Stock Photo - Space shuttle Discovery's main gear touches down on Runway 15 at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. Landing was at 11:57 a.m. (EST) on March 9, 2011, completing a more than 12-day STS-133 mission to the International Space Station. Onboard are NASA astronauts Steve Lindsey, commander; Eric Boe, pilot; Steve Bowen, Alvin Drew, Michael Barratt and Nicole Stott, all mission specialists. Discovery and its six-member crew 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.