Ground Based Interceptor (GBI)

The US "successfully intercepted" an intercontinental ballistic missile target waryead 30 May 2017. The Ground-Based Interceptor was launched from Vandenberg Air Force Base in California shortly after 3:30 PM ET. A little more than one hour later, the Pentagon confirmed that it had successfully collided with the target over the Pacific Ocean.

The US Defense Department conducted the missile defense system test as North Korea continued the development of intercontinental ballistic missiles capable of reaching the US mainland. The test occurred just days after the North Korean regime launched its ninth missile this year. The test involved launching a target meant to simulate an ICBM from a base in the Marshall Islands and then shooting it down with a ground-based interceptor launched from Vandenberg AFB in California.

The US government plans to strengthen its missile defense to protect the mainland by deploying additional 8 interceptors in Alaska, bringing the total to 44 nationwide by the end of 2017.

The ground-based missile interceptor has succeeded in only 9 of 17 attempts since 1999. The most recent test in 2014 was a success. Since the system was initially fielded in 2004, by 2016 the Missile Defense Agency had conducted nine tests pitting an interceptor against a target. The system destroyed its target in only three of them, despite the fact operators knew ahead of time when and where the target missile would be launched, its expected trajectory, and what it would look like to sensors. Regardless, the United States currently fields 26 interceptors at Fort Greely in Alaska and four at Vandenberg Air Force Base in California and plans to install 14 more at Fort Greely. In March 2013, the Secretary of Defense announced plans to increase the number of deployed GMD interceptors called Ground-based interceptors (GBI) from 30 to 44 by the end of 2017 to add protection to the homeland and to stay ahead of long-range ballistic missile threats. In 2016, DOT&E reported that GMD demonstrates a limited defense capability in part, because of the system’s low reliability and the continual discovery of new failure modes during testing.

There are two versions of interceptors that are currently fielded, the version with the initial kill vehicle, called Capability Enhancement (CE)-I, and the upgraded version, called CE-II. Both of these interceptor versions are paired with the first generation boost vehicle. The Missile Defense Agency (MDA) is currently developing a new interceptor version called CE-II Block I, consisting of new divert thrusters and an upgraded boost vehicle that addresses obsolescence issues and problems previously discovered during flight testing. In addition, MDA initiated the development of a Redesigned Kill Vehicle that is intended to address concerns about GMD’s fleet reliability. According to program officials, the Redesigned Kill Vehicles are not expected to begin fielding until 2022. During the test 22 June 2014, a long-range ground-based interceptor launched from Vandenberg Air Force Base, California, intercepted an intermediate-range ballistic missile target launched from the U.S. Army’s Reagan Test Site on Kwajalein Atoll in the Republic of the Marshall Islands. For this exercise, a threat-representative, intermediate-range ballistic missile target was launched from the Reagan Test Site. The U.S. Navy destroyer USS Hopper (DDG 70), with its Aegis Weapon System, detected and tracked the target using its onboard AN/SPY-1 radar, which provided data to the GMD fire control system via the Command, Control, Battle Management and Communication (C2BMC) system. The Sea-Based X-Band radar also tracked the target, and relayed information to the GMD fire control system to assist in the target engagement and collect test data.

About six minutes after target launch, the Ground-Based Interceptor was launched from Vandenberg Air Force Base. A three-stage booster rocket system propelled the interceptor’s Capability Enhancement II EKV into the target missile’s projected trajectory in space. The kill vehicle maneuvered to the target, performed discrimination, and intercepted the threat warhead with “hit to kill” technology.

Riki Ellison, Chairman and Founder of The Missile Defense Advocacy Alliance (MDAA), issued a statement June 19, 2014 concerning the FTG-06b CE-II Ground Based Interceptor test, planned for Sunday, June 22, 2014. Ellison countered recent claims that CE-II two test failures in 2010 were caused by rushed deployment in 2004, saying "The responsibility of the failures and lack of annual testing of the CE-IIs is not due to the rush to deployment in 2004. It is directly related to misguided leadership by the previous MDA director and the lack of investment from the President's budget into this system since 2008."

