OTD…Oct. 5 and STS-41G

#OTD in 2006…A star-spangled start to Discovery’s STS-121 mission

Today marks the 40th anniversary — July 20, 1976 — of the first U.S. robotic landing on another planet by the Viking 1 spacecraft on Mars.

Today in 1969, the launch of Apollo 9 and the first manned flight of all lunar hardware in Earth orbit.