Technicians prepare to do a fillet and wing fit check on the Pegasus XL launch vehicle.

In a clean room at Vandenberg Air Force Base in California, technicians prepare to do a fillet and wing fit check on the Pegasus XL launch vehicle. 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