The U.S. Air Force 53rd Wing on June 14 tested the Northrop Grumman [NOC] Radar Aided Targeting System (RATS)–a system for improving the Northrop Grumman B-2 stealth bomber’s weapon guidance accuracy in GPS-degraded environments, the 53rd Wing said.

Last month’s test, held at Tonopah Test Range, Nev., featured a B61-12 Joint Test Assembly (JTA).

The B61-12 will eventually replace the B83 and four previous B61 variants in the nuclear arsenal.

The non-profit, Washington-based Federation of American Scientists estimates that the National Nuclear Security Administration will make about 480 B61-12s, which are to include a GPS guidance tail kit by Boeing [BA].

RATS “significantly improves the ability to accurately employ near-precision weapons without the need for GPS,” Northrop Grumman said in an email response to questions. “RATS is a key element of the B-2 nuclear modernization, as GPS may not be available during a bomber task force mission. RATS will provide north, east, and down offset coordinates to the platform based on the aircrew’s radar designation, requiring only one image per target.”

Air Force Capt. David Durham, the 72nd Test and Evaluation Squadron’s B-2 weapons flight commander, said in the 53rd Wing’s statement that the June 14 test was the first release of a production unit of the B61-12 JTA.

“Future B61-12 JTA releases will be conducted during annual Weapon System Evaluation Program flight tests as part of Department of Energy/National Nuclear Security Administration and Department of Defense surveillance tests,” the 53rd Wing said.

The technology maturation and risk reduction phase of the RATS program began in October 2018, and the Engineering and Manufacturing Development phase began in August 2019. Northrop Grumman said that the Air Force started fielding RATS this year and that RATS is one of three new capabilities within integrated functional capability 6.4 that the Air Force certified last year.

Before the June 14 test, Northrop Grumman said that there were five RATS developmental flight tests and two operational flight tests.