S132-E-009058 (21 May 2010) --- Inside the Unity node, NASA astronaut Tracy Caldwell Dyson, Expedition 23 flight engineer, goes through some acrobatics that would be impossible in Earth gravity. She might be celebrating the completion of three successful space walks on the International Space Station, performed outside by three STS-132 astronauts working in pairs on three separate days, and supported inside by the other ten astronauts and cosmonauts sharing chores on the orbital outpost. Photo credit: NASA or National Aeronautics and Space Administration