Helios Prototype

The Helios Prototype is a remotely piloted flying wing aircraft developed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. The two primary goals of the Helios Prototype development are to demonstrate sustained flight at an altitude near 100,000 feet and flying non-stop for at least 24 hours, including at least 14 hours above 50,000 feet.

NASA Fact Sheet