Kinetic Energy Interceptor (KEI)

Originated From:United States
Possessed By:United States
In Service:Terminated

The Kinetic Energy Interceptor (KEI), as originally envisioned, would have provided land-based and sea-based defense against medium and long-range ballistic missiles in all phases of flight.

KEI was originally conceived to provide boost-phase defense, or the ability to destroy enemy missiles just after they have been launched. In the boost phase, ballistic missiles are slow and vulnerable, their location is predictable, and countermeasures and decoys cannot be deployed. However, the Missile Defense Agency (MDA) later changed the concept to include not only the boost phase, but also the mid-course and terminal phases.

The system was planned to include (1) land-based interceptors mounted on mobile launchers, transportable by aircraft, and capable of deployment along the borders of threatening nations, and eventually to expand to (2) sea-based interceptors mounted on Navy destroyers and cruisers, possibly as part of the Aegis Ship-Based BMD. Once operational, KEI would have been able to engage a medium or long-range ballistic missiles within the first five minutes of its flight.

Patriot-like mobile launchers were to be used to transport the land-based interceptors. Each launcher would carry two interceptors housed in separate canisters, and would be transportable via a C-17 transport aircraft. It takes approximately three hours to set up a KEI battery of 10 missiles and 5 mobile launchers.

A command and control battle management and communications (C2BMC) component, consisting of six humvees, would integrate the KEI with the rest of the Ballistic Missile Defense System. Since KEI does not have its own radar or sensors, C2BMC was to rely on systems deployed by other BMD programs such as the Aegis AN/SPY-1 radar system, the Space Tracking and Surveillance System (STSS), or the Sea-Based X-Band Radar (SBX).

Once a threat has been detected, KEI launches its high-velocity interceptor missile (36 feet long and 36 inches wide), which will fly toward its target at two-and-a-half to three times the speed of the average tactical missile, thus making KEI the fastest of its kind. The first and second stages of the booster burn together in 60 seconds, propelling the interceptor forward at a velocity of 6 kilometers per second.

During the third phase, the interceptor adjusts its trajectory and eject its “kill vehicle,” a small weapon that will incorporate elements from two other MDA defense projects: the Exoatmospheric Kill Vehicle (EKV), a device that is used to destroy enemy missiles outside the atmosphere; and the Standard Missile-3, a sea-based missile with a kinetic warhead. The kill vehicle will close in on its target, aim for the missile’s brilliant plume, and slam into the enemy warhead, completely destroying the threat.

Although the project was moving forward for some time, KEI became the subject of much controversy and doubt. Many believed that the project was too risky, might not work as planned, and diverted attention and resources from more promising programs.  KEI was to cost an estimated $22 billion over 10 years.

Others pointed out that MDA’s decision to shift KEI from a boost-phase to an all-encompassing defense system simply defied logic, since KEI would have replaced two brand new rockets that were developed at considerable expense. Another problem that many pointed out is the fact that the 36-foot long KEI interceptor missile does not fit on the Navy’s Aegis cruisers and destroyers, thus hampering the feasibility of relatively inexpensive sea-based deployment.

In December 2003, MDA awarded an initial $4.5 billion contract to a Northrop Grumman-led team including Raytheon, Orbital Sciences, Aerojet, and ATK. Until recently, the project was in the development and testing phase. Between 2003 and 2011, the team was scheduled to produce 10 land-based interceptors and conduct 5 integrated flight tests, with deployment scheduled for sometime between 2010 and 2012.

The Kinetic Energy Interceptor was de-funded by the Obama administration on recommendation from Secretary of Defense Gates. The cut was part of the $1.4 billion trimming of the missile-defense budget for 2009.




“U.S. Kills Northrop Grumman missile-defense program,” Reuters, 11 June 2009.
Center for Security Policy.
Hackett, James T. “Missile Defense Going Astray?” The Washington Times, 29 April 2004.
“KEI Contractors Borrow From Other MDA Programs to Meet Schedule.” Inside Missile Defense, 28 April 2004.
Missile Defense Agency.
Northrop Grumman Corporation, KEI Introduction.
Northrop Grumman Corporation, KEI Fact Sheet.
Northrop Grumman Corporation, KEI Frequently Asked Questions.
“Northrop Grumman And Raytheon Bid For Kinetic Energy Interceptor.” Space Daily, 7 March 2003.
Raytheon Company.

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