WASHINGTON — The U.S. Missile Defense Agency is examining the possibility of building a layered ballistic missile defense architecture for the homeland that would bolster the current ground-based system in Alaska, all while a next-generation capability is developed and fielded.

The MDA featured its plan in its fiscal 2021 budget request, but there isn’t much of a strategy laid out in its fiscal 2022 funding picture. And so lawmakers want answers before turning on the funding spigot.

Developing such an architecture, even though it would use mostly proven systems, has many hurdles, as MDA Director Vice Adm. Jon Hill said last year.

The plan would include establishing layers of defensive capability relying on the Aegis Weapon System, particularly the SM-3 Block IIA missiles used in the system, and a possible Aegis Ashore system in Hawaii. The underlay would also include the Terminal High Altitude Area Defense system.

The layered approach would buy time while the Pentagon scrambles to field a new interceptor to replace older Ground-Based Interceptors — after canceling its effort to redesign the kill vehicle for the GBIs — in its Ground-based Midcourse Defense system located at Fort Greely, Alaska, and Vandenberg Space Force Base, California.

The agency cleared one hurdle in November 2020 with the successful test of the SM-3 Block IIA missile after several failed tests.

The test stressed the system, putting it up against a long-range intercontinental ballistic missile, but the MDA wants to conduct another yet-to-be-scheduled test against a more complex ICBM target with separation debris and countermeasures.

However, the validation of a possible underlay doesn’t stop with a few tests. Upgrades will be required based on threats; combat system certifications will need to be conducted; and work must be performed with the Navy to determine where Aegis ships should deploy, Hill said. The agency will also have to determine how quickly it can ramp up its production line for SM-3 Block IIA missiles.

Hill said last fall that if the agency succeeds with Aegis, it could go down the path with THAAD, then work on engagement coordination between layers.

When the FY22 budget request came out at the end of May, Hill said funding would focus on looking at how the Command and Control, Battle Management, and Communications system could incorporate Aegis and THAAD capabilities for the homeland, and how those systems would be linked to give options to combatant commanders.

But, he added, “those decision have not been made to date.”

When asked if the agency was cooling on a layered homeland defense, Hill said: “I wouldn’t say it’s no longer a priority since we do have investment in the budget, but there are some very serious policy implications, and so we want to make sure that we get the policy angles right.”

The agency also wants to make sure it’s still a need for U.S. Northern Command in light of a now-established service life extension program for the GMD’s Ground-Based Interceptors already emplaced, Hill noted. The command did not include layered homeland defense in its list of unfunded requirements sent to Congress in June.

“The big concern, back when layered homeland defense was first discussed, was the concern that the existing fleet would start to lose its reliability over time while we also had this timeline for the Next-Generation Interceptor off to the right,” Hill said.

Plans for the Next-Generation Interceptor are moving forward with a competition between Lockheed Martin and Northrop Grumman, and there’s talk the timeline for first emplacement could be earlier than anticipated.

Yet, Congress is getting impatient over a lack of answers regarding progress toward an architecture that could shore up any gap in capability now and into the future.

During a June 14 hearing with the House Armed Services Committee’s strategic forces subpanel, Rep. Elise Stefanik, R-N.Y., asked for an update on the report on the layered homeland defense system, which was required in the FY21 National Defense Authorization Act. She noted that the deadline of March 1, 2021, had passed.

Hill responded that, while there are no technical barriers to an underlay, “it’s really a policy question” that “we need to come through.”

Without offering a timeline for delivering a report to Congress, Leonor Tomero, the Pentagon’s assistant secretary of defense for nuclear and missile defense policy, said at the same hearing: “I can assure you that we are looking at what investments we make for a layered homeland defense, what priorities are the subject of studies again in consultation with the Missile Defense Agency and the Office of Cost Assessment and Program Evaluation.”

The Defense Department made an initial investment in FY22, Tomero added, and studies will inform further investments in FY23.

The Strategic Forces Subcommittee followed up in its markup of the FY22 authorization bill with a renewed push for a detailed report. The committee would direct the Pentagon to submit a report by the end of 2021 on development and deployment plans for using Aegis with SM-3 Block IIA interceptors as part of a layered missile defense system.

The report should include how Fort Drum, New York, previously identified as an East Coast location for Ground-Based Interceptors, might be used for future layered defense. Stefanik’s district includes Fort Drum.

An analysis of how deploying Arleigh Burke-class guided-missile destroyers for homeland defense would affect Navy readiness and global force management would also be required, and the report should contain an applicable manning strategy should land-based Aegis systems be deployed as part of the architecture.

The House Appropriations Committee’s defense subpanel, in its markup of the FY22 spending bill, took hacks at Defense Department funding applied to the layered homeland defense totaling $203.7 million.

The committee zeroed out Aegis BMD layered homeland missile defense development, cutting all $98.96 million for which the MDA had budgeted, and a total of $64.56 million to work on similar development for THAAD.

According to the MDA’s FY22 budget justification documents, the plan for developing Aegis for homeland defense includes refining system-level requirements and development to expand threat and mission space and to increase performance against moderate threats.

The committee noted the funding cut is due to a lack of validated requirements and acquisition strategy.

The Senate Armed Services Committee released a summary of its FY22 authorization bill, but aside from supporting the MDA’s pursuit of the NGI, there is nothing else signaling its intentions.

The Senate Appropriations Committee’s defense subpanel has yet to release its markup of the FY22 spending bill as of press time on Aug. 2.

Software and hardware improvements needed to evolve both THAAD and Aegis systems, “will be important to proceed irrespective of whether or not they end up deployed to support a thick defense of the continental United States,” Tom Karako, senior fellow with the International Security Program and the direct of the Missile Defense Project at the Center for Strategic and International Studies told Defense News.

“The non-recurring engineering planned for the ‘layered defense’ program elements would be very useful to complete to support regional applications,” he added. “These systems began as regional defenses, and their continued evolution will benefit regional protection, such as for bases in Guam, Japan, and the like.”

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.

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