeya »

Ntrails wrote: post #16
mikejb wrote: post #6

Earlier quoted context omitted.

I agree. Though we might disagree on where legitimate concerns end and irrational fears start. It is also non-trivial to decide (and argue around) what a 'best option' is without defining a scale of what 'good' and 'bad' would be, and what factors are considered in that scale, and which ones are left out.

Can we start by agreeing on whether or not we care about a nuclear reactor going "pop" on mars pre-colonisation? Because, you know, there's a chunk of me that thinks we can be less risk averse in trying to do things on an uninhabited planet. Nuclear meltdown is pretty awful on earth, on Mars I don't see it with the same fear. I also feel like this is not dissimilar from dumping rubbish in the neighbours yard because…

The concern was never about a nuclear reactor having a failure mode on Mars. It was about the rocket carrying the nuke having a failure mode and spewing radioactive fuel over central Florida.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#22

Post by davedx »

Ntrails wrote: post #16
mikejb wrote: post #6

Earlier quoted context omitted.

I agree. Though we might disagree on where legitimate concerns end and irrational fears start. It is also non-trivial to decide (and argue around) what a 'best option' is without defining a scale of what 'good' and 'bad' would be, and what factors are considered in that scale, and which ones are left out.

Can we start by agreeing on whether or not we care about a nuclear reactor going "pop" on mars pre-colonisation? Because, you know, there's a chunk of me that thinks we can be less risk averse in trying to do things on an uninhabited planet. Nuclear meltdown is pretty awful on earth, on Mars I don't see it with the same fear. I also feel like this is not dissimilar from dumping rubbish in the neighbours yard because…

> uninhabited planet

By humans. By other life-forms is yet to be proven one way or another. There is already discussion of treaties to prevent contamination of any Mars biosphere by human missions there.

Also: what about the future? There's no point in sending a nuclear reactor to Mars if a future colonisation mission can't go ahead because the reactor has melted down...

Solar irradiance is approximately 50% less than on Earth. PV with high efficiency modules (the same ones they use on satellites) is also viable. I wonder if anyone has run the numbers on the cost of shipping a reactor Vs. the cost of shipping a football field of PV modules there.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#23

Post by cortexio »

8draco8 wrote: post #17
cortexio wrote: post #15

I'm getting kinda sick of the media putting more & more non-sense in our heads instead of actual news. This is pure fantasy. They can't build nuclear reactors on Mars! The only reason why they write this article is because the topic "Mars" generates large amounts of views. News shouldn't be a bussiness :(

Genuine question: If it's possible to use mini nuclear reactors in satellites then why they just can't land that thing somehow on Mars (like they did with Curiosity) and use it on planet surface to power lab?

Mini reactors are useless on Mars. The power they generate is waaay to low compared to the money that is needed to bring them there. Also putting nuclear reactors on sattelites almost never happens and is VERY DANGEROUS. It's what the Soviet Union did in the 70s-90s. The last sattelite launched with a nuclear reactor was in 1988.

You have to be pretty insane to launch large amounts of nuclear material from earth in a rocket that can randomly explode in our atmosphere.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#24

Post by petre »

cortexio wrote: post #15

I'm getting kinda sick of the media putting more & more non-sense in our heads instead of actual news. This is pure fantasy. They can't build nuclear reactors on Mars! The only reason why they write this article is because the topic "Mars" generates large amounts of views. News shouldn't be a bussiness :(

They don't have to build it on Mars. A kilowatt scale nuclear reactor is small and also safer and more portable. The Russians have already sent nuclear powered satellites into space.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#25

Post by cortexio »

petre wrote: post #24
cortexio wrote: post #15

I'm getting kinda sick of the media putting more & more non-sense in our heads instead of actual news. This is pure fantasy. They can't build nuclear reactors on Mars! The only reason why they write this article is because the topic "Mars" generates large amounts of views. News shouldn't be a bussiness :(

They don't have to build it on Mars. A kilowatt scale nuclear reactor is small and also safer and more portable. The Russians have already sent nuclear powered satellites into space.

