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U.S. tests nuclear power system to sustain astronauts on Mars

reuters.com

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Re: U.S. tests nuclear power system to sustain astronauts on Mars

#51

Post by ahoka »

red75prime wrote: post #36
manmal wrote: post #29

Earlier quoted context omitted.

> the reactor can just be jettisoned before re-entering Earth‘s gravity well I think if there’s one thing to be learned from previous missions, it’s that nothing will „just work“. If the ejection mechanism is damaged, or the spacecraft is hit by some object and rendered useless shortly before ejection, then the radioactive payload will make it to Earth. I think a roundtrip would be dangerous, and the core should be l…

The political fallout will probably be more dangerous than adding another kilowatt-class nuclear reactor to decaying megawatt-class ones on sunken submarines.

This actually happened in the past. A Russian radar satellite failed to eject its nuclear reactor to a safe parking orbit and fell in Canada instead.

https://en.wikipedia.org/wiki/Kosmos_954

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#52

Post by 7952 »

icelancer wrote: post #45
lmilcin wrote: post #42

I am not sure this is a good idea. Nuclear reactor is an easy way out of a problem that has alternative solutions. Restriction on using nuclear power for previous missions did a lot of good in terms of researching and perfecting the alternatives (solar arrays). Restricting the use of nuclear power does not prevent missions, it only adds to the cost of the mission, which is not really a technical problem. Maybe launch…

There is essentially no actual ecological or serious fear about these devices. The weapons ban was meant to help avoid nuclear exchange between nations; there's very little scientific data that shows there's added cost or risk of thousands of reactors falling to Earth and causing radiation poisoning. Nuclear is exceptionally safe and all the recent accidents (and ones in the past, really) are all due to human stupidi…

> It's a human issue.

Which could be applied to any challenge that humanity face. This basic human weaknesses is always what holds us back in any endeavour. It is dangerous to just dismiss it as "arbitary". You have to deal with these issues if you want to make big projects achieve their objectives.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#53

Post by lmilcin »

DangerousPie wrote: post #48
lmilcin wrote: post #42

I am not sure this is a good idea. Nuclear reactor is an easy way out of a problem that has alternative solutions. Restriction on using nuclear power for previous missions did a lot of good in terms of researching and perfecting the alternatives (solar arrays). Restricting the use of nuclear power does not prevent missions, it only adds to the cost of the mission, which is not really a technical problem. Maybe launch…

I'm not sure I am convinced by this argument. You say it "only adds to the cost of the mission" as if that wasn't an issue, but unfortunately our resources are finite. If we increase the cost of any given mission that means we cannot do other missions. There is always a trade-off here, and I am not sure if the advantages of solar would be worth the cost of holding back research that much. You could easily make the op…

Nuclear reactors that have some service time on them are very, very, very radioactive. Just look what happens when a very small portion of that radioactivity finds itself into the atmosphere or water (Chernobyl, Fukushima, etc.)

It is maybe not as big a problem if we never plan it to return to Earth or Mars orbit (reactor is not as radioactive until it actually is started), but if we are using it to supply energy to the crew for the duration of the mission in deep space, the reactor will inevitably be radiactive and brought at least to Mars orbit or even back to Earth orbit.

Now, if that piece of junk falls to Earth, we have a big problem. Not the same kind of problem as falling solar array.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#54

Post by lmilcin »

icelancer wrote: post #45
lmilcin wrote: post #42

I am not sure this is a good idea. Nuclear reactor is an easy way out of a problem that has alternative solutions. Restriction on using nuclear power for previous missions did a lot of good in terms of researching and perfecting the alternatives (solar arrays). Restricting the use of nuclear power does not prevent missions, it only adds to the cost of the mission, which is not really a technical problem. Maybe launch…

There is essentially no actual ecological or serious fear about these devices. The weapons ban was meant to help avoid nuclear exchange between nations; there's very little scientific data that shows there's added cost or risk of thousands of reactors falling to Earth and causing radiation poisoning. Nuclear is exceptionally safe and all the recent accidents (and ones in the past, really) are all due to human stupidi…

Hi, just to point out a hole in your reasoning, if these reactors are so safe then why even a small portion of the radioactivity escaping the containment shell can cause such a big disaster like Fukushima or Chernobyl?

