How is the spacecraft powered?
Galileo uses two Radioisotope Thermoelectric Generators (or RTGs for short) to generate electrical power. The RTGs power the spacecraft through the radioactive decay of Plutonium-238. The decay emits heat, which is converted into electricity for the spacecraft to “see, sense, hear, and speak.” Each RTG is mounted on a 5 meter long boom. The spacecraft was able to generate 570 watts of electric power at launch; we expect that it will be able to produce 480 watts when the spacecraft actually arrives at Jupiter in December of 1995.
