Nasa Dryden Helios

The forerunner of 21st-century solar-powered “atmospheric satellites”, the extraordinary Helios was a remotely piloted flying wing designed for sustained flight at the very edge of space. It was developed by AeroVironment and NASA’s Dryden Research Center to demonstrate sustained flight at almost 100.000 feet, and non-stop flight for at least 24 hours 14 of which had to be above 50,000 feet. Five underwing pods, one at each joint, carry a two-wheel undercarriage, the battery power system. flight control computers, and data instrumentation. For initial flight tests
in 1999, the 14 electric motors were powered by lithium battery packs. However, in 2000 this role was taken over by solar panels on the wing’s upper surface.
Helios’s only flight controls were 72 elevators for pitch control; turning was accomplished by varying the power of the motors. Take-off and landing speeds were sedate, similar to the average spied of a bicycle. Coincidenially. its
two rear wheels were those of a mountain bicycle: it had two smaller “scooter” wheels on the front.
Helios set a world record for sustained horizontal flight by a winged aircraft, reaching 96,863 feet on 13 August 2001. In the future, such aircraft could be used to flv autonomously for up to six months at at time on science and commercial missions.