At a Pegasus booster processing facility at Vandenberg Air Force Base in California technicians prepare.

At a Pegasus booster processing facility at Vandenberg Air Force Base in California, technicians prepare a section of the aft skirt for installation on the Pegasus XL rocket's (seen to the left) first stage.

The Orbital Sciences Corp. Pegasus rocket will launch the Nuclear Spectroscopic Telescope Array (NuSTAR) into space. After the rocket and spacecraft are processed at Vandenberg, they will be flown on the Orbital Sciences’ L-1011 carrier aircraft to the Ronald Reagan Ballistic Missile Defense Test Site at the Pacific Ocean’s Kwajalein Atoll for launch. The high-energy x-ray telescope will conduct a census for black holes, map radioactive material in young supernovae remnants, and study the origins of cosmic rays and the extreme physics around collapsed stars. For more information, visit science.nasa.gov/missions/nustar/. Photo credit: NASA/Randy Beaudoin, VAFB