Russian Roscosmos Nuclear Engine for Spacecraft

Russia will finish by 2018 a nuclear engine to manned spaceship for long range space exploration like Mars. Initially the basic concept was to generate thrust from the blast of external nuclear explosions that would push a damped bottom plate of the spacecraft. But newer designs plan to employ the Inertial Confinement Fusion technology.

More: http://en.wikipedia.org/wiki/Nuclear_pulse_propulsion