Skylab, America's first space station, launched on May 14, 1973. Within sixty seconds, things went badly wrong. A protective heat shield tore off during launch, ripping away one of the station's two solar panels and jamming the other one shut. Without solar panels, Skylab had almost no electricity. Without the heat shield, the Sun heated the station's interior to over 126 degrees Fahrenheit. NASA had a problem. The station was in orbit, but it was too hot and too dark to live in. Engineers on the ground worked quickly to find a solution. The first crew of astronauts arrived eleven days later carrying a makeshift sunshade made of thin material similar to a space blanket. They pushed the sunshade through an airlock and unfolded it over the damaged area. The temperature dropped. Then they performed a spacewalk to free the jammed solar panel. It snapped open, and power flowed. Over the next year, three crews lived aboard Skylab. They spent a total of 171 days in space, conducting 270 experiments. They studied how the human body responds to weightlessness over weeks and months. They discovered that bones lose calcium and muscles shrink without gravity, findings that helped NASA plan for longer missions to come. Skylab proved that people could live and work in space for extended periods.