While the U.S. Air Force said this month that it had, for the first time, flight tested collaborative weapons under the service’s Golden Horde program–one of three service Vanguard efforts, the Air Force is also pursuing a scaled-down Gray Wolf low-cost cruise missile prototype.

More than two years ago, the Air Force Research Laboratory’s (AFRL) Gray Wolf program consisted of four spiral-development phases to develop and field a $100,000 cruise missile that could act in swarms to defeat enemy air defenses. Plans called for multiple options from decoy to electronic attack to long range high-explosive warheads against peer adversaries.

Lockheed Martin [LMT] and Northrop Grumman [NOC] held five-year, $110 million contracts to develop the missile, to be tested first on F-16 fighters and compatible with F-35, F-15, F-18, B-1, B-2 and B-52 aircraft. But the Air Force decided two years ago to shift funds away from the Lockheed Martin proposal to kick start Golden Horde.

Due to lack of a funding for spirals two through four, AFRL narrowed the scope of the effort to Northrop Grumman’s involvement in spiral one, and the latter is to finish in the coming months.

Last year, the Air Force said that the Gray Wolf TDI-J85 turbojet engine by Kratos‘ [KTOS] Michigan-based Technical Directions, Inc. (TDI) had a series of flight tests with “multiple inflight windmill starts and operation at high altitude.” In June, an F-16 from the 416th Flight Test Squadron at Edwards AFB, Calif., also conducted a captive carry flight test of the missile.

“Our current effort will flight test the Northrop Grumman air frame and TDI engine but no additional work is funded,” per an email from AFRL’s Gray Wolf program manager, Maj. Adam Corley, and James Sumpter, AFRL’s WeaponONE program manager.

WeaponONE is using artificial intelligence/machine learning (AI/ML)-aided digital twins to improve the performance of Gray Wolf.

“Spiral 1 [of Gray Wolf] demonstrates the design and manufacturing capabilities required to build a low cost cruise missile,” per Corley and Sumpter. “It pulls together various technologies such as a low-cost turbine engine, composite manufacturing for the body, and low cost sub-components to deliver a missile with a low cost and conduct a successful flight test.  Subsequent spirals would have added collaborative functions via radios and software changes to demonstrate a swarm of 4-6 missiles with collaborative flight behaviors and, lastly, the final spiral was to add various payload packages making the Gray Wolf adaptable to any mission requirement.”

The Gray Wolf program used AFRL’s Weapon Open System Architecture “to make the payload bay open with available power and space for any number of payload options,” Corley and Sumpter wrote. “While Spiral 1 will not incorporate a payload, the system can be adapted to carry warheads, submunitions, sensors, collaborative radios, Electronic Warfare or Electronic Attack packages, or a combination of these payloads.”

For its part, Golden Horde is to integrate datalink radios and demonstrate the ability of a “swarm” of networked weapons systems “to collaborate to decrease target error and defeat targets while adapting to changes in the field,” AFRL said. “The program is to mark a change from the typical pre-designated missions of weapon systems to missions using a Playbook of set plays under defined Rules of Engagement.”

Last month, the Golden Horde program marked a signature event, as an F-16 released two Collaborative Small Diameter Bombs (CSDBs) in what the Air Force called the first-ever flight demonstration of collaborative weapons (Defense Daily, Jan. 7).

At least two other flight tests are likely this year.

The CSDBs use technology developed by AFRL and California-based Scientific Applications and Research Associates, Inc. (SARA), which received a $100 million contract for CSDB-I in 2019. As part of Golden Horde, Georgia Applied Research Corp. (GTARC) also received an $85 million contract for a Collaborative Miniature Air-Launched Decoy (CMALD) in 2019.

AFRL plans called for a collaboration this fall between CSDB-I and CMALD to defeat simulated targets, but AFRL recently decided not to pursue that demonstration but to shift toward a more generic approach that does not feature specific weapons in keeping with congressional concern about Golden Horde being too mature a program to receive science and technology (S&T) funding.

CSDBs are 250-pound Boeing [BA] GBU-39 Small Diameter Bombs modified with a collaborative autonomy payload to locate and prioritize targets. AFRL said that, during last month’s CSDB test flight, the two CSDBs “quickly established communication with each other and their seekers detected a GPS jammer.”

“During the mission, the weapons referred to pre-defined Rules of Engagement (RoEs), a set of constraints preloaded by a mission planner, and determined that the jammer was not the highest priority target,” AFRL said. “The weapons then collaborated to identify the two highest priority targets. However, due to an improper weapon software load, the collaboration guidance commands were not sent to the weapon navigation system. Without the updated target locations, the weapons impacted a fail-safe target location.”

While the weapon software load failed, the flight demonstration of CSDB marks “an important step on the path to Networked Collaborative Weapon systems,” Chris Ristich, director of AFRL’s Transformational Capabilities Office (TCO), said in a statement.