UK could use plutonium in space nuclear power demonstration

http://www.flightglobal.com/articles/2010/02/15/338369/uk-could-use-plutonium-in-space-nuclear-power-demonstration.html

On Earth, nuclear power is controversial - but for deep space missions it is a necessity. However, the plutonium driving spacecraft power systems is invaluable not only for its ability to keep electricity flowing where solar cells cannot; Pu-238 is also in short supply.