On March 10, 1972, an Atlas-Centaur rocket blasted off from pad LC-36A at Cape Canaveral, Florida, carrying the unmanned probe Pioneer 10 on humanity’s first mission to the planet Jupiter. This was the Pioneer Plaque, a message to the stars on behalf of all mankind – our first attempt to communicate with extraterrestrial beings. Then, with the addition of the outline of the spacecraft for scale, the Pioneer Plaque was at last complete. When the Pioneer Plaque was revealed to the American public, it ignited a storm of controversy. Yet despite this backlash, NASA was impressed by Sagan’s work on the Pioneer Plaque, and in 1977 they invited him to create another cosmic message to place aboard the Voyager 1 and Voyager 2 planetary probes.