Air Defense

Ground-based Midcourse Defense

Also known as
  • GMD
  • Ground-based Missile Defense
  • Ground-based Midcourse Defense system
  • GMD Weapon System

Ground-based Midcourse Defense (GMD) is the U.S. homeland ballistic missile defense system built around silo-launched Ground-Based Interceptors, missile-defense command networks, and long-range sensor inputs. Boeing has led GMD integration since 1998, while Army operators and MDA test reporting show the system's current public record is readiness testing and homeland-defense alert posture rather than documented combat employment.

Ground-based Midcourse Defense, Ground-based ballistic missile defense system, Air Defense
Image source: U.S. Army FTG-12 article
Profile / Specs

Profile

Origin
United States
Built by
Boeing
Type
Ground-based ballistic missile defense system
Service note
1998-present
Produced
1998-present

Specifications

Mission
Homeland defense against long-range ballistic-missile threats
Lead integrator
Boeing
Interceptor sites
Fort Greely, Alaska, and Vandenberg Space Force Base, California
Interceptor type
Silo-launched Ground-Based Interceptor with exoatmospheric hit-to-kill kill vehicle
Command and control
C2BMC provides GMD engagement-support and composite threat-track functions
Sensor modernization
LRDR supports long-range ballistic-missile detection, tracking, and discrimination for homeland defense
Modernization path
Next Generation Interceptor is planned as the future GMD interceptor
Variants

GMD is an integrated system rather than a single missile model; public sources most clearly distinguish current Ground-Based Interceptor configurations and the planned Next Generation Interceptor modernization path.

VariantConfigurationDesignation notes
Ground-Based Interceptor with CE-II Block 1 EKVUpgraded operational interceptor configuration

The FTG-12 test used an upgraded Ground-Based Interceptor with a Capability Enhanced-II Block 1 Exoatmospheric Kill Vehicle and demonstrated three-stage hardware operating in two-stage mode.

Sources: U.S. Army FTG-12 article

Next Generation Interceptor (NGI), Ground-launched ballistic missile interceptor, Air DefenseNext Generation Interceptor (NGI)Planned GMD interceptor modernization

Lockheed Martin describes NGI as a tip-to-tail interceptor inside the GMD system, and GAO describes NGI as the Defense Department's effort to improve homeland missile defense against increasingly capable threats.

Sources: Lockheed Martin NGI product page, GAO NGI Program Report

Command-And-Control Link

GMD depends on battle-management support from the missile-defense command network.

Compatible itemItem typeCompatibility evidence
C2BMC, Ballistic missile defense command-and-control system, Support EquipmentC2BMCBattle-management system

Lockheed Martin says a C2BMC upgrade augments engagement support for the Ground-based Midcourse Defense system and provides a single real-time composite picture of threat tracks.

Sources: C2BMC multi-domain upgrade

Interceptor Modernization

The current system uses Ground-Based Interceptors, while NGI is the planned next interceptor path for the same homeland-defense mission.

Compatible itemItem typeCompatibility evidence
Next Generation Interceptor (NGI), Ground-launched ballistic missile interceptor, Air DefenseNext Generation Interceptor (NGI)Ground-launched ballistic missile interceptor

Lockheed Martin describes NGI as a modern interceptor within GMD that is intended to protect against evolving long-range ballistic-missile threats.

Sources: Lockheed Martin NGI product page

Discrimination Sensor Link

Long-range sensor quality is central to the homeland-defense mission because the interceptor must discriminate a target during the midcourse phase.

Compatible itemItem typeCompatibility evidence
Long Range Discrimination Radar, Long-range ballistic-missile discrimination radar, Air DefenseLong Range Discrimination RadarLong-range ballistic-missile discrimination radar

Lockheed Martin describes LRDR as operational, ready to defend the U.S. homeland, and important to the effectiveness of ground-based interceptors.

Sources: Long Range Discrimination Radar product page

Architecture And Test Context

GMD is best read as a defensive architecture: interceptors, battle-management software, operators, and discrimination sensors must all line up before an engagement.

LayerSource-backed context
InterceptorsBoeing says Ground-Based Interceptors are the only operationally deployed missile component of GMD; the FTG-12 test used an upgraded GBI with a CE-II Block 1 kill vehicle.
OperatorsThe U.S. Army account of FTG-12 says 100th Missile Defense Brigade soldiers conducted the interceptor launch and support U.S. Northern Command's homeland-defense mission.
Fire controlC2BMC modernization is described as improving GMD engagement support and shared threat-track presentation.
Sensor discriminationLRDR is described as operational and as improving the effectiveness of ground-based interceptors by detecting and tracking ballistic-missile threats.
Public use statusPublic sources support live-fire testing and alert posture rather than combat employment; the Army FTG-12 account quotes an operator saying GMD had not been needed operationally.

Sources: Boeing GMD feature; U.S. Army FTG-12 article; C2BMC multi-domain upgrade; Long Range Discrimination Radar product page.

