Ground-Based Midcourse Defense


Ground-Based Midcourse Defense is the United States' anti-ballistic missile system for intercepting incoming warheads in space, during the midcourse phase of ballistic trajectory flight. It is a major component of the American missile defense strategy to counter ballistic missiles, including intercontinental ballistic missiles carrying nuclear, chemical, biological or conventional warheads. The system is deployed in military bases in the states of Alaska and California; in 2018 comprising 44 interceptors and spanning 15 time zones with sensors on land, at sea, and in orbit. In 2019, a missile defense review requested that 20 additional ground-based interceptors be based in Alaska.
GMD is administered by the U.S. Missile Defense Agency, while the operational control and execution is provided by the U.S. Army, and support functions are provided by the U.S. Air Force. Previously known as National Missile Defense, the name was changed in 2002 to differentiate it from other U.S. missile defense programs, such as space-based and sea-based intercept programs, or defense targeting the boost phase and reentry flight phases. The program was projected to have cost $40 billion by 2017. That year, the MDA scheduled its first intercept test in three years in the wake of North Korea's accelerated long-range missile testing program.

Description

The system consists of ground-based interceptor missiles and radar which would intercept incoming warheads in space. Boeing Defense, Space & Security is the prime contractor of the program, tasked to oversee and integrate systems from other major defense sub-contractors, such as Computer Sciences Corporation and Raytheon.
The key sub-systems of the GMD system are:
Interceptor sites are at Fort Greely, Alaska and Vandenberg Air Force Base, California. A third site was planned for a proposed US missile defense complex in Poland, but was canceled in September 2009.
In December 2008, the U.S. Missile Defense Agency awarded Boeing a $397.9 million contract to continue development of the program.
In March 2013, the Obama administration announced plans to add 14 interceptors to the current 26 at Fort Greely in response to North Korean threats. The deployment of a second TPY-2 radar to Japan was announced at the same time. While President Obama said that the additional deployment was a hedge against unexpected capabilities, Chinese Ministry of Foreign Affairs spokesman Hong Lei complained that the additional defenses would affect the global strategic balance and strategic trust. In late 2013, there were plans for a proposed Eastern United States missile defense site to house a battery of these missiles.
On 30 April 2014, the Government Accountability Office issued a report stating that the system may not be operational any time soon because "its development was flawed". It said the GBI missile was at that point "capable of intercepting a simple threat in a limited way". On 12 August 2015, Lt. General David L. Mann characterized GMD as the nation's only ground-based defense against limited ICBM attacks.
Issues with the EKV prompted the MDA to work with Raytheon, Boeing, and Lockheed Martin on a new Redesigned Kill Vehicle, scheduled to debut in 2025. In 2019, the government issued a stop work order for the RKV after recent test results indicated that the current RKV plan is not viable. The government "initiated an analysis of alternative courses of action"; on 21 August the MDA cancelled the $5.8 billion contract for the RKV. This initiates new work on bids for the successor to the Exo-Atmospheric Kill Vehicle to 2025. The current GMD programs continue per plan, with up to 64 GBIs in the missile fields for 2019.

Program costs

Expenditures on the Ground-Based Midcourse Defense program were estimated to be US$30.7 billion by 2007. In 2013, it was estimated that the program would cost $40.926 billion from inception through fiscal year 2017; in 2013–17 spending was to total $4,457.8M, an average of $892M per year.

