A New Generation of Homeland Missile Defense Interceptors

Recent Pentagon actions have produced considerable uncertainty in the future of homeland ballistic missile defense. In August 2019, Undersecretary of Defense for Research and Engineering Dr. Michael Griffin cancelled the Redesigned Kill Vehicle (RKV) program, a long-running effort to replace the kill vehicles on older Ground-Based Interceptors (GBI) designed to defend the nation from a long-range ballistic missile attack as part of the Ground-based Midcourse Defense (GMD) system. Two months later, the Missile Defense Agency (MDA) issued a Request for Information (RFI) to consider dividing the larger, underlying contract for the GMD program into as many as five parts and the circulation of draft proposals for an alternative Next Generation Interceptor (NGI). Besides thwarting the realization of deployment goals solidified by the 2019 Missile Defense Review, these decisions carry significant developmental, cost, and timing risk, drawing substantial congressional attention.

Figure 1

Q1: What was the RKV?

A1: The RKV was MDA’s previous program to upgrade the GMD kill vehicles, which are the part of the GBI designed to collide with the target warhead. The current Exoatmospheric Kill Vehicles (EKV) were deployed in the early 2000s and rely upon 1990s-era technology. Essentially advanced prototypes, the EKVs rely on complex and unique designs that create production and reliability issues—problems the RKV was designed to fix. MDA had planned to begin fielding RKV interceptors around 2023 and eventually phase out the older EKVs.

The RKV development was funded in the MDA Improved Homeland Defense Interceptors program. Between 2015 and 2019, MDA spent $1.7 billion on the Improved Homeland Defense Interceptors, and the 2020 President’s Budget requested an additional $412 million (Figure 2). In 2018, Congress added supplemental funds to accelerate RKV development and to deploy 20 additional GBIs, a goal reaffirmed by the Missile Defense Review. The 2020 budget suggested the program was on its way toward completion, with declining planned research and development expenditures in the next five years.

Figure 2

*Appropriated funds
**Future Years Defense Program estimates

Prior to its cancellation, there were several concerning indicators for the RKV. In March 2019, MDA announced a two-year delay in the RKV program after it failed assessments leading up to Critical Design Review. Undersecretary Griffin followed that decision by issuing a stop work order on May 24, initiating an analysis of alternatives of the path forward. On August 21, Griffin finally cancelled the RKV contract. Public reports pointed to the kill vehicle seeker, which guides the interceptor to its target, as the primary reason for the cancellation. The Government Accountability Office (GAO) previously noted combatant commander concerns about the RKV’s seeker and their interest in developing an alternative version to mitigate risk.

To replace the RKV, the Pentagon is now asking Congress to fund development of the NGI. According to press reports, MDA released a classified draft Request for Proposal (RFP) to industry on August 29, but the formal RFP has not yet been finalized.

Q2: How has Congress reacted?

A2: Because the RKV program was cancelled after three of the four defense committees had released their draft bills, the Senate Appropriations Committee was the only one to react formally to the cancellation. In their bill, released September 12, Senate appropriators recommended realigning $720 million across the 2019 and 2020 budgets to accommodate the NGI and the new path forward on GMD. Report language in the Senate appropriations bill hinting at the Pentagon’s larger plans to realign $12 billion over the next decade is consistent with the interest in restructuring the larger GMD contract. At $1.2 billion per year for the entire GMD enterprise, which includes operations and maintenance, procurement, and research to sustain current interceptors and systems, this proposal would not significantly change the budgetary footprint of the program. Senate appropriators also added around $532 million to extend the life of current interceptors and systems.

Prominent House members have added to a growing chorus asking questions about the RKV cancellation and its replacement. In an October 25 letter, the chair and ranking member of the House Armed Services Subcommittee on Strategic Forces, Representatives Jim Cooper (D-TN) and Mike Turner (R-OH), asked Pentagon leaders to justify the RKV termination, demonstrate how an analysis of alternatives was conducted, and explain the path forward for the NGI.

Failure to approve 2020 appropriations, potentially resulting in a long-term continuing resolution (CR), could also affect future GMD and NGI development. Although each bill is unique, CRs generally mean that funding for programs is frozen at roughly last year’s level. Should Congress adopt a year-long CR, the base GMD research and development account would receive around $803 million, $557 million less than the final Senate appropriations mark for 2020, impeding the ability to fund life extension programs found in the Senate appropriations bill (Figure 3).

