DARPA Unveils XRQ-73 in SHEPARD Program for Next-Generation Unmanned Aircraft

The Defense Advanced Research Projects Agency (DARPA) has announced that the Series Hybrid Electric Propulsion AiRcraft Demonstration (SHEPARD) programme aircraft received its official designation, XRQ-73.

The SHEPARD program aims at revolutionizing long-endurance unmanned aerial systems (UAS). This program, dubbed an "X-prime" effort by DARPA, intends to rapidly develop and deploy a novel aircraft capable of extended operational durations, with initial flight anticipated by late 2024.

SHEPARD builds upon technologies pioneered in the earlier Air Force Research Laboratory/Intelligence Advanced Research Projects Activity (AFRL/IARPA) Great Horned Owl (GHO) project, which led to the development of the XRQ-72. The program is spearheaded by prime contractor Northrop Grumman, in collaboration with key suppliers including Scaled Composites, Cornerstone Research Group, Brayton Energy, PC Krause and Associates, and EaglePicher Technologies. Contributions from AFRL and the Office of Naval Research (ONR) further bolster the initiative.

"The SHEPARD program aims to mitigate integration risks associated with emerging technologies, focusing on a specific propulsion architecture and power class tailored for Department of Defense missions," remarked Steve Komadina, SHEPARD program manager. "By leveraging series hybrid electric propulsion, we anticipate significant benefits in endurance, operational flexibility, and reduced environmental footprint."

The XRQ-73 aircraft, designated as a Group 3 UAS under U.S. military classification, is projected to weigh approximately 1,250 pounds (567 kg). Designed with a stealthy flying wing configuration, the aircraft features tapered wingtips and dual air inlets on its upper fuselage, suggesting compatibility with advanced sensor payloads.

While specifics on performance metrics remain confidential, Group 3 UAS typically operate within a range conducive to intelligence, surveillance, and reconnaissance (ISR) missions, offering operational altitudes between 3,500 feet and FL180 and speeds ranging from 100 to 250 knots. The hybrid electric propulsion system promises quieter operations, enhanced fuel efficiency, and reduced emissions, critical advantages for ISR roles where stealth and extended endurance are paramount.

The SHEPARD program represents a strategic advancement over its predecessor, the XRQ-72, which showcased a smaller footprint and similar design principles focused on ultra-quiet reconnaissance capabilities. Initial reports suggest the XRQ-73 will surpass its predecessor in size and capability, although specific dimensions have yet to be disclosed.