Inside a Pegasus booster processing facility at Vandenberg Air Force Base in California, all three fins on the aft end of the Orbital Sciences Corp. Pegasus XL rocket's first stage have been installed. The Pegasus will launch the NuSTAR) spacecraft from the Ronald Reagan Ballistic Missile Defense Test Site at the Pacific Ocean’s Kwajalein Atoll. Image credit: NASA/Randy Beaudoin, VAFB Nov. 21, 2011