Space tech: Nuclear power off-Earth?

Hnau

Banned
Were there ever any plans to provide a space station, moonbase or Mars base with nuclear power? I know that both the American and Soviet space programs were planning on building nuclear rockets, especially for interplanetary voyages, but do we know of whether they were planning on putting nuclear reactors up in space just for the purpose of supporting human life?

It seems like this would be an essential component of any space colony. I mean, I guess you could go with solar energy on the Moon or Mars but it seems it would be much easier to provide electricity through a nuclear reactor. That makes me wonder how many personnel would have been required to manage even a miniaturized nuclear power plant...
 
Were there ever any plans to provide a space station, moonbase or Mars base with nuclear power? I know that both the American and Soviet space programs were planning on building nuclear rockets, especially for interplanetary voyages, but do we know of whether they were planning on putting nuclear reactors up in space just for the purpose of supporting human life?

It seems like this would be an essential component of any space colony. I mean, I guess you could go with solar energy on the Moon or Mars but it seems it would be much easier to provide electricity through a nuclear reactor. That makes me wonder how many personnel would have been required to manage even a miniaturized nuclear power plant...

The Apollo missions had radioisotope generators for power supply. They didn't actually bring solar panels for the Lunar Surface experiments. Many serious plans for manned Mars missions involve a nuclear reactor. The Russians got as far as testing the Topaz reactors on orbit--only a few kilowatts, but it's a start.
 
Yes. Many. Check out the American SNAP series of test flights, such as SNAP-10. Many nuclear-powered bases and such have been studied over the past 60 years or so, but they all eventually get shut down by the unrelenting public knee-jerk reaction of panic over launching a nuke into space, even as a reactor for exploration, not a bomb.

EIT: Also, as Polish Eagle mentions, there were many missions that used nuclear thermal generators--generating a trickle of power from the heat of a small nuclear sample decaying. About a dozen kilograms of nuclear material are on their way to Mars on the Mars Science Laboratory rover Curioisty, and there's others about Cassini, all the Voyagers, all the Pioneers, and a few others. Galileo also used on, and in fact is one reason the delays from the Challenger disaster were so bad--as the amount of nuclear material falls off due to radioactive decay, the power output falls as well. Galileo ended up having to operate only certain instruments at a time to power all of them due to losing the best years of its power source waiting for launch.
 
Tons of 'em, basically every plan before 1980 and most plans after, at least if you're planning to go out-system. And the Russians didn't just test reactors, they flew a bunch of 'em on RADAR mapping satellites. One accidentally reentered and burned up over Canada, too.
 
Well Nasa has used Radioisotope Thermoelectric Generators (RTGS for short) to power a few space probes. There was also a few actual reactors sent up, the American one called the SNAP-10A, while the Russian Program was known, strangely enough, as US-A.
 
Well Nasa has used Radioisotope Thermoelectric Generators (RTGS for short) to power a few space probes. There was also a few actual reactors sent up, the American one called the SNAP-10A, while the Russian Program was known, strangely enough, as US-A.

Heh, reminds me of something I read about a NASA program for a mission module whose acronym became "MOM." An official remarked that they didn't think they could find a politician who would vote against funding for MOM.

I suppose the Russians thought that no Americans would dare suspect the US-A of wrongdoing.
 

Hnau

Banned
Oh, wow, I didn't realize that there was so much experimentation with this in OTL! Neat.
 
Tons of 'em, basically every plan before 1980 and most plans after, at least if you're planning to go out-system. And the Russians didn't just test reactors, they flew a bunch of 'em on RADAR mapping satellites. One accidentally reentered and burned up over Canada, too.
Cosmos 954. That number is engraved in (many) Canadians' minds.
 
