A picture of the Ion Tiger in flight and a 550 W fuel cell
The Ion Tiger in flight and a 550 W fuel cell (insert)

The Ion Tiger program demonstrates a practical, lightweight fuel cell system for unmanned airvehicles (UAVs) to significantly improve battlefield surveillance and communications capabilities.

Ion Tiger’s electric fuel cell propulsion system has the low noise and low signature of a battery-powered UAV, while taking advantage of hydrogen, a high-energy fuel. The 550-W (0.75-horsepower) fuel cell has about four times the efficiency of a comparable internal combustion engine. The Ion Tiger flew for 26 hours in November 2009 while carrying a 5-pound payload using hydrogen compressed to 5000-psi in a carbon/aluminum pressure vessel. In May 2013, the same researchers at the U.S. Naval Research Laboratory flew their fuel cell powered Ion Tiger UAV for 48-hours and 1 minute on April 16-18 by using liquid hydrogen fuel in a new, NRL-developed, cryogenic fuel storage tank and delivery system. These 1-day and 2-day demonstrations prove that hydrogen fuel cells provides a clear path to long endurance electric flight: in comparison, the Ion Tiger would be able to fly for only 4 hours on the comparable amount of lithium batteries.

The Naval Research Laboratory's research on fuel cell systems and UAVs converge successfully in the Ion Tiger to enable long-endurance missions, allowing a large cruise range and reducing the number of daily launches and landings. The electric power system has the additional features of instant starting, near-silent operation, and low thermal signature. Fuel cell technologies can deliver energy savings and increased capabilities across the operational spectrum, to ground, air, and undersea vehicles and for man-portable power generation.

Principal Investigator:
K. Swider-Lyons
Chemistry Division
Naval Research Laboratory
Washington DC 20375

Publication Approval: 

Key publications

K. E. Swider-Lyons, Stroman, R. O. , Rodgers, J. A. , Edwards, D. , MacKrell, J. A. , Schuette, M. W. , and Page, G. S. , Liquid hydrogen fuel system for small unmanned air vehicles, in Proceedings of 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013, Grapevine, TX, 2013.
K. E. Swider-Lyons, MacKrell, J. A. , Rodgers, J. A. , Page, G. S. , Schuette, M. W. , and Stroman, R. O. , Hydrogen Fuel Cell Propulsion for Long Endurance Small UAVs, in Proceedings of the Naval Centennial of Flight Forum, 2011.