OTD…April 29 and STS-51B

#OTD in 1992…Discovery launched with the first International Microgravity Laboratory.

#OTD in 2007…Discovery launched Harmony as the gateway to future international science laboratories

America’s first space shuttle launched on this day 35 years ago as the reusable flying machine, Columbia, lifted off from Kennedy Space Center with John Young and Bob Crippen aboard.