Associate Administrator for Space Operations Bill Gerstenmaier and Charlie Bolden monitor the countdown to launch of space shuttle Discovery.

In Firing Room 4 of the Launch Control Center at NASA's Kennedy Space Center in Florida, Associate Administrator for Space Operations Bill Gerstenmaier and NASA Administrator Charlie Bolden monitor the countdown to launch of space shuttle Discovery on its STS-133 mission to the International Space Station.

Discovery and its six-member crew are on a mission to 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 making 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/Kim Shiflett