The radioisotope thermoelectric generator RTG in the foreground has been removed from its caged enclosure.

On Complex 41 at Cape Canaveral Air Force Station in Florida, the radioisotope thermoelectric generator (RTG) in the foreground has been removed from its caged enclosure. The RTG will be installed on the New Horizons spacecraft encapsulated inside the fairing, at right. Designed and integrated at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., New Horizons will launch on a nine-and-a-half-year voyage to Pluto. Typical of RTG-based systems, as on past outer-planet missions, New Horizons does not have a battery for storing power. At the start of the mission, the RTG, which provides power through the natural radioactive decay of plutonium dioxide fuel, will supply approximately 240 watts (at 30 volts of direct current) - the spacecraft’s shunt regulator unit maintains a steady input from the RTG and dissipates power the spacecraft cannot use at a given time. By July 2015 (the earliest Pluto encounter date) that supply decreases to 200 watts at the same voltage, so New Horizons will ease the strain on its limited power source by cycling science instruments during planetary encounters. On Complex 41 at Cape Canaveral Air Force Station in Florida, workers on the ground oversee the radioisotope thermoelectric generator (RTG) being lifted into the Vertical Integration Facility. The RTG will be installed on the New Horizons spacecraft within the fairing at the top of the Atlas V launch vehicle. Designed and integrated at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., New Horizons will launch on a nine-and-a-half-year voyage to Pluto. Typical of RTG-based systems, as on past outer-planet missions, New Horizons does not have a battery for storing power. At the start of the mission, the RTG, which provides power through the natural radioactive decay of plutonium dioxide fuel, will supply approximately 240 watts (at 30 volts of direct current) - the spacecraft’s shunt regulato