The Nuclear Salt Water Rocket - Possibly the Craziest Rocket Engine Ever Imagined.

The Nuclear Salt Water Rocket is a rocket engine concept that uses a rapid nuclear reaction in a Uranium salt dissolved in water to create a high thrust, high efficiency engine which eclipses the performance of any rocket engine ever designed. It's a concept originally presented by Robert Zubrin, which is appealing because it looks more scientifically plausable than many other futuristic propulsion concepts.

It's also scary on so many levels, using a propellent that has to be stabilized by specially designed tanks, and relies on managing a small nuclear explosion with power outputs of hundreds of gigawatts.

The original paper can be read here:

And Atomic Rockets has a section on the device:

The Kerbal mod version is available as part of Nertea's "Far Future Technologies":

[rocketsocks]

Fly S.A.F.E.: Surfing Atop Fisson Explosions

[christophertstone]

Engines, % C, and "No known reasons it wouldn't work" - What a time to be alive.

[i.k.]

"non-stop Chernobyl", "weapons grade uranium", "fly safe".
Welcome to the CIA watchlist, bois.

[stormhawk]

Honestly, at this point in history, THIS is the best engine we've got for REAL interplanetary travel.

[Hykje]

"How is the engine running?"
"Not great -not terrible."

[Joe-xqzu]

This thing somehow manages to be even more insane than the one where you ride a constant chain of nuclear explosions on top of a giant steel plate

[ac]

Kerbal Space Program 2 developers:
"Write that down, write that down!"

[andreibaciu]

"So you know what we've thought about?"
"Please don't tell me you want to use nukes as a propulsion method again"
"Oh no not nukes, we want to make a non-stop Chernobyl"

[huracan]

"I went to Jupiter and back in 6 months, riding a continuous chernobyl-like atomic bomb". There won't be a more badass quote, ever. Period.

[DeliveryMcGee]

Project Orion: "Let's throw megaton-class nuclear bombs out the back and literally blow this thing to Mars."
NSWR: "Hold my beer."

[Sinnistering]

"Open cycle nuclear reactor"
Well. This is it. Nothing will ever excite me as much as this. My ChE and NE nerding combine to this one horrendous, wonderful beast.

[robopenguin]

”A drive’s capability as a weapon is directly proportional to its capability as a drive”
- The Expanse

[TheAgamemnon]

- So, is this a great idea or a terrible idea?

- Yes

[yoearth]

"Non-stop Chernobyl" sounds like a perfect angle for the pitch to the investors.

[AstronomicalYT]

"900 times the energy of TNT"

Excellent

[jamesgates]

He says “Fly Safe” while describing his magic nuclear bomb Chernobyl flying carpet...

[faroncobb]

Having read Zubrin's paper, there seems to be a pretty obvious show stopper in this design. Zubrin goes to great lengths to explain how a critical mass could be maintained in the cylindrical part of the engine(plenum) due to the fact that water is basically incompressible and would maintain a steady flow rate. But then he wants almost all the actual fission to happen in the nozzle where the propellant is more spread out and is no longer a critical mass. Because uranium atoms only release a limited amount of neutrons when they split there is simply no way to generate enough neutrons in the plenum to split the required number of uranium atoms in the nozzle, and if you had enough uranium in the nozzle where the propellant is spreading out to maintain a critical mass the plenum would go up like a bomb. Also you cannot heat the water in the plenum enough to turn it into steam, because then you have to take gas laws into effect where increased temperature requires either higher pressure(which would result in the flow going the wrong way), or increased flow speed as you go down the plenum, resulting in the critical mass being lost and the chain reaction ending even before you get into the nozzle.

Because heavier molecules such as water and uranium require a much higher temperature than straight hydrogen molecules to reach the same ISP, I am extremely skeptical that any attempt to build this design could actually reach the ISP levels of a nuclear thermal rocket, never mind the tens to thousands of km/s exhaust velocities Zubrin speculates about. I would love to be proved wrong, but this design seems to be a classic case of using math to get answers to a different question than you are actually asking.

[colinkennedy]

"There's a more powerful version, where instead of using reactor grade Uranium it uses WEAPONS grade uranium"

Because of course there is.

[ekscalybur]

"Ruin your day"


Early interplanetary humanity is going to be *LIT*

[mikeedwards]

"Dr Von Braun, let me introduce Dr Strangelove. Oh, you've worked together before?"