KENNEDY SPACE CENTER, FLA. - The Demonstration of Autonomous Rendezvous Technology (DART) spacecraft and Orbital Sciences Pegasus launch vehicle, mated earlier, arrive at the Vandenberg Air Force Base runway for mating to the belly of the Stargazer L-1011 aircraft (foreground). The Pegasus XL will launch DART at approximately 40,000 feet above the Pacific Ocean into a circular polar orbit of approximately 475 miles. DART was designed and built for NASA by Orbital Sciences as an advanced flight demonstrator to locate and maneuver near an orbiting satellite. The DART spacecraft weighs about 800 pounds and is nearly 6 feet long and 3 feet in diameter. The DART satellite provides a key step in establishing autonomous rendezvous capabilities for the U.S. Space Program. While previous rendezvous and docking efforts have been piloted by astronauts, the unmanned DART satellite will have computers and cameras to perform its rendezvous functions.