Vulture Air Vehicle Program

The Helios Prototype was a unique electrically powered experimental lightweight flying wing developed by AeroVironment, Inc., under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. Using energy derived from the sun by day and from fuel cells at night, the Helios Prototype was designed as the forerunner of high-altitude unmanned aerial vehicles that could fly on ultra-long duration environmental science or telecommunications relay missions lasting for weeks or months without using consumable fuels or emitting airborne pollutants.

Unfortunately, the program suffered a major setback when the Helios experienced control difficulties while on a checkout flight on June 26, 2003, and the aircraft suffered some structural failures and was subsequently destroyed when it fell into the Pacific Ocean about 10 miles west of the Hawaiian island of Kauai. The experimental fuel cell system carried aboard the Helios Prototype on that flight was lost. An investigation to determine the cause(s) of the control problems that led to the loss of the craft is still in progress as of this writing.

NASA established two major goals for the Helios Prototype uninhabited aerial vehicle (UAV). The first milestone was to reach an altitude at or near 100,000 ft. on a single-day flight with a small payload. This mission was to demonstrate that an aircraft could carry a science instrument to extreme altitudes. The power required to lift a small (100 lb.) payload to 100,000 ft. also enables the aircraft to carry much larger (600 lb.) payloads to altitudes up to 70,000 ft., making the Helios platform a versatile UAV.

In diminishing sunlight on August 13, 2001, Helios effectively demonstrated this capability when it reached an unofficial record altitude for non-rocket-powered aircraft of 96,863 feet.

NASA claimed that if the concept the prototype embodied proved itself, then multi-month flight would become feasible. Accordingly, Helios was a forerunner of what some call artificial "atmospheric satellites". NASA claimed such atmospheric satellites might someday replace conventional artificial satellites.[citation needed]

The Helios Prototype is an enlarged version of the Centurion flying wing, which flew a series of test flights at Dryden in late1998. The craft has a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of its solar-powered Pathfinder flying wing, and longer than either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. It is one of several remotely-
piloted aircraft, also known as uninhabited aerial vehicles or UAV's, being developed as technology demonstrators by several small airframe manufacturers under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project.

Pathfinder is a remotely controlled, solar-powered flying wing, designed and built as a proof of concept vehicle for a much arger aircraft capable of flying at extremely high altitudes for weeks at a time.

The Defense Advanced Research Projects Agency last week awarded contracts to Manassas, Va.-based Aurora Flight Services and top defense contractors Boeing and Lockheed Martin to develop working prototypes of the Vulture, according to the aerospace news service Flight.