OTD…Oct. 15 and Cassini

#OTD in 1994…Discovery launched to develop new techniques for monitoring Earth’s environment from space…and in 2006…Construction of the space station resumed as Atlantis delivered a power-generating truss

#OTD in 1998…The launch of Discovery on final shuttle-Mir docking mission

#OTD in 1983…Challenger lifts off on the first nighttime shuttle launch…and Discovery launches on her inaugural Spaceflight