Now, I understand there are differences in size and the level of radioactivity used (they won't be driven as close to prompt criticality as the power reactors) and they may be designed to be less reliant on active protection (pushing a lot of water as required means to prevent disaster).

But still, this is radioactive material in Earth orbit where stuff tends to fall back after some time and we don't always control when and where it reaches us.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#55

Post by jacobush »

acidburnNSA wrote: post #18
vadimberman wrote: post #15

I'm curious, where does one get the nuclear fuel on Mars? Does it have to be flown all the way from the Earth?

Definitely. You can probably mine uranium on Mars but that would require a bunch of infrastructure and other power sources. These babys are way down-rated so they can run on a single loading of fuel for decades, like nuclear submarines. Good old E=MC^2.

I don't think there is any uranium to be had there. For such heavy elements to get deposited in ore near the surface takes special circumstances, such as those of Earth.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#57

Post by ageofwant »

lmilcin wrote: post #42

I am not sure this is a good idea. Nuclear reactor is an easy way out of a problem that has alternative solutions. Restriction on using nuclear power for previous missions did a lot of good in terms of researching and perfecting the alternatives (solar arrays). Restricting the use of nuclear power does not prevent missions, it only adds to the cost of the mission, which is not really a technical problem. Maybe launch…

The use of nuclear power should be encouraged and popularised whenever we can. Years of nuclear FUD needs to be unwound and humanity re-educated on the benefits of nuclear power. So much of our current climate change predicament could have been avoided. Its a crying shame.

https://www.youtube.com/watch?v=ciStnd9Y2ak

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#58

Post by ageofwant »

lmilcin wrote: post #53
DangerousPie wrote: post #48

Earlier quoted context omitted.

I'm not sure I am convinced by this argument. You say it "only adds to the cost of the mission" as if that wasn't an issue, but unfortunately our resources are finite. If we increase the cost of any given mission that means we cannot do other missions. There is always a trade-off here, and I am not sure if the advantages of solar would be worth the cost of holding back research that much. You could easily make the op…

Nuclear reactors that have some service time on them are very, very, very radioactive. Just look what happens when a very small portion of that radioactivity finds itself into the atmosphere or water (Chernobyl, Fukushima, etc.) It is maybe not as big a problem if we never plan it to return to Earth or Mars orbit (reactor is not as radioactive until it actually is started), but if we are using it to supply energy to…

Exactly what do you think "happens" ?

Not even Chernobyl, that had an atmospheric nuclear fire, the worst case scenario imaginable, had a economic, environmental or human live cost comparable to the impact of a single coal power plant.

It really concerns me when people on this forum, that has no excuse to not know better, parrots this anti-nuclear FUD.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#59

Post by jonathanstrange »

scrollaway wrote: post #49
jonathanstrange wrote: post #47

Earlier quoted context omitted.

Modern nuclear power plants are relatively safe. However, there is not enough data to determine how safe nuclear power is in general, because you have to take into account the whole production cycle including all long-term storage of nuclear waste. Half life time of nuclear waste ranges from 30 years to 24,000 years, so it's possible that hundreds of people die in 30,000 years from now by being exposed to nuclear was…

If you're taking that kind of thing into account you need to take the same time range into account in other power sources. How many hundreds of billions of people will die over the next 30000 years from coal effects? How does that compare to your 'hundreds'?

I completely agree and don't think coal is better than nuclear power at all. Reduction of energy waste, renewable energy sources and nuclear fushion are the obvious way to go, but it may make sense to temporarily accompany them with nuclear power.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#60

Post by fb03 »

rangibaby wrote: post #27
QuarterReptile wrote: post #12

Earlier quoted context omitted.

In Japan they just call them 'thermal plants' or 'thermal generators' or something like that. Still, in Japan you have people who follow around US aircraft carriers and submarines to sample their wake for any signs of radioactive discharge.

I haven't heard that before. 原子力(atomic, using atoms)+発電所(power plant) is the common term eg 福島(Fukushima)第一(No. 1)原子力(nuclear)発電所(power plant)

Gen-shi-ryoku Hatsu-den-sho? Let's see if I got it right, my Japanese is a bit rusty.

I am not sure about the readings of the first two kanji (atomic) so I used generic ones heehe.

Thanks in advance.

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