NASA Fires Up Powerful Lithium-Fed Thruster for Trips to Mars

[OKIsItJustMe]

8. NERVA was not the same as Orion

Orion was a proposal to use a series of nuclear explosions to power a spacecraft (a silly/insane idea IMHO, but one which keeps coming back!)

NERVA simply used a nuclear reactor as a heat source, instead of burning the fuel to provide the heat to expand the gases for propulsion. I don’t believe it would have been able to lift a spacecraft into orbit, however, it was considered for use on the upper stage(s) of the Saturn V.