Do we have working prototypes of gas and liquid NTRs

[MC.STEEL]

I am digging for stuff on the Internet for a hard-ish sci-fi and cant help but notice the only engine that has real life pictures is the humble solid core.

The liquid core is only has very few schematics and gas core are only found in schematics and CGI renderings.

So what gives, did they cut funding before anyone made working prototypes or is the Internet really gone to hell and the only thing one is able to do with it is look for pictures of cats?

Edited April 6, 2014 by MC.STEEL

[SargeRho]

No, only the Solid Core NERVA prototype(s), and I think the Russians also built a Solid Core NTR. But Nuclear Lightbulb-type engines are pretty close to just needing to be built. I don't know how much engineering is left to do on those, but last I read, not much.

[Ralathon]

They never got past prototyping the solid core NTR before the government cut funding. Too much fear of radiation and everything nuclear among the general public.

So no, they never build a liquid or gas core NTR. There's some talk about reviving NERVAs for Mars missions, but unless the political climate changes drastically I don't see it happening.

[Kryten]

Only two NTR programs ever produced a prototype, the US Nerva and Soviet RD-0410; both were solid core. Only a few liquid-fuel reactors have been produced, all small research reactors, and gas-core designs are purely hypothetical.

[YourEverydayWaffle]

I believe there was one Soviet NTR that they got running for a very short time. It's very tough to make one work, due to the radiation levels required in the fission reactor to generate sufficient heat to heat hydrogen. It's just an inherently dangerous concept.

[MC.STEEL]

Well now i see, they just didnt get finished.

And even if the populace changes their irrational view about nuclear the gas core will still be problematic,as far as i read the fuel is IN the remass and some unburnt fuel is bound to escape.This will still frighten some people because thats how humanity rolls i guess.

[Ralathon]

I believe there was one Soviet NTR that they got running for a very short time. It's very tough to make one work, due to the radiation levels required in the fission reactor to generate sufficient heat to heat hydrogen. It's just an inherently dangerous concept.

The US had a working prototype as well. They ran it for a few hours in a vacuum chamber. Here's a video of an open atmosphere test:

They got an ISP of 900+ out of it. Really a shame that the project lost funding.