Ellison called out poor decisions such as canceling the Multiple Kill Vehicle program in 2009, crafting industry contracts to "incentivize cost cutting rather than increased reliability and confidence in the system." Mr. Ellison also pointed out the steep funding cuts from "$1.4 billion to $761 million towards the development and research of these interceptors" beginning in 2009. "These leadership decisions and lack of adequate funding over this time period impacted confidence, reliability, maintenance and modernization of the entire GBI fleet and the system as a whole." Mr. Ellison stated.

In regards to GBI testing, Ellison pointed out that "None of the GBI interceptor tests have ever been operationally realistic because they just fire one interceptor at one missile." He went on to say that "this system was never designed to be reliant on one shot; it operates by firing multiple interceptors at one missile thereby mathematically increasing confidence of reliability to intercept above 95 percent."

In response to critics to claim the GBI tests are unrealistic because they are scripted, Mr. Ellison said that "we clearly know where the North Korean launches start from, what their exact speeds and trajectories are to strike the United States and what the most likely warhead configuration and countermeasures on their missiles will be. Of course we should be conducting scripted tests against those exact specifics within the limitations of our test ranges over and over again. This is what increases confidence in the system protecting the nation."

Ellison concluded his statement by emphasizing the importance of the test, saying it will "define the future for GMD, its investment, and its leadership.... Our ground based missile defense system represents the very best of our technology, requires the very best engineering and is the only system our nation has to defeat long-range ballistic missiles."

"Even if Sunday's test is successful, it would demonstrate little about the kill vehicle's capability and reliability," said Dr. Laura Grego, a senior scientist at the Union of Concerned Scientists (UCS) - which opposes missile defense. "It would be the first time in three tries that it hit its target, but 33 percent is still a failing grade — and not a good argument for buying more." Grego noted that the MDA considered the previous CE-I kill vehicle successful after two successful intercepts, but that was before last year's failure, which led to the discovery of a number of design flaws, some which are common to both the CE-I and II. The flaws in the system are so serious that the Obama administration has directed the MDA to redesign the kill vehicle to replace both versions.

Grego noted that despite the fact that the CE-II kill vehicle has thus far failed its only two intercept tests, the Missile Defense Agency has already fielded it. Approximately a third of the 30 GMD interceptors at Vandenberg and Fort Greely in Alaska are armed with the CE-II. The rest of the interceptors are equipped with the CE-I, whose track record is also less than reassuring.

According to UCS, many of GMD system's problems are rooted in decisions made more than 10 years ago. In 2002, the Bush administration mandated the MDA to field a system by the fall of 2004 to defend the United States against a theoretical missile attack. To facilitate this deadline-driven approach, the Bush administration and Congress loosened or set aside the normal requirements and oversight processes for new weapons systems, which allowed the MDA to field technology under development that has not passed the rigorous milestones normally required. Consequently, the MDA fielded equipment with completely unknown capability. Over the last decade, the MDA has conducted far too few tests to establish the GMD system's effectiveness and reliability. Moreover, the tests the agency has conducted have been highly scripted and held under unrealistic conditions.

As of May 2014, the Department of Defense (DOD) had deployed 30 GMD interceptors and it planned to deploy 14 more by the end of fiscal year 2017. The GMD program has completed fielding 23 of the original GBI missiles with the Capability Enhancement I (CE-I) version of the exoatmospheric kill vehicle (EKV). The GMD program has also manufactured and delivered 13 of the GBI missile with the Capability Enhancement II (CE-II) version of the EKV, three of which have been used in flight tests. On March 15, 2013, the Secretary of Defense announced the U.S. will deploy 14 additional CE-II GBIs by fiscal year 2017, increasing the number of deployed GBIs from 30 to 44.

