NASA pumps $400m into nuclear space probe The Register

NASA has awarded Northrop Grumman a $400m contract to co-design the Jupiter Icy Moons Orbiter (JIMO) space probe – slated for a rendevouz with Jovian moons Callisto, Europa and Ganymede some time after 2012. The JIMO project has generated a certain amount of controversy due to its uranium-fuelled nuclear fission reactor – which creates electricity to drive the “nuclear electric propulsion (NEP)” system. In simple terms, NEP uses the electricity produced by the reactor to ionise propellant atoms which can then be ejected at high velocity from the vehicle’s propulsion system by magnetic or electrified grids. NASA has already proven this “ion drive” technology aboard Deep Space 1, although electricity for the thrusters was in that case provided by solar panels.