The Orbital Sciences L-1011 aircraft is being prepared to receive the Pegasus XL rocket and NASA's Interstellar Boundary Explorer or IBEX spacecraft.

On the ramp on Vandenberg Air Force Base in California, the Orbital Sciences’ L-1011 aircraft is being prepared to receive the Pegasus XL rocket and NASA’s Interstellar Boundary Explorer, or IBEX, spacecraft. IBEX is targeted for launch from the Kwajalein Atoll, a part of the Marshall Islands in the Pacific Ocean, on Oct. 19. IBEX will be launched aboard the Pegasus rocket dropped from under the wing of the L-1011 aircraft flying over the Pacific Ocean. The Pegasus will carry the spacecraft approximately 130 miles above Earth and place it in orbit. The IBEX satellite will make the first map of the boundary between the Solar System and interstellar space. Photo credit: NASA/Mark Mackley, VAFB