However, flight testing intended to demonstrate the system’s capabilities and limitations was not scheduled to be completed until at least 2022. MDA failed both of its attempts in 2010 to demonstrate the upgraded GMD interceptor, called Capability Enhancement (CE)-II, causing MDA to fall several years behind on deploying new interceptors. The second CE-II attempt to intercept a target missile, called Flight Test GMD (FTG)-06a, occurred in December 2010. According to the Director, MDA, the test failed because of excessive vibration in the inertial measurement unit—a component of the kill vehicle’s guidance system. As a result, MDA halted deliveries of the remaining CE-IIs until the failure is resolved. Interceptor production will restart on 14 more in-progress missiles if FTG-06b is successful, in keeping with MDA's fly-before-buy philosophy. Additionally, the cost to demonstrate, as well as fix, the already produced CE-IIs increased from $236 million to $1.309 billion.

On 5 July 2013, the Missile Defense Agency, the US Air Force's 30th Space Wing, the Joint Functional Component Command, Integrated Missile Defense (JFCC IMD), and US Northern Command (NORTHCOM) conducted an integrated exercise and flight test of the Ground-based Midcourse Defense (GMD) of the initial fielded version of the GMD interceptor, called CE-I, of the United State's Ballistic Missile Defense System. Although a primary objective was the intercept of a long-range ballistic missile target launched from the US Army's Reagan Test Site on Kwajalein Atoll, Republic of the Marshall Islands, an intercept was not achieved. The interceptor missile was launched from Vandenberg Air Force Base, California. Program officials were to conduct an extensive review to determine the cause or causes of any anomalies that might have prevented a successful intercept.

The July 2013 failure subsequently delayed FTG-06b to the third quarter of fiscal year 2014. 5MDA initially planned to conduct FTG-06b in the third quarter of fiscal year 2012 but the test was delayed to the second quarter of fiscal year 2014 because of challenges developing the FTG-06a mitigation. The July 2013 CE-I test has further delayed FTG-06b to third quarter of fiscal year 2014 in order to implement corrective actions based on an ongoing failure review of the CE-I test.

The Missile Defense Agency made progress on Ground-based Midcourse Defense (GMD) return-to-intercept during FY12. It redesigned and tested Exo-atmospheric Kill Vehicle (EKV) components and established more stringent component and manufacturing process requirements. Analysis and ground test results indicated the previous mission failure root causes had been identified and fixed, but a demonstration flight test was required to validate that conclusion. The MDA scheduled a 2-flight test series designed to validate these fixes. The GMD Control Test Vehicle-01 (GM CTV-01) had been scheduled for second quarter FY13 as an interceptor-only diagnostic flight test to further characterize kill vehicle behavior in a representative flight environment. The Flight Test GMD-06b (FTG-06b) had been scheduled for third quarter FY13 as a repeat of the FTG-06a flight test.

The test windows represented the latest in a series of incremental slips over FY12. At the beginning of FY12, GM CTV-01 was scheduled to be flown in the middle of third quarter FY12 and FTG-06b was scheduled for the middle of fourth quarter FY12. Major causes of the slips were additional analysis time needed by the Failure Review Board, developmental issues with new inertial measurement unit firmware and isolation cradle hardware, and component manufacturing and quality concerns.

