The concern with unmanned aerial vehicles, otherwise known as drones, has always been their capacity for covert surveillance and remote killing. However, like other types of aircraft, the length of time they could spend in the air was limited to their fuel capacity. Technological advances by researchers at the Department of Defense could soon eliminate that limitation and make drones an even bigger concern:
Researchers at the U.S. Naval Research Laboratory say they’ve set a record by flying a liquid-hydrogen powered unmanned aerial vehicle for 48 hours straight.
The flight breaks the previous record of 26 hours set by the same Ion Tiger electric fuel cell drone when it was powered with gaseous hydrogen stored at 5,000 psi, they said.
The cryogenic liquid hydrogen was stored in a lightweight tank, allowing more hydrogen to be carried on board to increase flight endurance, NRL scientist Karen Swider-Lyons said.