OTD…April 12 and STS-1 and 51D

#OTD in 1988…Discovery returned Americans to space after the Challenger accident

OTD in 1994…Endeavour experienced an on-pad abort due to a main engine problem during startup

Studying the atmosphere as part of NASA’s Mission to Planet Earth was the objective of shuttle Atlantis’ STS-45 mission in March 1992.