OTD…July 4 and STS-121

#OTD in 1990…Discovery launched the Ulysses probe bound for the sun

#OTD…Launch of Challenger in 1985 on a Spacelab research flight

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.