OTD…July 31 and STS-46

#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 2009…Endeavour launched to complete the Japanese segment of the International Space Station

#OTD in 2006…A star-spangled start to Discovery’s STS-121 mission