The Environmental Research Aircraft and Sensor Technology program was a joint NASA/industry initiative to develop and demonstrate technologies that would lead to remotely or autonomously operated uninhabited aerial vehicles capable of carrying out long-duration Earth science and environmental missions at high altitudes.
A highlight of the program was when the solar-powered Helios Prototype flew into aviation history in August 2001, reaching an altitude of 96,863 feet during a maximum-altitude demonstration near Hawaii. It is a certified world altitude record for non-rocket powered aircraft. A second significant achievement was the development of the Predator B, which was transferred to the military for development as a reconnaissance aircraft. The Dryden Ikhana unmanned aircraft system is a civilian version of the Predator B.