US DEPARTMENT OF ENERGY / SCIENCE PHOTO LIBRARY US DEPARTMENT OF ENERGY / SCIENCE PHOTO LIBRARY
Artist's impression of a probe exploring the rings of Saturn. The probe is powered by the SP-100 nuclear reactor, the core of which is only 0.03 cubic metres in size. SP-100 was originally designed under the US Strategic Defense Initiative (SDI, or 'Star Wars') programme. It is a 100 kW reactor, which uses liquid sodium as its coolant. The sodium is heated by the reactor, then pumped through a thermoelectric generator. Excess heat is disposed of through radiators. SP-100 will be of use in distant solar system exploration, as the light from the sun at such distances is too weak to power solar cells.
Model release not required. Property release not required.