OTD…Aug. 28 and STS-128

#OTD in 2009…Endeavour launched to complete the Japanese segment of the International Space Station

#OTD in 1991, 1992 and 1993…flights by Discovery and Endeavour

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.