Nimbus 3
NASA launches the Nimbus 3 satellite, designed to observe weather patterns from orbit and test new weather and climate detection technologies. Nimbus 3 is the first Earth-orbiting spacecraft to test the SNAP-19 radioisotope thermoelectric generator system; devices similar to the SNAP-19 will become the primary power source for later deep space and outer solar system interplanetary missions. Nimbus 3 loses attitude control in 1970, but is kept online for engineering information-gathering purposes until 1972.