Yeah, it's another area in spaceflight where progress beyond the basics is governed much more by political support than by technical realities--though actually, as solar gets better, the advantages may decline--it's already quite a bit more mass-effective to do solar in Earth orbit compared to RTGs. The best panels make about 300W/kg, compared to about 3W/kg for RTGs. Since solar insolation falls out with the square of distance, this means solar now offers better power per kg for anything under 10 AU. Basically, anything within the orbit of Saturn. solar does require operational compromises--a 200W RTG is physically smaller than a 200W solar array, and doesn't need to deploy, or need batteries for when the sun isn't up on the surface of Mars or the Moon or whatever.
 
RTG has already been mentioned. I'd like to add that standard reactors require a lot of water, while the RTG does not.

NASA won't do it on the moon, because their number one concern is their own image, and the public will freak out when they hear anything nuclear. "Oh heavens, think of the radiation, think of the disaster if it melted down. Oh the environment!" Yeah... because there already is absolutely zero radiation on the surface of Luna at this moment.
 
RTG has already been mentioned. I'd like to add that standard reactors require a lot of water, while the RTG does not.

NASA won't do it on the moon, because their number one concern is their own image, and the public will freak out when they hear anything nuclear. "Oh heavens, think of the radiation, think of the disaster if it melted down. Oh the environment!" Yeah... because there already is absolutely zero radiation on the surface of Luna at this moment.

The TOPAZ and other designs used/would-have-used sodium or lithium. Radioisotope Thermoelectric Generators were used on the Apollo missions. The SP-100 program was inaugurated to serve as a nuclear electric propulsion system, and as a lunar base power source.
 
RTG has already been mentioned. I'd like to add that standard reactors require a lot of water, while the RTG does not.

Most - in fact, I think all - space-borne nuclear power systems use liquid metal coolants, not water.

Edit to Add: The SAFE uses gaseous coolants, as well, as do the various bimodal NTR proposals.

NASA won't do it on the moon, because their number one concern is their own image, and the public will freak out when they hear anything nuclear. "Oh heavens, think of the radiation, think of the disaster if it melted down. Oh the environment!" Yeah... because there already is absolutely zero radiation on the surface of Luna at this moment.

I believe the public's concern would more likely be that the rocket might blow up during launch. The consequences wouldn't be as severe as the public might fear - if the reactor hasn't started up yet then there's no fission products to be dispersed, and most of these are pretty small reactors, with correspondingly less material inside them. But it's not an unreasonable concern on the face of it.
 
Most - in fact, I think all - space-borne nuclear power systems use liquid metal coolants, not water.

Edit to Add: The SAFE uses gaseous coolants, as well, as do the various bimodal NTR proposals.

My concern over such a system (on Earth, not in space, so I guess it's drifting off topic) is that metal has a higher melting point than water. Which means lead freezes sooner than water. Of course, if water molecules get too hot, the reactor could explode. Didn't a couple of Soviet submarines have problems with this.. er the lead freezing in the works not the water vapor blowing it up? I suppose on Venus, liquid lead would not be as difficult to work with.
 
My concern over such a system (on Earth, not in space, so I guess it's drifting off topic) is that metal has a higher melting point than water. Which means lead freezes sooner than water. Of course, if water molecules get too hot, the reactor could explode. Didn't a couple of Soviet submarines have problems with this.. er the lead freezing in the works not the water vapor blowing it up? I suppose on Venus, liquid lead would not be as difficult to work with.

Yep. But it's a problem that can probably be overcome if we need liquid-metal-cooled reactors for some reason. And if you use a lead-bismuth eutectic, the melting point is only about 250 F.

My big concern with liquid-metal-cooled reactors is that the coolants are either flammable (sodium, NaK) or toxic (lead, Pb-Bi). All in all, we probably have better options, at least on Earth.
 
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One major advantage of liquid metal coolants is that they can be used at much higher coolant temperatures than water-cooled systems. Hotter coolant temperatures allow smaller radiators for the waste heat, as the energy that can be radiated per unit area goes up with the fourth power of the temperature. Thus, an increase of "hot" temperature by a mere 50% can up the radiator effectiveness by a factor of five.
 
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