The US Missile Defense Agency awarded
Boeing a $4 billion contract modification to Ground-based Midcourse Defense (GMD) and Development and Sustainment Contract (DSC). The modification will extend the DSC period from January 2018 to December 2023. The GMD
is designed specifically to counter long-range ballistic missiles threatening the US homeland. It uses a three-stage booster, giving the necessary “legs” to perform intercepts over great distances. This range gives GMD by far the greatest coverage area of any US missile defense system, defending all fifty states and Canada. The modification also includes the delivery of a new missile field with 20 silos and two extra silos in a previously constructed missile field at Fort Greely in Alaska. The Missile Defense Agency is also deferring the production of 20 additional Ground Based Interceptors (GBIs) due to the deal associated with not meeting the entrance criteria for the Redesigned Kill Vehicle (RKV) critical design review. GBIs are silo-launched and intercept ballistic missiles in their midcourse, while they are outside of the atmosphere and at their highest trajectory. The missile consists of a multi-stage rocket booster and a kinetic kill vehicle, which makes interception of ballistic missile warheads possible using hit-to-kill technology. The definitized part of the modification provides for technical capabilities to improve a state-of-the-art missile defense system in order of ensuring that defensive capabilities remain relevant and current. These efforts include Boost Vehicle (BV) development; providing GBI assets for labs and test events; development, integration, testing and deployment of ground systems software builds to address emerging threats; development and fielding of upgraded launch support equipment; expanded systems testing through all ground and flight testing; cyber security support and testing; and, operations and support via performance based logistics approach. Work will take place within the US.
The USA’s Ground-Based Midcourse Defense (GMD) program uses land-based missiles to intercept incoming ballistic missiles in the middle of their flight, outside the atmosphere. The missiles are currently based at 2 sites in the USA: 4 at Vandenberg AFB in California, and 20 (eventually 26) at Fort Greely in Alaska.
The well-known Patriot missiles provide what’s known as terminal-phase defense options, while longer-reach options like the land-based THAAD perform terminal or descent-phase interceptions. Even so, their sensors and flight ranges are best suited to defense against shorter range missiles launched from in-theater.
In contrast, GMD is designed to defend against intercontinental ballistic missiles (ICBMs). It depends on tracking that begins in the boost phase, in order to allow true mid-course interception attempts in space, before descent or terminal phase options like THAAD and then Patriot would be tried. In order to accomplish that task, GMD missiles must use data feeds from an assortment of long-range sensors, including satellites like SBIRS and DSP, some SPSS/BMEWS huge early-warning radars, and even the naval SBX radar.