This is not the same. It's nuclear electric propulsion, not nuclear thermal propulsion. A nuclear reactor generates electricity and that electricity drives an i

This is not the same. It's nuclear electric propulsion, not nuclear thermal propulsion. A nuclear reactor generates electricity and that electricity drives an ion thruster. The specific impulse is astounding (7000 seconds vs 450 seconds for the best chemical rockets), but the thrust is absolutely wimpy (15 Newtons, vs 250 kilo-Newtons for the US NERVA nuclear thermal rocket engine).