Space Shuttle Columbia (STS-50) launches from Cape Kennedy Space Center. Credit: NASA
On June 25, 1992 the space shuttle Columbia launched from Kennedy Space Center on its 12th mission (STS-50) carrying a crew of 7 astronauts and scientists. It’s primary payload consisted of the United States first Microgravity Laboratory-I (USML-1), a manned spacelab module designed to advance U.S. microgravity research efforts. The 13 day mission was also the first to use the Extended Duration Orbiter (EDO) which included equipment and fuel for extra energy production, additional nitrogen tanks for cabin air, and a regeneration system to remove carbon dioxide. These additional systems allowed STS-50 to become the longest space shuttle mission to date lasting 13 days, 19 hours, and 30 minutes.
Top: Crew Members of STS-50. Bottom: Microgravity Lab (USML-1.) Credit: NASA
Working around-the-clock in two 12-hour shifts, the astronauts oversaw 31 experiments in crystal growth, combustion science, fluid physics and biotechnology aboard the 23-foot-long pressurized spacelab module in the shuttle’s payload bay. Previous microgravity experiments were limited to the amount of time a shuttle could remain in orbit. Space shuttle mission STS-32 provided eleven days of microgravity. Thanks to the EDO, the space shuttle Columbia mission STS-50 remained in orbit for 48 hours longer than STS-32. The EDO was integral in extending flight time of future shuttle missions which could now potentially last as long as a month.
STS-50 Microgravity Lab module in cargo bay of Space Shuttle Columbia. Credit: NASA
The goal of the EDO was also to examine the astronauts’ physical and psychological performance in close quarters over the span of a long mission. During STS-50, crew members conducted biological tests as part of the EDO Medical Project. Crew members monitored their blood pressure and heart rate and took samples of the cabin atmosphere during the flight. They also evaluated a Lower Body Negative Pressure (LBNP) device as a countermeasure to the normal reduction of body fluids that takes place in space, which affects astronauts upon returning to Earth. The EDO provided new information on the effects of long term human stay in space and would prove integral in developing future NASA projects like the International Space Station.