Clean lithium fission rocket

[sanman]

Could you use this to augment thrust of a chemical rocket?

[Michel Van]

Could you use this to augment thrust of a chemical rocket?

Like in HydroLox engine ? No !

Even i you manage to mix Lithium-6 into liquid hydrogen
you need neutron source to trigger it and you get a engine that's heavy and i mean to heavy for any advantages.
and from proposals to use nuclear reactor to heat Chemical fuel
or use as Afterburner on Chemical engines failed like wise to heavy


so Lithium-6 in D20 is here best way for high thrust and exhaust speed.   
 

[sanman]

I'm a little boggled at how a system that expels masses of Tritium is considered "clean"?

Ok, no surplus Neutrons... BUT you need a ridiculously intense neutron source to activate it.
So, where exactly does this "clean" come in?

https://en.wikipedia.org/wiki/Nuclear_salt-water_rocket#Limitations

It's "clean" only in that it's cleaner than Zubrin's NSWR, which exhausts actively fissioning uranium/plutonium salts.

How about some other neutron-rich isotope, besides tritium? Tritium is less stable, and thus less "clean". But there are other neutron-rich isotopes which are more stable, even while having a larger nuclear cross-section, thus allowing more chance of collision to liberate more neutrons.

Do we take the definition of "clean" to mean less chemical toxicity, as well as less radioactive toxicity?
You'd want a stable isotope with a rapid decay chain, while not being overly reactive or a heavy metal.

What are the candidates meeting that definition?

[tea monster]

I came up with a concept for the vehicle described in the Atomic Rockets post by William Mook.
I was shocked at how big this thing was that could (theoretically) get several people to Jupiter.
He described it with an Orion-style pusher plate (without the shock absorbers).

[tea monster]

I worked up a slightly larger ship design. The glowwy red bits are radiators. I'm not sure if this design would require them, or if the heat would be carried away by the exhaust. There is an aeroshell form to the hull. At the apex of the vehicle is debris armour. Landing legs are built into the fins, though there is some debate as to whether you could safely land this engine anywhere without polluting the pad.

I modelled a version of the engine design that mlorrey came up with.

With this amount of delta V with this little vehicle mass, you could go 'full Sci-Fi' with your ship design. You could even bring a variant of the 1930's Flash Gordon space bus to life!

[Pete]

A layer of lithium-6 hydride deposited onto a beryllium bell nozzle and irradiated ...

The fuel is dissolved in water; the fuel is used to heat the water; the water and the fuel's reaction products are expelled together. Pretty simple.

You really need to make it more clear that you are talking about two **COMPLETELY DIFFERENT** systems here.
May I humbly suggest you start a new thread about this alternate system, rather than mutating your existing thread and confusing the poor readers?

[vasimv]

Just wondering, why not use pulsed mode for this? Like in https://en.wikipedia.org/wiki/Pulsed_nuclear_thermal_rocket but with solid lithium hydroxide (sheets/powder/wire/etc) or a solution in water injected instead hydrogen. This will reduce thrust a lot but will increase ISP and solve many problems - cooling reactor (neutron source) will be easier, much less meltdown chances. Even with only tens of newton thrust but high ISP this engine will be very useful for cargo transportation and such.