The Missile Defense Agency (MDA) successfully completed a flight test of a three-stage Ground-Based Interceptor (GBI), launched from Vandenberg Air Force Base, Calif., at 2 p.m. (PST) January 26, 2013. A target missile launch was not planned for this flight test. After performing fly out maneuvers, the three-stage booster deployed the Exoatmospheric Kill Vehicle to a designated point in space. Data from this flight test will be used to evaluate the Exoatmospheric Kill Vehicle system performance in a flight environment. If a target missile were present, the Exoatmospheric Kill Vehicle would collide directly with the threat warhead to perform a hit-to-kill intercept. Engineering data from this test will be used to improve confidence for future intercept missions.After separating from the booster, the Exoatmospheric Kill Vehicle executed a variety of pre-planned maneuvers to collect performance data in space. Initial indications are that all components performed as designed. Program officials will assess and evaluate system performance based upon telemetry and other data obtained during the test. This event, designated Ground-Based Midcourse Defense Control Test Vehicle (GM CTV)-01, was part of an extensive test series initiated after the Flight Test Ground-Based Interceptor (FTG)-06a failure in December 2010. The Exoatmospheric Kill Vehicle flown during GM CTV-01 was modified based on findings from the FTG-06a Failure Review Board. This test was the critical first step in returning GMD to successful intercept testing.

The Ground Based Interceptor [GBI] is the weapon of the National Missile Defense (NMD) system. Its mission is to intercept incoming ballistic missile warheads outside the earth's atmosphere (exo-atmospheric) and destroy them by force of the impact. During flight, the GBI receives information from the NMD Battle Management, Command, Control, and Communications (BMC3) to update the location of the incoming ballistic missile, enabling the GBI onboard sensor systemto identify and home in on the target. The GBI would consist of a multi-stage solid propellant booster and an exoatmospheric kill vehicle. No nuclear weapons would be used as part of the NMD system.

The Ground Based Interceptor will have an acceleration profile and burnout velocity that maximize the interceptor's reach, consistent with the long-range capability of the supporting sensors. The GBI payload will be an Exo-Atmospheric Kill Vehicle (EKV) equipped with a high-sensitivity infrared seeker and an agile divert system to support endgame intercepts of responsive threats at very high closing velocities. In addition, the payload will be hardened to elevated doses of X-rays to allow operation in nuclear environments. To limit the adverse effects of this environment on the interceptor, the defense battle management will distribute the engagements within the available battlespace; the larger the battlespace, the wider the separation, and the weaker the deleterious effects of a nuclear environment. Also, to achieve high confidence of success against all threat objects, salvos of interceptors may be launched against each credible threat object. These salvos will be spaced in time to reduce the likelihood of correlated errors among the intercept attempts.

The GBI seeker is expected to be able to do discrimination against initial simple threat countermeasure and penetration aid, though it would require assistance from ground-based radars or space-based sensors to address more complex and sophisticated targets.

The deployed GBI would be a dormant missile that would remain in the underground launch silo until launch. Launches would occur only in defense of the United States from a ballistic missile attack. There would be no flight testing of themissiles at the NMD deployment site. The technical status of each missile would be monitored and any required maintenance conducted at a contractor's offsite production facility. Interceptors in storage would be used to replace missiles requiring repair or selectively removed for reliability testing.

Each missile would contain approximately 12,595 kilograms (27,766 pounds) of solid propellant. The exoatmospheric kill vehicle would contain approximately 9 to 14 kilograms (20 to 30 pounds) of liquid propellant. These liquid propellants would consist of monomethylhydrazine and nitrogen tetroxide.

The GBI site would contain launch stations (silos), Interceptor Receiving and Processing Building, Interceptor Storage Facilities, and additional support facilities. Approximately 243 hectares (600 acres) would be required to support the GBI missile field and associated technical facilities. When the GBI site and associated technical facilities become fully operational, total site related employment would be approximately 150 to 200 personnel. Explosive Safety Quantity-Distance (ESQD) criteria would be used to establish safe distances from explosive hazard areas, such as solid propellants, to nonrelated facilities and roadways. These regulations are established by the Department of Defense. For the GBI silos, there would be a minimum 380-meter (1,250-foot) ESQD from inhabited buildings. In addition, the Interceptor Receiving and Processing Building and the Interceptor Storage Facilities would also have a 380-meter (1,250-foot) ESQD from inhabited buildings.

