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.
Related Articles
OTD…June 18 and STS-7 and LRO
June 18, 2015
Mars rover re-routed after spinning wheels on steep hillside
April 1, 2016
OTD…July 23 and STS-93
July 23, 2015