Hyperion Power Generation's mini nuclear reactors - 1.5 by 2.5 metres in size, powerful enough to provide 20,000 homes with power for a decade

Here's an article detailing something I mentioned a few days ago, using tiny nuclear reactors as a kind of battery to power missions of just about any kind in space. The page for the company that makes them can be seen here and they advertise them not just for usage in space but anywhere else as well - the cost is $50 million for a single one of these devices.

A nuclear battery of this kind is only useful for unmanned exploration at the moment, since all of the potential manned destinations we are looking at are ripe with solar energy. Even the Moon's 14-day night is irrelevant right now since the only area we will be colonizing in the beginning will be the nearly permanently lit areas at the south pole. But for a long-term mission to a moon like Europa, Enceladus or Titan, or the outer planets Ouranos (Uranus) or Neptune something like this would be necessary.

Scheduled release date for these mini reactors: 2013.