This pair of shoes were designed to provide astronauts working on the Skylab Orbital Workshop with the ability to "lock" their feet in place and "stand still" while in a weightless environment.The triangular cleat on the sole of each shoe locked into the triangular grid pattern of the Skylab floor to anchor the astronaut in position. Skylab astronauts lived aboard the space station on long-duration missions of 28, 59, and 84 days in 1973-1974.These shoes were issued to astronaut Joe Kerwin, however were not flown on any Skylab mission. They were transferred to the National Air and Space Museum in 1976.