ISS039-E-014705 (22 April 2014) --- Expedition 39 Commander Koichi Wakata of the Japan Aerospace Exploration Agency (JAXA) inputs data in a computer in JAXA's Kibo laboratory on the International Space Station. On this day, two flight engineers -- NASA astronauts Steve Swanson and Rick Mastracchio -- went outside the orbital outpost to replace a failed backup computer relay box in the S0 truss.