Ultimately, the Global observer will be powered by a liquid-hydrogen-fueled propulsion system. AeroVironment had explored the use of solar power for the aircraft , but determined that liquid hydrogen propulsion was the best solution for a high-altitude, long-endurance UAV. Solar power today is not sufficient to support continuous operation beyond the tropics during winter.
The chemical reaction that takes place between the water and the fuel pellets produces hydrogen, which moves up into the fuel cell to produce electricity.
The power produced can be used immediately.
"Global Observer is being developed to address the need for an affordable, persistent platform that can provide seamless communications and ISR over any spot on the globe for as long as required,” Curtin said.
“Swapping orbits every 5 to 7 days, a two-air vehicle system would maintain uninterrupted coverage in a manner similar
to a geosynchronous satellite, but about 2,000 times closer to the earth's surface."