Bigger than the blimp

Researchers from

are working to develop a high-altitude, helium-filled craft that may hover over the same spot for up to a year. About 10 Purdue researchers are involved in the work, funded by the US Air Force Research Laboratory.

‘The concept is to have an airship that flies above 65,000 feet and is geostationary, which means it stays in the same position over the Earth,’ said Oleg Wasynczuk, a professor of electrical and computer engineering at Purdue who is leading the project with John Sullivan, a professor of aeronautics and astronautics.

Engineers are not yet certain how large the airship might be, but it may be as long as 300 metres, or around 900 feet - roughly four times the length of the Goodyear blimp. The airship will be powered by solar cells and an advanced fuel cell, and a customised control system will help keep it steady in high winds.

Because the unmanned ship might have to remain in flight for as long as a year at a time, it will be equipped with innovative power systems to provide electricity. The researchers plan to cover a portion of its skin with photovoltaic cells, which will provide electricity during the day to power the ship and also run equipment that turns water into hydrogen and oxygen. During the night, the hydrogen and oxygen would then be used to run a ‘regenerative fuel cell’, said Revankar. As the fuel cell generated electricity, it would produce water, which would be returned to the system to begin the cycle over again during daytime hours.