Skylab, the first American space station, headed for orbit 50 years ago, on May 14, 1973. It was designed to accommodate three astronauts at a time for up to 56 days per mission. The astronauts would study Earth, the Sun, and how their own bodies adapted to a long period of weightlessness. During launch, however, a protective shield broke away, tearing off one of Skylab's solar panels and jamming another shut. Without the missing shield, interior temperatures climbed to 130 degrees Fahrenheit. NASA had to delay the launch of the first astronaut crew while it devised a way to save the damaged space station. [NASA]