OTD…April 12 and STS-1 and 51D

#OTD in 1984…Challenger launched the Earth Radiation Budget Satellite

The first crew to inhabit Skylab — Conrad, Weitz and Kerwin — launched today in 1973 for a 28-day mission that successfully made critical repairs, brought the station into operation and conducted solar astronomy, Earth resources and medical experiments.

#OTD…The maiden launch of shuttle Endeavour in 1992 to rescue the Intelsat 603 satellite