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NASA Wants to Send Nuclear Rockets to the Moon and Mars
31–40 of 89 posts
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#32For the first time, period. Doesn’t look like we had one 60 years ago...
I don't have time to verify the video at the moment, but I believe this is them testing said engine 60 years ago:
https://www.youtube.com/watch?v=GmxPRCyR-Co
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#33this is great! check out project Orion https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#34Anyone else just get a JSON 404 page from this link? { statusCode: 404, error: "Not Found", message: "Not Found" }
I tried it just now and was able to see the article. On another note, why do they include the HTTP status code in the JSON body? Isn't it already present in the status line of the HTTP response?
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#35Anyone else just get a JSON 404 page from this link? { statusCode: 404, error: "Not Found", message: "Not Found" }
I tried it just now and was able to see the article. On another note, why do they include the HTTP status code in the JSON body? Isn't it already present in the status line of the HTTP response?
People using funky software stacks don't always have access to the status line information, so some APIs include the status in json.
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#36Earlier quoted context omitted.
Who said anything about uranium? There are elements with far more favorable decay paths. Short decay + using that decay too = pretty much a clean nuclear reactor.
Well, I'm no nuclear engineer but I'd hope that if you could make one of those that was light enough NASA would use that instead.
It's called an RTG, and they've been using them for decades.
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#37what happens at the end of such a trip, when the propellant is exhausted, and can no longer evaporatively cool the core? it has to contain enough propellant to come back to Earth orbit to refuel the propellant coolant? even if the core is throttled to its lowest levels, it will still produce heat in the vacuum of space? or will radiative cooling balance the remaining production of heat?
You do what you would on a terrestrial reactor, and shut down the reactor e.g. by using control rods, or pulling out fuel rods to shut down the chain reaction. These wouldn't be simple radiothermal devices, but proper actively managed reactor cores.
Having said that you absolutely would need active cooling even in a 'shut down' state, probably by circulating a cooling fluid to radiator fins. You might use the same fluid as the propellant or might not. In the former case sure, you wouldn't be able to use all of it as propellant.
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#38this is great! check out project Orion https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
It's much more likely to look like NERVA than Orion.
https://en.wikipedia.org/wiki/NERVA
These types of engines have already been run: https://www.youtube.com/watch?v=eDNX65d-FBY
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#39what happens at the end of such a trip, when the propellant is exhausted, and can no longer evaporatively cool the core? it has to contain enough propellant to come back to Earth orbit to refuel the propellant coolant? even if the core is throttled to its lowest levels, it will still produce heat in the vacuum of space? or will radiative cooling balance the remaining production of heat?
With a nuclear thermal rocket generally you do 90% of your burn all at once to maximize the Oberth effect then you shut down the reactor. But you've still got secondary decays going on for a while so you slowly use the remaining 10% of the propellant to cool the engine while getting a bit more thrust.
Re: NASA Wants to Send Nuclear Rockets to the Moon and Mars
#40Earlier quoted context omitted.
Um, uh, um, uh...where to start? "Mined" from where? How?
The moon's dust contains huge amounts of helium-3. Which apparently is an amazing power source. Also, why fission? We do have working fusion reactors. They are called hydrogen bombs. (The outer part, at least.) As long as you can keep the G forces low ...
> Which apparently is an amazing power source
Theoretically, for reactors we don't have.