conducted successful test flights of a hydrogen-powered unmanned
aircraft believed to be the largest to fly on a proton exchange
membrane (PEM) fuel cell using compressed hydrogen. Fuel cells
have more fuel efficiency potential than regular engines and less
Fuel cells, which create an electrical current when they convert
hydrogen and oxygen into water, are attractive as energy sources
because of their high energy density. Higher energy density translates
into longer endurance.
Though fuel cells don't produce enough power for the propulsion
systems of commercial passenger aircraft, they could power smaller,
slower vehicles like unmanned aerial vehicles (UAVs) and provide a low
cost alternative to satellites. Such UAVs could also track hurricanes,
patrol borders and conduct general reconnaissance.
Fuel cell powered UAVs have several advantages over conventional UAV.
Fuel cells emit no pollution and unlike conventional UAVs, don't
require separate generators to produce electricity for operating
electronic components. "Another plus, because fuel cells operate at
near ambient temperatures, UAVs emit less of a heat signature and
would be stealthier than conventionally powered UAVs," Tom Bradley
During the next few months, the team will continue to test and refine
the aircraft, making it more reliable and robust. Ultimately, they
plan to design and build an UAV capable of a trans-Atlantic flight –
something that Parekh believes will be possible within the next five