AeroVironment Global Observer

A Global Observer prototype, called "Odyssey," flew in May 2005. It had a 50 ft (15 m), one-third the size of the planned full-sized version, and ran solely on hydrogen fuel-cells powering electric motors that drove eight propellers, flying the aircraft for several hours. The JCTD started in September 2007.[2][3] In August 2010, Aerovironment announced that the full-sized Global Observer wing had passed wing load testing. The 53 m (175 ft) all-composite wing, which comes in five sections and is designed to maximize wing strength while minimizing weight, had loads applied to it that approximated the maximum loads it is designed to withstand during normal flight, turbulence and maneuvers. In its third year of testing, the demonstrator had also undergone ground and taxi tests as well as taken a "short hop" lifting off the ground briefly during taxiing.[4][3]

The Global Observer performed its first flight on 5 August 2010, taking off from Edwards AFB and reaching an altitude of 4,000 ft (1,200 m) for one hour. The flight was performed using battery power.[5] The aircraft completed initial flight testing, consisting of multiple low-altitude flights, at Edwards AFB in August and September 2010. This phase used batteries to power the hybrid-electric aircraft and approximate full aircraft weight and center of gravity for flight control, performance, and responsiveness evaluation. Following this, the program team installed and ground tested the aircraft's hydrogen-fueled generator and liquid hydrogen fuel tanks which will power it for up to a week in the stratosphere.[6]

The first flight of the Global Observer using hydrogen fuel occurred on 11 January 2011, reaching an altitude of 5,000 ft (1,500 m) for four hours.[7] On 1 April 2011, Global Observer-1 (GO-1), the first aircraft to be completed, crashed 18 hours into its 9th test flight. AeroVironment said it was undergoing flight test envelope expansion and had been operating for nearly twice the endurance and at a higher altitude than previous flights when the crash occurred. At the time, the second aircraft developed as part of the JCTD program was nearing completion at a company facility; the $140 million program was originally scheduled for completion in late 2011, but the crash delayed this by a year. AeroVironment was looking for sources of incremental funding to provide a bridge between the demonstration and a future procurement program.[8][9][10]

In December 2012, the Pentagon closed the development contract for the Global Observer, the reason being the crash in April 2011. The Global Observer was used as a technology demonstration, not a program for a functioning aircraft. In April 2013, the Pentagon stated that no service or defense agency had advocated for it to be a program. AeroVironment is currently in possession of the second prototype Global Observer.[11] On 6 February 2014, AeroVironment announced that it had teamed with Lockheed Martin to sell the Global Observer to international customers. The partnership is focused around building "atmospheric satellite systems" around the UAV. The Global Observer may compete for orders with the Boeing Phantom Eye liquid hydrogen-powered long endurance UAV.[12][13]

• Endurance: 5–7 days
• Payload: Up to 400 lbs (180 kg)
• Operating altitude: 55,000–65,000 feet (17,000–20,000 m)
• Propulsion system: Liquid hydrogen-powered internal combustion power plant driving four high efficiency electric motors. The aircraft does not produce carbon emissions.
• Wing Span: 175 feet (53 m)
• Length: 70 feet (21 m)
• Launch/Recovery Method: Operate from conventional 150 ft (46 m) W X 6,000 ft (1,800 m) long paved runways (<4,200 ft takeoff and landing distance)

• Vulture (UAV)
• QinetiQ Zephyr
• Boeing HALE
• Air Strato

• Stratospheric Persistent UAS: Global Observer Archived 2010-06-06 at the Wayback Machine
• Edwards Air Force Base photo of Global Observer HALE UAS