OTD…April 19 and STS-100

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

#OTD in 1995…Endeavour launched to deploy and retrieve solar satellite and Wake Shield Facility

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.