OTD…April 29 and STS-51B

#OTD in 2001, Discovery launched on STS-102 to exchange crews aboard the International Space Station

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

Shuttle Endeavour launched for the 25th and final time on this date in 2011.