NASA's Interstellar Boundary Explorer or IBEX spacecraft are being attached to Orbital Sciences aircraft for launch.

NASA’s Interstellar Boundary Explorer, or IBEX, spacecraft and mated Pegasus XL rocket are being attached to Orbital Sciences’ L-1011 aircraft for launch. 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