The Perseus B remotely piloted aircraft taxis on the runway at Edwards Air Force Base, California, before a series of development flights at NASA's Dryden flight Research Center. The Perseus B is the latest of three versions of the Perseus design developed by Aurora Flight Sciences under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

A long, slender wing and a pusher propeller at the rear characterize the Perseus B remotely-piloted research aircraft, seen here during a test flight in April1998.

The Perseus proof-of-concept vehicle is seen here as it taxis on Rogers Dry Lake, adjacent the Dryden Flight Research Center, Edwards, California.

The Perseus proof-of-concept vehicle in flight at the Dryden Flight Research Center, Edwards, California in 1991. Perseus is one of several remotely-piloted aircraft designed for high-altitude, long-endurance scientific sampling missions being evaluated under the ERAST program.

The Perseus A, a remotely-piloted, high-altitude research aircraft, is seen here framed against the moon and sky during a research mission at the Dryden Flight Research Center, Edwards, California in August 1994.

The Perseus A, a remotely-piloted, high-altitude research vehicle, is seen just after landing on Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California. The Perseus A had a unique method of takeoff and landing. To make the aircraft as aerodynamic and lightweight as possible, designers gave it only two very small centerline wheels for landing. These wheels were very close to the fuselage, and therefore produced very little drag. However, since the fuselage sat so close to the ground, it was necessary to keep the large propeller at the rear of the aircraft locked in a horizontal position during takeoff. The aircraft was towed to about 700 feet in the air, where the engine was started and the aircraft began flying under its own power.

The Perseus B remotely piloted aircraft on the runway at Edwards Air Force Base, California at the conclusion of a development flight at NASA's Dryden flight Research Center. The Perseus B is the latest of three versions of the Perseus design developed by Aurora Flight Sciences under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

A long, slender wing and a pusher propeller at the rear characterize the Perseus B remotely piloted research aircraft, seen here during a test flight in June 1998.

A long, slender wing and a pusher propeller at the rear characterize the Perseus B remotely piloted research aircraft, seen here during a test flight in June 1998.

The Perseus B remotely piloted aircraft approaches the runway at Edwards Air Force Base, Calif. at the conclusion of a development flight at NASA's Dryden flight Research Center in April 1998. The Perseus B is the latest of three versions of the Perseus design developed by Aurora Flight Sciences under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

The Perseus B remotely piloted aircraft nears touchdown at Edwards Air Force Base, Calif. at the conclusion of a development flight at NASA's Dryden Flight Research Center. The Perseus B is the latest of three versions of the Perseus design developed by Aurora Flight Sciences under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

Crew members check out the Perseus proof-of-concept vehicle on Rogers Dry Lake, adjacent to the Dryden Flight Research Center, Edwards, California, after a test flight in 1991.

The Perseus proof-of-concept vehicle flies over Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, to test basic design concepts for the remotely-piloted, high-altitude vehicle.