The Reduced Gravity Walking Simulator was a facility developed by NASA in the early 1960s to study human movement under simulated lunar gravity conditions. It was located at NASA's Langley Research Center in Virginia and was designed to prepare astronauts for the Moon landings during the Apollo program. The simulator was tilted at a 9.5-degree angle from the vertical and test subjects were suspended on their side by cables at the same angle. This set-up allowed the trainees to walk along the surface while experiencing only one-sixth of Earth's gravity. It was also used to study the physiological effects on the astronaut's body during movement. In total, 24 astronauts used the simulator to train for lunar missions, including all three astronauts of the Apollo 1 mission. This photograph, taken in 1963, shows a test subject being suited up by two technicians on the Reduced Gravity Walking Simulator.