Yeah, i used the wrong word there. I meant, "put" instead of "build"

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#26

Post by xorfish »

cortexio wrote: post #15

I'm getting kinda sick of the media putting more & more non-sense in our heads instead of actual news. This is pure fantasy. They can't build nuclear reactors on Mars! The only reason why they write this article is because the topic "Mars" generates large amounts of views. News shouldn't be a bussiness :(

> They can't build nuclear reactors on Mars!

That's why you build them on earth and transport them to mars.

There are some small designs such as the 4MW(el) u-battery that are small enough for a transport.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#27

Post by Retric »

davedx wrote: post #22
Ntrails wrote: post #16

Earlier quoted context omitted.

Can we start by agreeing on whether or not we care about a nuclear reactor going "pop" on mars pre-colonisation? Because, you know, there's a chunk of me that thinks we can be less risk averse in trying to do things on an uninhabited planet. Nuclear meltdown is pretty awful on earth, on Mars I don't see it with the same fear. I also feel like this is not dissimilar from dumping rubbish in the neighbours yard because…

> uninhabited planet By humans. By other life-forms is yet to be proven one way or another. There is already discussion of treaties to prevent contamination of any Mars biosphere by human missions there. Also: what about the future? There's no point in sending a nuclear reactor to Mars if a future colonisation mission can't go ahead because the reactor has melted down... Solar irradiance is approximately 50% less tha…

It's solar plus batteries which have been used for rovers for a long time, but simply weigh more and have a relatively short lifespan. Especially when you consider how useful 'waste' heat is on a planet that gets that cold.

As to contamination, it's a planet we did not abandon earth when Chernobyl melted down. Worst case nobody goes within 100 miles of it for a few decades. But frankly people are unlikely to go to 99% of Mars anytime soon and can't walk outside without significant protection anyway.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#28

Post by xorfish »

avar wrote: post #20
dredmorbius wrote: post #18

Earlier quoted context omitted.

Output, and fuels. Thermoisotopic generators generally rely on plutonium, which is in very low supply, and generate only about 100-200We output AFAIU. That's enough for electronics and comms on a deep-space mission, but doesn't offer a whole lot of surplus power for planetary activity. Among the reasons that lander craft are so slow-moving (they basically manage a slow crawl) is power demands, though other factors, i…

> plutonium, which is in very low supply. Thermoisotopic generators are a bad idea for general power generation for a colony for other reasons (they're low power, you need a lot of them), but it's not a problem that they're in low supply. That's just because we haven't been making more plutonium recently, because we haven't needed it. We could simply make more.

Pl-238 is very expensive to produce. We are talking millions/kg.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#29

Post by cortexio »

xorfish wrote: post #26
cortexio wrote: post #15

I'm getting kinda sick of the media putting more & more non-sense in our heads instead of actual news. This is pure fantasy. They can't build nuclear reactors on Mars! The only reason why they write this article is because the topic "Mars" generates large amounts of views. News shouldn't be a bussiness :(

> They can't build nuclear reactors on Mars! That's why you build them on earth and transport them to mars. There are some small designs such as the 4MW(el) u-battery that are small enough for a transport.

Read my 2 comments below. Sry for the confusion.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#30

Post by londons_explore »

davedx wrote: post #22
Ntrails wrote: post #16

Earlier quoted context omitted.

Can we start by agreeing on whether or not we care about a nuclear reactor going "pop" on mars pre-colonisation? Because, you know, there's a chunk of me that thinks we can be less risk averse in trying to do things on an uninhabited planet. Nuclear meltdown is pretty awful on earth, on Mars I don't see it with the same fear. I also feel like this is not dissimilar from dumping rubbish in the neighbours yard because…

> uninhabited planet By humans. By other life-forms is yet to be proven one way or another. There is already discussion of treaties to prevent contamination of any Mars biosphere by human missions there. Also: what about the future? There's no point in sending a nuclear reactor to Mars if a future colonisation mission can't go ahead because the reactor has melted down... Solar irradiance is approximately 50% less tha…

Installing/laying out a football field of modules sounds rather tricky, as does keeping them clean (mars is dusty and windy).

I assume the nuclear reactor would be a pretty much "sealed unit" which just needs to get rid of a lot of heat. There is no reliable water/evaporative cooling on mars, nor is the atmosphere thick enough for fans etc. to be effective. Instead it will need huge thermally emissive panels. For them to be effective, they need to be very hot.

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