The Proteus high-altitude aircraft on the ramp at the Mojave Airport in Mojave, California.

The uniquely shaped Proteus high-altitude aircraft soars over California’s Mojave Desert during a July 1999 flight.

The uniquely-shaped Proteus high-altitude research aircraft lifts off from the runway at the Mojave Airport in Mojave, California.

The unusual design of the Proteus high-altitude aircraft, incorporating a gull-wing shape for its main wing and a long, slender forward canard, is clearly visible in this view of the aircraft in flight over the Mojave Desert in California.

The unusual design of the Proteus high-altitude aircraft, incorporating a gull-wing shape for its main wing and a long, slender forward canard, is clearly visible in this view of the aircraft in flight over the Mojave Desert in California.

A frontal view of the Proteus high-altitude aircraft on the ramp at the Mojave Airport in Mojave, California in July 1999.