OTD…April 4 launches of STS-6 and 83

#OTD in 1990…Columbia launched to retrieve NASA’s Long duration Exposure Facility (LDEF) on the longest Shuttle flight to date.

Today in 2011, shuttle Discovery made a graceful landing at Kennedy Space Center, returning from her final voyage after a remarkable three-decade life of service.

#OTD in 1995, Endeavour launched on the ASTRO-2 astronomy mission: