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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

#121

Post by mLuby »

vkou wrote: post #118
camiller wrote: post #70

Earlier quoted context omitted.

"Very unlikely that we could do anything on Earth that would make Mars look like a better place to live. " Humanity: Hold my beer....

Runaway global warming or global thermonuclear war will still leave many parts of the Earth far more habitable then Mars. Even if the biosphere were to go to hell, it would still have an atmosphere, and a magnetic field. Fantasists have wildly impractical ideas for fixing the former on Mars, but nothing for the latter.

There is a solution to both, and it's not impractical: https://news.ycombinator.com/item?id=13796364

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#123

Post by yongjik »

MichaelMoser123 wrote: post #90
sp0ck wrote: post #2

It's about time. Engineering decisions shouldn't be made based of irrational fears of general population. If nuclear power plant is best option for space mission we should use it.

Irrational fears? What are the chances of the rocket launcher blowing up with the reactor? How would we compute the fallout range as a function of altitude of the blast?

According to Wikipedia, "some granites" contain 10 to 20 ppm of uranium, and the density of granite is about 2.65 g/cm^3. If a rocket contains 10t of pure uranium, that is the same amount of uranium in a cube made of uranium-rich (20 ppm) granite, each side about 57m long.

Now imagine how many such cubes would fit inside your favorite mountain.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#124

Post by trey-jones »

FLUX-YOU wrote: post #113
Robotbeat wrote: post #105

Earlier quoted context omitted.

> Before we can consider seeding terrestrial stations on Mars, we should consider seeding a communications net around Mars. We already do. > Once we have a half dozen satellites circling Mars... We already have half a dozen active satellites circling Mars: https://en.wikipedia.org/wiki/2001_Mars_Odyssey https://en.wikipedia.org/wiki/Mars_Express https://en.wikipedia.org/wiki/Mars_Reconnaissance_Orbiter https://en.wik…

> https://en.wikipedia.org/wiki/Electra_(radio) >Data rates up to 1 Mbit/s That's a bit of a problem. It only seems to be a relay for other spacecraft and small surface craft. Much more data will need to be exchanged between Earth/Mars when humans are involved (weather, video, entertainment, collected data, software, etc.) You'd probably want several brand new satellites dedicated to communications for an initial col…

If you think about the initial communications infrastructure around North America when Columbus set sail in the 15th century, we've got a leg up.

I realize it's not the same situation, not the same expectations, a different world than 500+ years ago, but real progress doesn't happen in a cleanroom.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#125

Post by [deleted] »

simias wrote: post #63
tehwalrus wrote: post #54

Earlier quoted context omitted.

I would say, given the state of politics and the general attitude to the climate and natural resources, our first priority should be colonising another planet. Putting some scientists on Mars for a few years is step 1 in that very important insurance scheme!

I don't know if I agree. Creating a self-sustainable colony on Mars will take a very long time and even if we manage to do it can we really afford to "lose" the earth? Mars is an inhospitable hell for humans and practical terraforming technology is still in the realm of science fiction. Maybe if we manage to destroy earth completely out of selfishness and hate we don't really deserve to spread the virus throughout th…

[deleted]

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#126

Post by mikeash »

FLUX-YOU wrote: post #113
Robotbeat wrote: post #105

Earlier quoted context omitted.

> Before we can consider seeding terrestrial stations on Mars, we should consider seeding a communications net around Mars. We already do. > Once we have a half dozen satellites circling Mars... We already have half a dozen active satellites circling Mars: https://en.wikipedia.org/wiki/2001_Mars_Odyssey https://en.wikipedia.org/wiki/Mars_Express https://en.wikipedia.org/wiki/Mars_Reconnaissance_Orbiter https://en.wik…

> https://en.wikipedia.org/wiki/Electra_(radio) >Data rates up to 1 Mbit/s That's a bit of a problem. It only seems to be a relay for other spacecraft and small surface craft. Much more data will need to be exchanged between Earth/Mars when humans are involved (weather, video, entertainment, collected data, software, etc.) You'd probably want several brand new satellites dedicated to communications for an initial col…

Once humans get involved, putting up a better communications satellite fleet should be trivial by comparison. You could almost just toss some satellites out the airlock before you start aerobraking. Obviously it would take a little more thought than that, but it certainly wouldn't be the hard part of the whole deal.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#127

Post by Horizon_Blue »

Before anybody asks "but what happens if the rocket blows up during launch": the reactor doesn't become significantly radioactive until after it's turned on. If anything it's quite a bit safer than the radioisotope thermoelectric generators currently in common use.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#128

Post by vkou »

sqeaky wrote: post #120
vkou wrote: post #99

Earlier quoted context omitted.

Yes, it would be.

The biggest problem to fixing earth is the people with politics that fly in the face of reality. Mars Doesn't have republicans, so I think it would be easier to terraform than earth.

Unless you're building better humans, we're going to have the exact same political problems on Mars that we do on Earth. Except in an environment where any small thing going wrong has the potential to kill everyone.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#129

Post by Retric »

londons_explore wrote: post #30
davedx wrote: post #22

Earlier quoted context omitted.

> 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 the…

Dumping heat into the ground is another option. But, generally keeping things warm is going to be a larger issue than keeping things cool unless they are producing crazy amounts of power. Further, the atmosphere might only be 1% of earth's but when the temperate averages -60C you can still use it to passively dump heat without needing vast radiators.

Re: NASA Revives Plan to Put Nuclear Reactors on Mars

#130

Post by logfromblammo »

vkou wrote: post #117
monocasa wrote: post #109

Earlier quoted context omitted.

> on the surface of mars Why? Wouldn't it be easier to bootstrap by mining asteroids, and manufacturing in micro gravity, then dropping nearly finished goods onto the planet? That'd also allow you to use the same bootstrapping infrastructure for several surface sites.

Why would you want to manufacture in microgravity? What are the practical advantages of this? I can't think of any, but I can think of a lot of disadvantages of this. Also, a Mars colony would require millions of tonnes of raw materials. You can only get that in-situ.

I think the largest problem in orbital manufacturing is actually rejection of waste heat. Otherwise, being able to run robots in an oxygen-free environment and move around large masses without conveyors sounds pretty good.
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