Ground-Based Midcourse Defense


Ground-Based Midcourse Defense, previously National Missile Defense, is an anti-ballistic missile system implemented by the United States of America for defense against ballistic missiles, 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.
As of 2018, the system is composed of two interceptor staging bases in the states of Alaska and California, with 40 staged in the former, 4 staged in the latter, for a total of 44 interceptors, as well as the component early warning and targeting sensors based on land, sea, and in orbit. As of 2019, a Missile Defense Review has requested 20 additional interceptors to be based in Fort Greely, Alaska, though their delivery has not materialized.
GMD is administered by the U.S. Missile Defense Agency, while operational control is provided by the U.S. Army, with support functions provided by the U.S. Air Force and U.S. Space Force.

Background

GMD after its renaming in 2002 remains a limited defense system, intended to protect the continental United States from limited launches of ballistic missiles. Examples given in the past have included countries such as North Korea.
GMD has undergone some controversy over its operational lifetime, such as with a study in 2000 by the Union of Concerned Scientists and the Security Studies Program at the Massachusetts Institute of Technology concluding that "ny country capable of deploying a long-range missile would also be able to deploy countermeasures that would defeat the planned NMD system." Countermeasures studied in detail were bomblets containing biological or chemical agents, aluminized balloons to serve as decoys and to disguise warheads, and cooling warheads to reduce the kill vehicle's ability to detect them. Currently, the Union of Concerned Scientists maintains that GMD is "unproven, unaccountable, and unhelpful for reducing the nuclear threat."
More recently, questions have been asked about the Pentagon characterizing the January 28 test in 2016 as a success, when LA Times reported that the EKV suffered a fault in its reaction control system thrusters, which resulted in "a distance 20 times greater than what was expected" according to an anonymous Pentagon scientist.
Under the Missile Defense Agency, GMD has conducted multiple test exercises, with mixed results. Early testing revealed deficiencies in the Ground Based Interceptor missile, as well as the Exoatmospheric Kill Vehicle. However, with time, success rates increased, marred by the occasional technical failure such as in 2010's FTG-06 where the Sea-based X Band Radar failed to perform as expected, and the subsequent FTG-06a where despite all elements performing correctly, intercept failed to occur.

Description

GMD is tied into existing United States missile warning infrastructure, as well as purpose-built radar sites. It also encompasses 44 ground-based missile interceptors housed at two military bases.
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 Space Force Base, California. A third site was planned for a proposed US missile defense complex in Poland, but was canceled in September 2009.
In late 2013, there were plans for a proposed Eastern United States site to house a battery of these missiles. Four sites were shortlisted in January 2014 for an East Coast site - SERE Remote Training Site in Maine, Fort Drum in New York, Camp James A. Garfield in Ohio, and Fort Custer Training Center in Michigan. Camp Ethan Allen Training Site in Vermont was dropped from consideration in late 2013.
In January 2014 the Pentagon announced they were starting a two-year environmental impact study under the 2013 defense authorization bill, which required two missile-defense sites to be identified on the East Coast. The CBO has estimated that a site would cost US$3.5bn.
In June 2019, Fort Drum in New York was chosen as the location for the potential East Coast missile defense site.
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.
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 $4.46 billion, an average of $892 million per year.

Flight tests

Intercept tests

After the FTG-12 test on 11 December 2023, 12 of the 21 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. Although they knew in advance that there would be a test launch, they did not know exactly when it would occur or its exact nature.
NamedateResultDescription
IFT-32 Oct 1999This 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 2000This 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 2000This 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 2001This 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 2001This 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 2002The 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 2002Twice 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 2002The 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 2004Delayed 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 2005This 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 2006This test involved the first ground-based interceptor launched from 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 2007With the same setup as FTG-02, the test target flew off-course and an intercept did not occur.
FTG-03A28 Sep 2007This test was scheduled in response to the failure of FTG-03, this time with a successful intercept.
FTG-055 Dec 2008This test launched a threat-representative mock warhead from Kodiak Launch Complex, Alaska followed by a Ground-Based Interceptor from Vandenberg AFB. All components performed as designed.
FTG-0631 Jan 2010This 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 2010This 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 2013This intercept test used an improved CE-I EKV.
FTG-06b22 Jun 2014This test is designed to demonstrate an intercept and meet the unmet objectives of FTG-06a.
FTG-1530 May 2017The test involved the new CE-II Block-I version of the EKV, which executed a direct collision with the ICBM target.
FTG-1125 Mar 2019This 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.
FTG-1211 Dec 2023This test used a CE-II EKV and was the first test of a three-stage GBI operating in a two-stage mode—releasing its kill vehicle earlier by not igniting the GBI's third stage. It was launched from Vandenberg Space Force Base and successfully intercepted an IRBM deployed from a C-17 aircraft over the Pacific Ocean.