NRL’s Ion Tiger Breaks Its Own Electric UAV Flight Record

By Brett Davis



Researchers at the U.S. Naval Research Laboratory broke their own flight time record with their fuel-cell powered Ion Tiger unmanned aircraft, clocking in 48 hours and one minute in mid-April.



The feat bests their previous 26-hour, two-minute flight in 2009. In that flight, the Ion Tiger was fueled by gaseous hydrogen; in the new record flight, it used liquid hydrogen stored in a new, NRL-developed cryogenic tank and delivery system.



Liquid hydrogen is three times denser than compressed hydrogen, allowing more fuel to be carried on board, thereby increasing flight time.



“Liquid hydrogen coupled with fuel-cell technology has the potential to expand the utility of small unmanned systems by greatly increasing endurance while still affording all the benefits of electric propulsion,” says Dr. Karen Swider-Lyons, NRL principal investigator.



The design bridges the gap between long-endurance, but noisier, hydrocarbon-fueled systems and quieter, but shorter-range, electrical UAS, NRL says.



Supplying liquid or gaseous hydrogen could be tricky in battle zones, but NRL is proposed to manufacture it on site by using an electrolyzer-based system, possibly powered by solar or wind power, to create it.