VANDENBERG AIR FORCE BASE, Calif. – In Hangar 1555 on Vandenberg Air Force Base in California, work is under way preparing NASA’s Interstellar Boundary Explorer, or IBEX, spacecraft and attached Pegasus XL rocket on its transporter for a trip to the runway. There, the rocket-spacecraft will be attached to the L-1011 aircraft. The IBEX satellite will make the first map of the boundary between the Solar System and interstellar space. IBEX is targeted for launch from the Kwajalein Atoll, a part of the Marshall Islands in the Pacific Ocean, on Oct. 19 aboard the Pegasus rocket dropped from under the wing of an L-1011 aircraft flying over the Pacific Ocean. The Pegasus will carry the spacecraft approximately 130 miles above Earth and place it in orbit. Photo credit: NASA/Randy Beaudoin, VAFB KSC-08pd3072