Timeline

Ground-based Midcourse Defense Key Events

  1. Boeing begins GMD integration role

    Boeing says it has been the lead integrator for the Ground-based Midcourse Defense system since 1998.

    Sources: Boeing GMD feature

  2. Additional interceptors delivered to Fort Greely

    Boeing reported delivery of two additional Ground-Based Interceptors to the Missile Defense Agency at Fort Greely, Alaska.

    Sources: Boeing GMD feature

  3. FTG-12 demonstrates two-stage GBI mode

    MDA and Army operators conducted FTG-12 at Vandenberg Space Force Base, using an upgraded GBI with a CE-II Block 1 kill vehicle to intercept an intermediate-range ballistic-missile target.

    Sources: U.S. Army FTG-12 article, DVIDS FTG-12 intercept image

  4. GAO reviews the NGI modernization program

    GAO reported on the Next Generation Interceptor program as a major Defense Department effort to improve the GMD system against increasingly capable missile threats.

    Sources: GAO NGI Program Report

  5. LRDR enters operational homeland-defense role

    Lockheed Martin describes the Long Range Discrimination Radar as operational and as a sensor that helps ensure the effectiveness of ground-based interceptors.

    Sources: Long Range Discrimination Radar product page

Media

Ground-based Midcourse Defense Videos

Ground-based Midcourse Defense Images

Ground-based Midcourse Defense, Ground-based ballistic missile defense system, Air Defense - view 1
Source: U.S. Army FTG-12 article
Ground-based Midcourse Defense, Ground-based ballistic missile defense system, Air Defense - view 2
Source: U.S. Army FTG-12 article
Related Weapon Systems
Next Generation Interceptor (NGI), Ground-launched ballistic missile interceptor, Air DefenseAir DefenseNext Generation Interceptor (NGI)Ground-launched ballistic missile interceptorNext Generation Interceptor (NGI) is Lockheed Martin's planned homeland ballistic missile interceptor for the U.S. Missile Defense Agency's Ground-based Midcourse Defense system. The program moved from competing 2021 development awards to a 2024 Lockheed Martin downselect and a 2026 Courtland production facility, with public sources emphasizing multiple kill vehicles, solid-rocket propulsion, in-flight communications upgrades, and schedule risk around the original 2028 fielding target.
Harpoon Coastal Defense System (HCDS), Mobile coastal anti-ship missile system, Naval SystemsNaval SystemsHarpoon Coastal Defense System (HCDS)Mobile coastal anti-ship missile systemHarpoon Coastal Defense System (HCDS) is a land-based Harpoon launch-system package built around mobile launcher transporter units, radar trucks, command-and-launch equipment, and RGM-84L-4 Harpoon Block II missiles. U.S. records identify Boeing as the principal contractor for Taiwan's HCDS sale, document follow-on launcher and missile-package contracts, and separately record two Harpoon coastal defense systems funded for Ukraine after Russia's full-scale invasion.

Sources

Boeing GMD featurePublisher: Boeing | Note: Supports Boeing's lead-integrator role, the Fort Greely delivery context, the system's all-50-states homeland-defense role, Ground-Based Interceptors as GMD's operational missile component, and prior Boeing image provenance. | Accessed: 2026-06-29C2BMC multi-domain upgradePublisher: Lockheed Martin | Note: Supports the C2BMC engagement-support upgrade for Ground-based Midcourse Defense and the single real-time composite picture description. | Accessed: 2026-06-29U.S. Army FTG-12 articlePublisher: U.S. Army | Note: Supports the FTG-12 test date and location, the 100th Missile Defense Brigade operator role, the CE-II Block 1 EKV and two-stage-mode details, the public statement that GMD had not been needed operationally, and official MDA image provenance. | Accessed: 2026-06-29DVIDS FTG-12 intercept imagePublisher: DVIDS / Missile Defense Agency | Note: Public-domain DVIDS image page supporting the FTG-12 intercept imagery and the upgraded GBI intercepting an intermediate-range ballistic-missile target on December 11, 2023. | Accessed: 2026-06-29DVIDS FTG-12 target imagePublisher: DVIDS / Missile Defense Agency | Note: Public-domain DVIDS image page supporting the FTG-12 target-launch gallery image. | Accessed: 2026-06-29Lockheed Martin NGI product pagePublisher: Lockheed Martin | Note: Supports NGI as a tip-to-tail interceptor within the Ground-based Midcourse Defense system and the planned integration of NGI into the GMD homeland-defense mission. | Accessed: 2026-06-29GAO NGI Program ReportPublisher: U.S. Government Accountability Office | Note: Supports NGI oversight context for improving GMD against increasingly capable ballistic-missile threats. | Accessed: 2026-06-29Long Range Discrimination Radar product pagePublisher: Lockheed Martin | Note: Supports LRDR as an operational homeland-defense radar that detects and tracks ballistic-missile threats and helps ensure ground-based interceptor effectiveness. | Accessed: 2026-06-29