We examine a space nuclear Radioisotope Thermoelectric Stirling (RTS) generator on display at the STAIF Conference. RTS generators are a new breed of space nuclear power supply that use radioactive decay to heat water, which in turn powers a free-piston Stirling Cycle engine to produce electricity.

RTS power supplies are used on a variety of satellites and space probes by NASA and a variety of commercial interests. They commonly find use in applications deep in the solar system where energy may not be present to power a solar array.

While space nuclear RTS and RTG’s are not commonly known, they are used in a number of space power applications, prompting concerns by activist groups worried about the possible dispersal of of radioactive elements should an RTS or RTG be accidentally destroyed in the earth’s atmosphere during launch.