OTD…April 4 launches of STS-6 and 83

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.

#OTD in 2007…Discovery launched Harmony as the gateway to future international science laboratories

#OTD…Launch of a 1993 environmental mission on Discovery and Atlantis’ ISS flight in 2002