On the ramp of Vandenberg Air Force Base in California is attached under the wing of an Orbital Sciences L-1011 aircraft.

On the ramp of Vandenberg Air Force Base in California, NASA’s Interstellar Boundary Explorer, or IBEX, spacecraft, which is mated to the Pegasus XL rocket, is attached under the wing of an Orbital Sciences’ 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 Oct. 19. The Pegasus rocket will be dropped from under the wing of the L-1011 over the Pacific Ocean to carry the spacecraft approximately 130 miles above Earth and place it in orbit. Photo credit: NASA/Randy Beaudoin, VAFB