Voyager RTGs launch (1977)
NASA launched Voyager 1 and 2, each powered by radioisotope thermoelectric generators that turn heat from decaying plutonium-238 into electricity. Solar panels are useless that far from the Sun, so the probes carried their own nuclear heat source.
Both spacecraft powered instruments through flybys of Jupiter, Saturn, and beyond.
Nearly 50 years later, their generators still feed a trickle of power in interstellar space, proving nuclear sources can outlast any battery or solar array.
Voyager showed why deep space needs nuclear power. BOHR tries to bring that capability to small, privately built satellites.
