OTD…Oct. 20 and STS-73

#OTD in 1992…Discovery launched with the first International Microgravity Laboratory.

#OTD in 1997…Columbia launched on the reflight of her shortened Microgravity Science Laboratory mission

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