OTD…Sept. 21 and Endeavour retirement

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

#OTD in 1982…Columbia launches on the fourth space shuttle mission. #OTD in 1995…Atlantis launches on first shuttle-Mir docking flight

#OTD in 1992…Columbia launches on the first Extended Duration Orbiter mission