At Vandenberg Air Force Base in California, workers maneuver the Demonstration of Autonomous Rendezvous Technology (DART) spacecraft and mated upper stage toward the second stage at right in preparation or launch aboard the Orbital Sciences Pegasus XL launch vehicle. Pegasus will launch DART into a circular polar orbit of approximately 475 miles. Built for NASA by Orbital Sciences Corporation, DART was designed as an advanced flight demonstrator to locate and maneuver near an orbiting satellite. DART weighs about 800 pounds and is nearly 6 feet long and 3 feet in diameter. DART is designed to demonstrate technologies required for a spacecraft to locate and rendezvous, or maneuver close to, other craft in space. Results from the DART mission will aid in the development of NASA’s Crew Exploration Vehicle and will also assist in vehicle development for crew transfer and crew rescue capability to and from the International Space Station.