Astronauts Story Musgrave, left, and Don Peterson, right, float in the cargo bay of the Earth-orbiting space shuttle Challenger during their historic April 7, 1983, spacewalk on the STS-6 mission, the Challenger's first. They are restricted via tethers to safety slide wires. Challenger launched on April 4, 1983. It launched and landed nine times before ending in tragedy on Jan. 28, 1986. Just 73 seconds into mission STS-51L, a booster failure caused an explosion that resulted in the loss of seven astronauts, as well as the vehicle.