The Army has concluded a demonstration with Airbus’ ultra-long endurance, solar-powered Zephyr unmanned air system (UAS) after flying for a record-breaking 64 straight days, noting the system experienced an “unexpected termination” over Yuma Proving Ground in Arizona.

Army Futures Command said all further flight tests with the Zephyr UAS have been postponed to 2023, citing the amount of data to be analyzed from the demonstration and steps to investigate what led to the system’s termination.

Zephyr UAS. Photo: Airbus.

“Our team is working hard to gather and analyze important data following the unexpected termination of this flight,” Michael Monteleone, director of the Army’s Assured Positioning, Navigation and Timing (APNT)/Space Cross-Functional Team (CFT), said in a statement. “Despite this event, the Army and its partners have gleaned invaluable data and increased knowledge on the endurance, efficiency, and station keeping abilities of high-altitude UAS platforms. That knowledge will allow us to continue to advance requirements for reliable, modernized stratospheric capabilities to our soldiers.”

The Army noted that there were no injuries or risk to personnel or other aircraft as a result of the events that led to the system’s unexpected termination over Yuma Proving Ground, and that further information will be released following the investigation.

Futures Command first detailed the APNT/Space CFT’s work with the Zephyr UAS in July, noting the system had launched on June 15 and had already broken its own previously-set world record for longest duration UAS flight of 26 hours (Defense Daily, July 22). 

The Army previously said the demonstration was intended to test the system’s “energy storage capacity, battery longevity, solar panel efficiency and station-keeping abilities.”

Futures Command had said a second flight was expected in the coming weeks where Zephyr would be launched and travel over the Pacific Ocean and include demonstration of an Army -developed prototype payload. That demonstration is now likely postponed following details of the system’s unexpected termination.

During the 64-day flight, Futures Command said the Zephyr UAS reached 60,000 feet into the stratosphere and its path included traversing over the southern portion of the U.S., into the Gulf of Mexico and over South America. 

“This flight marked a number of firsts for Zephyr 8, including its departure from U.S. airspace, flight over water, flight in international airspace, data collection and direct downlink while outside of U.S. airspace, the longest continuous duration (7 days) utilizing satellite communications, and the demonstration of resilient satellite command and control from three different locations – Huntsville, Ala.; Yuma, Ariz., and Farnborough, U.K.,” the Army wrote. “This experimentation successfully demonstrated Zephyr’s energy storage capacity, flight endurance, station-keeping and agile positioning abilities.”

Ret. Army Gen. Stephen Townsend, who retired from his post as the leader of U.S. Africa Command earlier this month, told reporters before he left he would be interested in seeing more “long-dwell, long-duration ISR capabilities” utilized in AFRICOM, specifically citing the ongoing work with the Zephyr UAS (Defense Daily, Aug. 4). 

“I would be happy to volunteer for any pilot programs that folks want to propose out there in Africa,” Townsend said at the time. “[Zephyr UAS] is a high-altitude, solar-powered glider. I can just imagine having that capability on the African continent. It would be fantastic.”