Helium-3 as nuclear fuel for Nuclear Rockets

[Triton]

If the lunar regolith is ever mined for Helium-3, could it ever be used as the nuclear fuel for nuclear rocket engines? Could this solve the radiation problem associated with nuclear rocket engine designs like the Nuclear Thermal Rocket (NTR) engine aka NERVA?

 

[Lauge]

If the lunar regolith is ever mined for Helium-3, could it ever be used as the nuclear fuel for nuclear rocket engines?

Yes, in a fusion engine, Helium3 would make an pretty decent fuel. According to http://www.projectrho.com/rocket/rocket3c2.html#he3dfusion: "He3-D Fusion: Fuel is helium3 and deuterium. Propellant is hydrogen. 1 atom of Deuterium fuses with 1 atom of Helium-3 to produce 18.35 MeV of energy. One gigawatt of power requires burning a mere 0.00285 grams of 3He-D fuel per second." Note the distinction between fuel (that supplies the energy) and propellant (the stuff heated by the fuel and thrown out the back to produce thrust).
Fusion is inherently "cleaner" than fission, but you still get some free neutrons that you have to shield against.

Could this solve the radiation problem associated with nuclear rocket engine designs like the Nuclear Thermal Rocket (NTR) engine aka NERVA?

No dice, since the NERVA and other NTR's are fission engines, using uranium, plutonium, thorium or some such as fuel.

Personally, I consider He3 to be one of the more promising fusion fuels for spacecraft. The only problem is finding it, and here the Lunar regolith is indeed a good bet.

Regards & all,

Thomas L. Nielsen
Denmark

Regards

 

[Michel Van]

Helium3 and Deuterium fusion has anthoer advance:
No Neutrons !
means you don't need heavy shield against Neutron
(other type of Fusion like Hydrogen + Hydrogen produce dangerous Neutrons)

to NTR and NERVA
see it as a Boiler, how used plutonium to heat liquid hydrogene

in this analog a Fusion engine is then more of a Plasma torch.

 

[starviking]

If I recall correctly Helium 3 was the fuel of choice for the British Interplanetary Society's Daedalus Interstellar Probe. Pellets of He3 were ignited by laser to propel the probe.

 

[KJ_Lesnick]

That's actually the kind of fusion used in the sun. Two helium-3's ram together, produce a helium-4 and two protons.

KJ Lesnick

 

[Simon666]

Helium3 and Deuterium fusion has anthoer advance:
No Neutrons !
means you don't need heavy shield against Neutron

Actually LESS neutrons and you'd still need a shield.