VANDENBERG AIR FORCE BASE, Calif. - At Vandenberg Air Force Base in California, the NASA's Interstellar Boundary Explorer, or IBEX, spacecraft seen here is being prepared for a spin balance test. The IBEX satellite will make the first map of the boundary between the Solar System and interstellar space. IBEX is the first mission designed to detect the edge of the Solar System. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the Solar System and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the Solar System that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. IBEX is targeted for launch from a Pegasus XL rocket on Oct. 5. Photo credit: NASA/VAFB KSC-08pd2506
