Thorium vehicle will run 100 years on 8 grams of fuel

[johnd83]

4. Those are different technologies

Those technologies are called "radioisotope thermal generators". They work off the natural decay of the material. Atoms like plutonium and uranium naturally decay over time and release heat and radiation. This decay is normally slow and doesn't generate much energy. These RTG devices probably wouldn't power a coffee pot because they are so low power. The more recent missions including the Curiosity rover use a standardized RTG:

http://en.wikipedia.org/wiki/Multi-Mission_Radioisotope_Thermoelectric_Generator

A spaced-based plutonium nuclear reactor was supposed to be developed in the mid-2000s for use on the Jupiter Icy Moons Orbiter but was killed by the Bush administration.

http://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Orbiter

The Russians however launched a plutonium based space reactor in the 80s (I think it was the 80s, don't quote me on that). Thorium has many more moving parts compared to a plutonium reactor so isn't really well suited for space where nuclear waste management isn't really as big an issue. There is so much natural radiation outside the magnetic shield of the Earth the extra radiation from a small reactor is negligible.