Flight tests

Intercept tests

After the FTG-11 test on 25 March 2019, 11 of the 20 hit-to-kill intercept tests have succeeded. No flight intercept tests from 2010 to 2013 were successful. In response the Pentagon asked for a budget increase and another test for the fielded program. The successful intercept FTG-15 was accomplished by an operational team of the 100th Missile Defense Brigade using their standard operating procedures without foreknowledge of the timing of the ICBM launch.
NamedateResultDescription
IFT-32 Oct 1999SuccessThis was an element test of the EKV that relied on a surrogate booster vehicle. Because the Inertial Measurement Unit malfunctioned, the EKV used a backup acquisition mode to acquire the target.
IFT-418 Jan 2000FailureThis was the first end-to-end system test, again relying on a surrogate booster vehicle. The test was designed to target a mock warhead, transmitting its location by GPS, and ignore a single large decoy balloon. The failure to intercept was traced to an obstructed cooling line on the EKV that disrupted the IR sensors' ability to cool down to their operating temperatures in time, leaving the EKV unable to detect its target.
IFT-58 Jul 2000FailureThis was the second end-to-end system test. The test was designed to target a mock warhead, transmitting its location by C-band, and ignore a single large decoy balloon. The failure to intercept occurred because the EKV did not separate from the boost vehicle due to an apparent failure of the 1553 data bus in the booster.
IFT-614 Jul 2001SuccessThis test repeated IFT-5. The prototype X-Band radar falsely reported a missed target but was confirmed by a satellite, jet, and ground stations.
IFT-73 Dec 2001SuccessThis test repeated IFT-6 except that the target booster used Orbital's Target Launch Vehicle instead of Lockheed Martin's Multi-Service Launch System.
IFT-815 Mar 2002SuccessThe test was designed to target a mock warhead, transmitting its location by C-band, and ignore both a large decoy balloon and two small decoy balloons.
IFT-914 Oct 2002SuccessTwice delayed from August, this was the first test to use the Aegis SPY-1 radar, although it was not used to achieve the intercept. After the classification of decoys since May 2002, no information is known on their details.
IFT-1011 Dec 2002FailureThe failure to intercept occurred because the EKV did not separate from the boost vehicle because a pin broke that should have activated a laser to release the boost vehicle's restraining units.
IFT-13C15 Dec 2004FailureDelayed several times from December 2003 due to bad circuitry, this test was designed to use the Orbital Sciences booster from Kwajalein to hit a target from Kodiak, Alaska. The target flew as planned but the booster failed to leave the ground. The failure was traced to a software problem on the 1553 communications data bus, which may be incapable of processing messages at a rate that is fast enough for the GMD system to work effectively.
IFT-1413 Feb 2005FailureThis test repeated IFT-13C, with a booster from Kwajalein designed to hit a target from Kodiak, Alaska. Again, the target flew as planned but the booster failed to leave the ground. The failure was traced to the arms that hold the interceptor up in the silo. When they failed to fully retract, the launch was automatically aborted.
FTG-021 Sep 2006SuccessThis test involved the first ground-based interceptor launched out of Vandenberg Air Force Base to intercept a "threat-representative" target from Kodiak, Alaska. This was the first time that operational radar was used to capture targeting information. Not officially an intercept test, this was originally designed to collect data on the phenomenology of the intercept and act as a radar certification test. No decoys were used.
FTG-0325 May 2007FailureWith the same setup as FTG-02, the test target flew off-course and an intercept did not occur.
FTG-03A28 Sep 2007SuccessThis test was scheduled in response to the failure of FTG-03, this time with a successful intercept.
FTG-055 Dec 2008SuccessThis test launched a threat-representative mock warhead from the Kodiak Launch Complex, Alaska followed by a Ground-Based Interceptor from Vandenberg AFB. All components performed as designed.
FTG-0631 Jan 2010FailureThis test was to be the first to assess both a CE-II EKV and a complex target scene and the first test to use a newly developed FTF LV-2 target. While the target missile and interceptor launched and performed nominally, the Sea Based X-Band Radar did not perform as expected, and an investigation will explain the failure to intercept.
FTG-06a15 Dec 2010FailureThis test was similar to FTG-06, over a distance of 4,200 miles. While the Sea Based X-Band radar and all sensors performed as planned, the test was unable to achieve the planned intercept of a ballistic missile target.
FTG-075 Jul 2013FailureThis intercept test used an improved CE-I EKV.
FTG-06b22 Jun 2014SuccessThis test is designed to demonstrate an intercept and meet the unmet objectives of FTG-06a.
FTG-1530 May 2017SuccessThe test involved the new CE-II Block-I version of the EKV, which executed a direct collision with the ICBM target.
FTG-1125 March 2019SuccessThis test used two interceptors, one to crash into a dummy target representing an incoming ICBM and another to use sensors to detect another ICBM or other countermeasures.

Non-intercept tests

Canceled tests

Throughout the program's history, multiple test flights have been canceled, including BV-4, IFT-11, -12, -13, -13A, -15, FTC-03, and, most recently, FTG-04.

Estimated effectiveness

The system has a "single shot probability of kill" of its interceptors calculated at 56%, with the total probability of intercepting a single target, if four interceptors are launched, at 97%. Each interceptor costs approximately $75 million.