Jet Propulsion Laboratory (JPL) worker Mary Reaves mates connectors on a radioisotope thermoelectric generator (RTG) to power up the Cassini spacecraft, while quality assurance engineer Peter Sorci looks on. The three RTGs which will be used on Cassini are undergoing mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by JPL KSC-97PC1092