December 15th - on this day in 1960, the third and final Atlas-D Able rocket was used to launch NASA's Pioneer P-31 lunar orbiter. The rocket took to the skies from Cape Canaveral's Launch Complex 12. However, like the two earlier Atlas-D Able missions (the first of which was actually was lost during a pre-launch static fire test), the flight ended in a spectacular failure, when vibration or debris from the Able adapter section ruptured the liquid oxygen tank of Atlas, causing the vessel to expl

On this day in history, Alan Shepard launched aboard a Mercury capsule to become the first American in space. This 15-minute suborbital journey in 1961 led to big plans for human spaceflight, including the goal to send humans to the Moon. https://go.nasa.gov/3eiRcCO | NASA's Johnson Space Center

#OTD in 1961, Naval aviator Alan Shepard became the first American to travel into space. Graduating from the U.S. Naval Academy in 1944, Shepard became one of the Mercury Seven astronauts in 1959. He would walk on the moon in 1971 as commander of Apollo 14. #NationalAstronautDay | U.S. Naval Institute