OTD…July 31 and STS-46

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

#OTD in 1997…Cassini was launched on its billion-mile trek to Saturn

NASA’s Kepler planet-finder began its mission to discover Earth-like worlds orbiting other stars in the galaxy today in 2009, successfully launching aboard a Delta 2 rocket from Cape Canaveral.