CAPE CANAVERAL, Fla. -- Space shuttle Discovery soars toward orbit atop twin columns of fire, embarking on its final flight. Launch to the International Space Station on the STS-133 mission was at 4:53 p.m. EST. Discovery and its six-member crew will deliver 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. Discovery is flying on its 39th mission and is scheduled to be retired following STS-133. This is the 133rd Space Shuttle Program mission and the 35th shuttle voyage to the space station. For more information on the STS-133 mission, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Rusty Backer and Michael Gayle