Telecom Looks to Solar-Powered Planes to Reduce Overhead

Telecom Looks to Solar-Powered Planes to Reduce Overhead

Telecom researchers have successfully tested a solar-powered, remotely operated aircraft capable of relaying high-quality television, cell phone, and Internet signals and transmissions to the ground. The aircraft, called Pathfinder-Plus, is a High Altitude Platform Station (HAPS) that could offer telecom companies a less expensive alternative to satellites for broadcasting television or wireless signals.

Pathfinder-Plus was tested three times in June and July through a collaboration between its maker, AeroVironment, the Japanese Ministry of Communications, and NASA. Work is now being done by engineers at NASA and AeroVironment to extend the flight time of solar-powered aircraft in the stratosphere to more than two weeks. The ultimate goal is to allow them to fly, with a HAPS-capable telecommunications payload, for more than six months.

During its first demonstration, the Pathfinder-Plus climbed 65,600 feet into the Earth’s stratosphere, where it orbited the U.S. Navy’s Pacific Missile Range Facility for two hours, retransmitting high-quality television signals sent by telecom researchers from the Japanese Ministry of Communication. The signals were picked up by HDTV monitors on the ground and were broadcast using only one watt of power. The signal covered an area equivalent to a large metropolitan area and surpassed traditional TV broadcasts in terms of quality.

“Its absolutely amazing what the right vantage point can deliver,” said John Del Frate, project manager for solar powered aircraft at NASA’s Dryden Flight Research Center. “It was better than any HDTV system I have ever seen in the United States -- virtually photographic quality. It was very impressive.”

Pathfinder-Plus’s second demonstration established a third-generation mobile phone wireless link at 65,600 feet. After establishing a link, the Japanese team was able to relay cell phone calls and video conferencing through the solar-powered plane for more than four hours. As it descended to 24,000, the team also established an Internet link through the plane.

The third flight, which occurred this month, saw the Pathfinder-Plus carry a third-generation IMT-2000 mobile telecommunications system capable of voice, data, and video two-way cell phone transmissions. Engineers also used a new “look down” antenna that helped eliminate problems with interference from other signals experienced during the second flight.