An Orbital Sciences technician completes final checks of NASA's Nuclear Spectroscopic Telescope Array inside the Orbital Sciences processing facility.

An Orbital Sciences technician completes final checks of NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, inside the Orbital Sciences processing facility at Vandenberg Air Force Base in California before the Pegasus payload fairing is secured around it. NuSTAR already is mated to its Pegasus XL rocket, which is positioned behind the spacecraft outside the environmental enclosure. Encapsulation of NuSTAR in its fairing is a significant prelaunch milestone.

The fairing will protect the spacecraft from the heat and aerodynamic pressure generated during ascent to orbit. After processing of the rocket and spacecraft are complete, they will be flown on Orbital's L-1011 carrier aircraft from Vandenberg to the Ronald Reagan Ballistic Missile Defense Test Site on the Pacific Ocean’s Kwajalein Atoll for launch in March. The high-energy x-ray telescope will conduct a census of 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 http://www.nasa.gov/nustar. Photo credit: NASA/Randy Beaudoin, VAFB