OTD…Aug. 27 and STS-51I

#OTD in 2000…Discovery launched on the 100th space shuttle mission

American and Soviet crews were launched today in 1975 for the first handshakes in space between the two superpowers as part of the Apollo-Soyuz Test Project.

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.