The U.S. Air Force has awarded RTX [RTX]’s missiles and defense business in Tucson, Ariz., a nearly $408 million contract for the Hypersonic Attack Cruise Missile Southern Cross Integrated Flight Research Experiment (HACM-SCIFiRE) with Australia.

“Work will be performed at Tucson, Arizona, and is expected to be completed by Dec. 31, 2028,” DoD said in a Dec. 21 contract announcement.

In September last year, the Air Force awarded RTX–then Raytheon–a $985 million contract for HACM (Defense Daily, Sept. 22, 2022). The company beat out Lockheed Martin [LMT] and Boeing [BA] for the award.

Air Force Secretary Frank Kendall has said that scramjet engine-propelled, air-breathing hypersonic weapons, such as HACM, have shown more promise than hypersonic glide vehicle missiles.

The Air Force awarded three 15-month SCIFiRE contracts in June 2021 to Boeing, Lockheed Martin, and Raytheon to complete preliminary designs of an air-breathing hypersonic cruise missile.

After last year’s $985 million award to Raytheon, the Air Force said that it would field HACM by fiscal 2027 and that the HACM program “will now operationalize the Raytheon SCIFiRE prototype design for fighter aircraft integration and deliver two leave-behind assets with operational utility.”

Northrop Grumman [NOC] is building the scramjet engine for HACM.