S77-28139 (13 Sept 1977) --- The Orbiter 101 "Enterprise" is seen riding "piggy-back" atope the NASA 747 carrier aircraft during the second free flight of the Shuttle Approach and Landing Tests (ALT) conducted on September 13, 1977, at the Dryden Flight Research Center in Southern California. Moments later the Orbiter 101 separated from the 747 and made a five-minute, 28-second unpowered flight before landing. Astronauts Joe H. Engle, commander, and Richard H. Truly, pilot, were the crew of the "Enterprise." two T-38 chase planes are seen in the background. The ALT free flights are designed to verify orbiter subsonic airworthiness, integrated systems operations and pilot-guided approach andlanding capability and satisfy prerequisites to automatic flight control and navigation mode. Astronaut Vance D. Brand took this picture while riding in T-38 chase plane number five. He used a 70mm Hasselblad camera with an 80mm lens.