The interceptor, consisting of the solid propellant booster and exoatmospheric kill vehicle, would be shipped to the site in specially designed canisters using commercial carriers or government transportation. All shipping would be conducted in accordance with Department of Transportation regulations. Presently, there are no plans to store liquid propellants on-site. A small quantity of liquid propellants would be used by the exoatmospheric kill vehicle. The interceptor would arrive at the GBI site with the liquid propellants loaded and sealed inside the exoatmospheric kill vehicle. Additionally, the interceptor would be contained within a canister. Upon receipt, the canisterized interceptor would be monitored to inform workers if a leak had occurred during shipping. If a leak has occurred, a specially trained hazardous material response team and equipment would be used to remove any propellant from the canister. The propellant would then be contained and treated, as required. The Department of Defense and other government agencies have a long history of working with the solid and liquid propellants proposed for the GBI element and have developed standard operating procedures for the safe handling of these materials.

During normal daily operations, the only air and noise emissions would be associated with the electrical generators required to provide power to the site. These generators would only be required as backup power sources if commercial power to the site failed or if required to support a mission. At sites where no commercial power is available, or where the reliability of commercial power does not meet NMD system requirements, the generators would operate continuously.

To ensure an accidental launch of a GBI does not occur, the system would have a human in control at all times in addition to software and hardware safety systems. Additionally, stringent Department of Defense operating procedures, which prevent the launch by any one person, would be followed.

By 2007 the configuration of the GMD interceptor continued to struggle with an anomaly that had occurred in each of the element's flight tests. The anomaly had not yet prevented the program from achieving its primary test objectives, but neither its source nor a solution had been clearly identified or defined. The reliability of some GMD interceptors remained uncertain as well because inadequate mission assurance/quality control procedures may have allowed less reliable or inappropriate parts to be incorporated into the manufacturing process. Program officials planned to introduce new parts into the manufacturing process, but not until interceptor 18. MDA also planned to retrofit the previous 17 interceptors, but not until fiscal year 2009.

On 15 March 2013, US Secretary of Defense Hagel announced the US would strengthen homeland missile defense by deploying 14 additional Ground-Based Interceptors (GBIs) at Fort Greely, Alaska. This deployment would increase the number of deployed GBIs from 30 to 44, including the 4 GBIs at Vandenberg Air Force Base in California. These additional GBIs would provide a nearly 50 percent increase in the US missile defense capability.

In addition, as directed by Congress, the Department of Defense was conducting Environmental Impact Studies for a potential additional GBI site in the United States. While the Obama Administration had not made any decision on whether to proceed with an additional site at that time, conducting Environmental Impact Studies would shorten the timeline for construction if that decision was to be made. Also, due to cuts in congressional funding deployment of the SM-3 Block IIB missile had been delayed and resources would be shifted to fund the additional GBIs, as well as advanced kill vehicle technology that would improve the performance of the GBI and other versions of the SM-3 interceptor, adding protection against missiles from Iran sooner while also providing additional protection against the North Korean threat.

An 08 September 2014 report [DODIG-2014-111] by the DOD Inspector General found that Boeing Defense, Space and Security of St. Louis and Raytheon Missile Systems of Tucson, Arizona were not ensuring that software development processes and testing were sufficient, which could result in reliability issues. Boeing and Raytheon did not ensure all quality assurance and technical requirements for mission-critical assemblies flowed down to the supply chain and were verified. Therefore, it is uncertain that all supplier products will meet system, performance, and reliability requirements.

In November 2014 Boeing and Raytheon said they had corrected software and other quality assurance issues with a critical Exoatmospheric Kill Vehicle (EKV) that were identified in the September report by the Defense Department’s internal investigative arm.

Sources and Resources

• FY98 PEDS 0603871C National Missile Defense
• GBI/EKV Ground Based Interceptor/Exoatmospheric Kill Vehicle. Ground Based Interceptor (GBI) / Exoatmospheric Kill Vehicle (EKV) Hughes Missile Systems Company.