Figure 3

Q3: What is the Pentagon’s current plan?  

A3: The Pentagon and Congress must now wrestle with both the long-term development path for the NGI and what to do in the short- and medium-term. Some reports suggest that the draft NGI plan would field new interceptors sometime in the 2030 timeframe meaning that the current 15-year-old interceptors would need life extension support for another decade. The longer timeline for NGI deployment presupposes the new program will invest in leap-ahead technology and attempt to outpace growing threats.

News reports about the NGI draft requirements suggest the competition will include upgrades to not just the kill vehicle but also to the booster that carries it, entirely replacing today’s GBIs. Rather than a single or unitary kill vehicle, reports also indicate that the NGI will likely carry multiple kill vehicles on each booster. As reported, the current path for NGI would in essence skip the RKV in favor of developing this volume kill capability.

Supporters of accelerating development efforts for multiple kill vehicle interceptors argue that future threat developments will likely require interceptors that can destroy multiple objects. More advanced adversary countermeasures could limit the ability of sensors to discriminate the lethal warhead from decoys, forcing the defense to destroy all the possible targets. Interceptors with multiple kill vehicles can target multiple lethal objects using a single booster rather than having to fire multiple interceptors.

On the other hand, skipping an RKV-like capability to deploy multiple kill vehicles could incur additional development risk. Putting multiple kill vehicles on a single booster requires a stable and reliable design that can be miniaturized and robust communications systems for the several kill vehicles. These efforts could build on the successful March 25 salvo test and advances in drone swarm technology, but combining the required technical leaps into a single program presents a major challenge.

Budgetary sustainability presents another risk for the current NGI plan. The Office of Management and Budget reportedly does not yet include the NGI in its 2021 budget plans, and Congress has repeatedly rejected plans to develop a Multi-Object Kill Vehicle (MOKV) alongside the RKV. Previous resistance to funding MOKV could be explained by a preference for the no longer available RKV option, but any multiple kill vehicle program will likely face significant scrutiny. A new NGI budget line may also require additional funding, a difficult problem for MDA considering its top line budget projects to fall over the course of the current Future Years Defense Project (FYDP). RKV funding was further projected to drop over the FYDP (Figure 2), so inserting a replacement program could create new tradeoffs.

Q4: Are there alternative paths forward?

A4: One alternative to the draft NGI concept would embrace the logic of the unitary RKV design while fixing its technical issues. After the RKV cancellation, Undersecretary Griffin emphasized that money spent on the project was not wasted but rather “went towards the acquisition of knowledge, which will inform our future.” Such a path could then build the NGI in a block or spiral manner, deploying new components as they are ready and eventually resulting in the more comprehensive capability. Without considerable time for redesign, such an interim step could develop either a new unitary kill vehicle or a small number of multiple kill vehicles.

The first step in this path would likely be solving the technical issues with the RKV. Considering the Pentagon’s previous consideration of an alternative seeker concept, this path may bear fruit relatively quickly. While this interim kill vehicle would still delay previous deployment deadlines, it would allow older kill vehicles to be replaced earlier than 2030 and serve as a hedge for NGI delays. Consistent with the general philosophy of the RKV, developing an interim kill vehicle could also be used as a test bed for kill vehicle to kill vehicle communications devices. It might also allow MDA to simplify the kill vehicle design, reducing technical risk and the cost of manufacturing future kill vehicles.

Nevertheless, an interim solution does invite longer-term risk if it inhibits the development of the more advanced capabilities envisioned for NGI. The history of GMD is littered with examples of pressure for immediate deployments curtailing investment in future capabilities. For example, the Bush administration prioritized building additional GBI capacity instead of sticking to its own plan for improvements, the Obama administration in turn cancelled the MOKV effort in 2009, and the Trump administration has now removed MOKV from its 2020 budget submission and cancelled RKV. Such a decision would also fit within the growing trends in MDA’s budget toward increased procurement and operations spending at the seeming expense of advanced research and development. Should the NGI stall as well, a unitary kill vehicle may not sufficiently address future threats.

Whatever path is ultimately chosen, the Pentagon and MDA must balance risks and potential benefits to determine a comprehensive approach for the future of homeland missile defense, both in the near- and long-term.

Wes Rumbaugh is a research associate with the Missile Defense Project at the Center for Strategic and International Studies (CSIS) in Washington, D.C.

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