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Missile Defense: Fiscal Year 2020 Delivery and Testing Progressed, but Annual Goals Unmet

GAO-21-314 Published: Apr 28, 2021. Publicly Released: Apr 28, 2021.
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Fast Facts

A network of sensors and interceptor missiles forms the backbone of the U.S. Missile Defense System. DOD's Missile Defense Agency designed this system to protect the U.S., its military forces, and allies from missile attacks.

This year, the Missile Defense Agency delivered 62% of the interceptors it planned to, and conducted some tests (2 of 9) that provided valuable information. But this progress fell short of agency goals for asset delivery and annual testing. The Missile Defense Agency has a history of not completing planned tests, which results in less data than optimal to make sure missile defense capabilities work as intended.

A missile defense system flight test in October 2020

a missile being launched

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What GAO Found

In fiscal year 2020, the Missile Defense Agency (MDA) made progress toward achieving its delivery and testing goals for some of the individual systems—known as elements—that combine and integrate to create the Missile Defense System (also known as the Ballistic Missile Defense System). However, MDA did not complete its overall planned deliveries or annual testing. The figure below shows MDA's progress delivering assets and conducting flight tests against its fiscal year 2020 plans.

Percentage of Missile Defense Agency Planned Deliveries and Flight Tests Completed for Fiscal Year 2020

Percentage of Missile Defense Agency Planned Deliveries and Flight Tests Completed for Fiscal Year 2020

Deliveries— In fiscal year 2020, MDA delivered many assets it had planned. Specifically, MDA was able to deliver 82 missile interceptors for 3 elements. However, MDA was not able to deliver all planned interceptors, including one originally planned for 2018 for the Ground-based Midcourse Defense program, as the program experienced delays related to qualifying parts from a new supplier.

Flight testing— MDA conducted two planned flight tests, but neither was successful. The issues were due to problems with non-MDA assets, but the agency was able to collect important data. In addition, COVID-19 restrictions also affected the planned schedule. However, the delays continue a trend of MDA's inability to conduct planned annual flight testing, resulting in assets and capabilities that are subsequently delayed or delivered with less data than planned.

Ground testing— In fiscal year 2020, MDA continued to implement a new ground testing approach that the agency began in fiscal year 2019. In addition, MDA successfully completed three planned ground tests demonstrating defense capabilities for the U.S., U.S. forces and regional allies. However, MDA delayed two other ground tests to future fiscal years and expects disruptions in fiscal year 2021, in part due to ongoing COVID-19 disruptions.

Cyber— Despite failing to meet annual operational cybersecurity assessments since 2017, MDA canceled its planned fiscal year 2020 operational assessments, instead taking steps to implement a new approach designed to improve cyber system requirements while streamlining cyber test planning. It is premature to assess whether this new approach will achieve its intended goals.

Why GAO Did This Study

For over half a century, the Department of Defense has funded efforts to defend the U.S. from ballistic missile attacks. This effort consists of diverse and highly complex land-, sea-, and space-based systems and assets located across the globe. From 2002 through 2019, MDA—the agency charged with developing, testing, integrating, and fielding this system of systems—received about $162.5 billion. The agency also requested about $45 billion from fiscal year 2020 through fiscal year 2024.

In fiscal year 2020, MDA's mission broadened to include evolving threats beyond ballistic missiles such as defending against hypersonic missile attacks. With the inclusion of non-ballistic missile threats, the Ballistic Missile Defense System is in the process of transitioning to the Missile Defense System.

Congress included a provision in statute that GAO annually assess and report on MDA's progress. This, our 18th annual review, addresses the progress MDA made in achieving fiscal year 2020 delivery and testing goals.

GAO reviewed planned fiscal year 2020 baselines, along with program changes due to COVID-19 restrictions, and other program documentation and assessed them against responses to GAO detailed question sets and program and baseline reviews. GAO also interviewed officials from MDA and various Department of Defense Combatant Commands.

We do not make any new recommendations in this report but continue to track the status of prior recommendations.

For more information, contact John D. Sawyer at (202) 512-4841 or

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