WASHINGTON — Northrop Grumman has been selected to continue development on the Glide Phase Interceptor, a new missile defense asset designed to take down hypersonic weapons during the glide phase of the flight.

The program, a coproduction initiative between the US and Japan, is led by the US Missile Defense Agency. The work will continue under an existing Other Transaction Agreement (OTA), according to an MDA statement.

“Today’s decision represents a turning point for hypersonic glide phase defense,” Lt. Gen. Heath Collins, MDA director, said in the announcement. “I’m very proud of the entire team including our industry partners, for all the hard work to get to this point. It is also an honor to have Japan as our partner as we move forward on this critical counter-hypersonic capability.”

Northrop’s win comes over competitor RTX. Both firms were on contract to develop GPI in June 2022 after the elimination of another competitor, Lockheed Martin. The program began its “technology development” phase in April 2023.

The fiscal 2024 National Defense Authorization Act pushed MDA to ensure initial operational capability for GPI by the end of 2029 and full operational capability by 2032, as well as to deliver at least 24 GPIs by 2040. But MDA has consistently said GPI is aimed at countering threats beyond 2035, and Collins told the Senate Armed Services strategic forces subcommittee on May 8 that achieving the 2029 goal would be “very hard” and entail serious risks.

Exactly how the workshare with Japan will break down is still a point of negotiation, officials in Tokyo told Breaking Defense earlier this year. There, the defense ministry plans to spend 75.7 billion yen, or $480 million, for the GPI program this fiscal year. Northrop previously said that if it won the competition, it would split work with Japan on a 50-50 basis.

This story will be updated.