Early this year, the Pentagon issued a memo halting development of a new radar meant to protect Guam from high-end air and missile threats, according to a May 22 Government Accountability Office report on the effort to protect the strategic island in the Pacific.
“On January 7, 2025, the Deputy Secretary of Defense [Kathleen Hicks] directed the [Missile Defense Agency] to cease development of one of the elements, the AN/TPY-6 radar, but to retain the currently fielded panel as an experimental asset with potential to develop for operational use within the [Guam Defense System] in the future,” the report states.
While Hicks’ decision came at the end of her tenure under the Biden administration, GAO notes the changes are not binding on the new administration.
The Pentagon’s plan to develop an elaborate air-and-missile defense architecture is beginning to take shape and will be pieced together over the coming years in order to protect Guam from increasingly complex threats emerging in China and North Korea.
MDA had shipped its first AN/TPY-6 panel on a boat headed to the island last summer, planning to use it to track a threat launched from a C-17 plane in a first flight test of current capability coming together for the defense of Guam at the end of 2024.
The new radar uses technology from MDA’s Long-Range Discrimination Radar positioned in Alaska at Clear Space Force Base, which will have its own test next year ahead of declaring operational capability.
The Guam Defense System will also rely on a variety of systems still in development, mostly within the Army. The Navy will provide technology and capability from its Aegis weapons system. The land service plans to bring to Guam currently fielded capabilities, like the Patriot system and its Integrated Battle Command System, or IBCS, that connects any sensor and shooter together on the battlefield, as well as Mid-Range Capability missile launchers, which were first fielded at the end of 2023.
The Army will also incorporate Patriot’s radar replacement, the Lower Tier Air and Missile Defense Sensor, or LTAMDS, which was just approved for production, and its Indirect Fire Protection Capability launchers, which are reaching the end of the prototyping phase.
With the termination of AN/TPY-6, for now, Hicks directed the MDA prioritize remaining Aegis Guam systems development funds “toward delivering minimum viable Aegis C2 [command and control] and datalink capabilities to enable Standard Missile 6 (SM-6) engagements off remote track from AN/TPY-2 and LTAMDS over the JTMC [Joint Track Management Capability] bridge,” according to GAO’s report.
The Pentagon’s memo required upgrading the JTMC bridge to address all missile threats from China and achieve a Joint Tactical Integrated Fire Control capability — the future joint track architecture for Guam — “for coordinated battle management, combat identification and electronic protection,” the report states. Those upgrades should be completed no later than 2029.
The memo also directed MDA to accelerate key command-and-control integration work, including getting the Army-operated Terminal High Altitude Area Defense, or THAAD, system to work within IBCS.
Guam is home to a permanent THAAD battery called Task Force Talon, which serves as the critical component for defending the island against ballistic missile threats.
Additionally, the Army and MDA “shall integrate AN/TPY-2 measurement data into IBCS no later than 2030 and achieve full integration by 2033,” the report details.
The MDA has long used AN/TPY-2 radars to track ballistic missiles, but Raytheon just delivered a new version to MDA with Gallium Nitride, or GaN, which gives it the ability to track more complex threats at greater ranges like hypersonic weapons.
The first new radar with GaN will go to the Army’s eight THAAD battery. The radars can be used in a forward-based mode, providing cuing data to systems like the Navy’s Aegis ballistic missile defense system or the Army’s Patriot. It serves as the primary radar for THAAD.
The Army’s new LTAMDS radar, also developed by Raytheon, has GaN technology as well.
Jen Judson is an award-winning journalist covering land warfare for Defense News. She has also worked for Politico and Inside Defense. She holds a Master of Science degree in journalism from Boston University and a Bachelor of Arts degree from Kenyon College.