STS133-S-147 (9 March 2011) --- Employees gather underneath space shuttle Discovery on the Shuttle Landing Facility's Runway 15 at NASA's Kennedy Space Center in Florida. In the foreground, NASA Administrator Charlie Bolden congratulates astronaut Steve Lindsey, STS-133 commander, on a successful mission. Lindsey and his crew returned from a 13-day, 5.3-million-mile mission to the International Space Station at 11:57 a.m. (EST) on March 9, 2011. STS-133 delivered the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, the dexterous humanoid astronaut helper, to the orbiting outpost. STS-133 was Discovery's 39th and final mission. This was the 133rd Space Shuttle Program mission and the 35th shuttle voyage to the space station. Photo credit: NASA or National Aeronautics and Space Administration