AeroVironment has teamed up with Lockheed Martin to pursue international customers for the liquid hydrogen-powered Global Observer, a high-altitude, ultra-long endurance unmanned air system (UAS).

The Global Observer agreement was announced on 6 February at the Defense Expo in New Delhi as part of a wider plan to also “potentially develop integrated solutions for the unmanned systems market”, says Paul Lemmo, Lockheed’s senior vice-president of corporate strategy and business development, in a news release.

Roy Minson, a senior vice-president and general manager at AeroVironment, describes the arrangement as focused on developing “atmospheric satellite systems built around Global Observer”.

The deal breathes new life into a Global Observer programme since a 2011 crash destroyed the first prototype, which was funded by the US military. The US Department of Defense closed the demonstration programme the following year.

AeroVironment has quietly continued development and built a second prototype.

In November, AeroVironment chief executive Timothy Conver described the Global Observer as a major growth opportunity for the company in about five years.

The Global Observer can fly for a week at altitudes above 60,000ft. The liquid hydrogen fuel packs more energy by volume than aviation-grade kerosene, but it is also more difficult to store and handle because of its volatility.

By operating in the stratosphere, the Global Observer is designed to function much like a geosynchronous satellite, providing communications or surveillance over a wide area over several days. By rotating vehicles, the Global Observer could provide long-term persistence.

“We’re increasingly optimistic about it,” Conver said during a corporate earnings call in November.

The Global Observer will compete for orders with the Boeing Phantom Eye, another liquid hydrogen-powered UAS with ultra-long endurance capability.