NAVAL RESEARCH LABORATORY
Ion Tiger made its first flight in 2009 using gaseous hydrogen as fuel. The fuel was compressed to 5,000 pounds per
square inch, and stored in a tank about the size of a pumpkin. The UAV is shown here during a November 2009 test
flight in which it remained airborne for more than 26 hours.
within the motors leads to significant voltage losses over
time, hindering performance.
Eventually, as solutions are found and the price tag
comes down, Swider-Lyons believes hydrogen fuel
cells may become the most cost-effective means of aircraft propulsion.
“For the military, if you can decrease the number of airplanes launched and landed, there’s a big cost [saving].
And it’s a huge expense when you lose a bird,” she said.
In time, Swider-Lyons and MacKrell said, the job of
developing and implementing a system robust enough
to use in combat lies with industry.
Companies such as Boeing and AeroVironment have
been working on developing proprietary hydrogen fuel
cell-powered aircraft. Boeing announced the successful
test flights of a manned aircraft in 2008, and the company’s
unmanned Phantom Eye high-altitude aircraft in June
2012. AeroVironment’s Global Observer high-altitude
unmanned aircraft flew for about five hours over Edwards
Air Force Base, Calif., during a 2011 test mission.
The armed forces, Swider-Lyons said, continue to move
toward an infrastructure that includes cryogenic hydrogen
in its inventory, even amid an institutional Defense
Department preference toward conventional JP- 8 jet fuel.
One possible scenario for low-level hydrogen fuel cell
aircraft could involve a hub-and-spoke model, she said.
“You could have a standard base you’re flying airplanes
from. If you have endurance, it changes operations a lot,”
Swider-Lyons said. “You could launch one, have it hang
out for a couple of hours until it’s needed, and then re-
Marines, Sailors and Soldiers may no longer have to
carry small, unmanned aerial vehicles to the field in
backpacks, said MacKrell.