The benefits are obvious.
Because a Nuclear Thermal Rocket (NTR) releases ten million times the energy of reactions in a chemical rocket, nuclear-powered rockets could cut current interplanetary transit times by half or better.
NASA is collaborating with the Department of Energy on the research with a goal of fabricating nuclear fuel elements by 2014.
click pic for more on nuclear powered ship
This would make Jupiter reachable in two and a half years instead of six; Mars in three months instead of eight. And with layovers and customs, it would almost be quicker for astronauts to get to the moon than to fly commercial from Miami to Kathmandu.