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The US government is taking a step toward space-based nuclear propulsion

arstechnica.com

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Re: The US government is taking a step toward space-based nuclear propulsion

#181
post #70

Earlier quoted context omitted.

> Cold war = rocket science, new fuels, materials science, major computing advancements, supply chain changes, innovation, science hype, broad optimism Next time the cold war cools down, we need to invent something to replace it.

They tried with the war on terror, but it just wasn't the same thing.

That one was about oil.

Re: The US government is taking a step toward space-based nuclear propulsion

#182
post #73

Earlier quoted context omitted.

One thing I learned from the outside, the US - like any large country, BTW - is wildly diverse in pretty much every aspect.

It's almost intuitive if you consider the distance from Bangor to LA is pretty much the same distance as Madrid to Moscow. Think of the diversity between Madrid and Moscow. Bangor to LA won't take you through an equal amount of diverse cultures, the US is a single country after all, but the diversity is certainly there.

Not that intuitive, as the country has a language in common and one can simply drive from Bangor to LA without any local government asking questions. I have the impression cultural differences spring more from the economic and educational ones, unlike Madrid and Moscow, which have very long histories that are almost completely disconnected for most of that time.

Re: The US government is taking a step toward space-based nuclear propulsion

#183

Earlier quoted context omitted.

Rockets don't work with H2 alone.

H alone is the propellant in a nuclear rocket. H needs an oxidizer to explode. No oxidizer, no explosion.

So, you are agreeing with me?

Re: The US government is taking a step toward space-based nuclear propulsion

#184
post #28
post #8

Earlier quoted context omitted.

That’s an odd thing to say. Almost as if you’re in favour of nuclear for nuclear’s sake? Plenty of people have reasonable reservations about use of nuclear, not least the social /political ones of where to store waste that are still mostly unsolved. Blasting fission cores into space on rockets with fairly high failure rates in absolute terms seems like a fairly fine balance to strike?

Probably depends on your risk profile. Do we find new ways to safely generate energy using nuclear, or slowly cook ourselves alive on the planet's surface? Or to put it another way, at what point should we throw a Hail Mary in the energy demand game?

People here tend to run to extremes when they disagree with something. I am not here to detail out every individual practical application for nuclear energy; I am also not here to say where it should be avoided. Something something naysayers have a problem for every solution.

There is and has been a anti-nuclear sentiment when it comes to energy written in media for quite a few years and seeing that sentiment be turned around is positive. I am convinced(and it's just an opinion) the negative portrayal of nuclear energy is directly related to the financial influence that oil and other energies have over many sectors of the economy and government.

Re: The US government is taking a step toward space-based nuclear propulsion

#185

For anyone who wants a refresher on the UNS nuclear thermal rocket propulsion program from the '60s, here's the final report. It's a very good read: https://ntrs.nasa.gov/api/citations/19920005899/downloads/19... For this new initiative, I can see 2 big differences. On one hand they will use medium enriched uranium (up to 20%), while the original program used highly enriched one (85%), so it's going to be more challe…

Why are they nerfing the uranium like that?

85% enriched is bomb material, and also dramatically more expensive than 20% enriched.

No-one wants the extra work that dealing in bomb materials would involve.

Re: The US government is taking a step toward space-based nuclear propulsion

#186

This might be a good time to review the number of failed rocket launches we've seen in the last few years. Now, imagine them with nuclear materials aboard.

Uranium that has not been in a reactor is almost nonradioactive and inert. It only gets spicy after you let it go critical for a while, and fission products accumulate.

Any reasonable nuclear-powered craft would not start up the reactor until it's already in a nice, safe, high orbit.

Re: The US government is taking a step toward space-based nuclear propulsion

#187
post #8

Earlier quoted context omitted.

That’s an odd thing to say. Almost as if you’re in favour of nuclear for nuclear’s sake? Plenty of people have reasonable reservations about use of nuclear, not least the social /political ones of where to store waste that are still mostly unsolved. Blasting fission cores into space on rockets with fairly high failure rates in absolute terms seems like a fairly fine balance to strike?

You don't need to store nuclear waste, since you can burn it up in some fuel cycles. Essentially all the problems of nuclear power on the ground are political issues -- entrenched interests, weapons proliferation, and so forth -- not technological ones like safer reactors and nuclear waste.

That really does hand wave away a lot of important details. Those problems on the ground are the reason I am generally not pro nuclear… not because intrinsically I think it’s a bad idea to split atoms.
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