The Space Shuttle Challenger Accident Investigation

VIDEO: By the light of a waning moon, the space shuttle Atlantis returned to Earth on July 21, dropping out of predawn darkness to close out NASA’s 135th and final shuttle voyage, a long-awaited – and long-dreaded – milestone marking the end of an era for American manned space flight. (Membership Required)

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.

On the 30th anniversary of the Challenger disaster, crew families, friends and space workers gathered Thursday to remember the 17 men and women who lost their lives on the high frontier, 14 in two space shuttle disasters and three in an Apollo-era launch pad fire 49 years ago Wednesday.