MDA demonstrates selectable stage booster for GBI

A long-range Ground-Based Interceptor (GBI) is launched from Vandenberg Air Force Base, California, on 12 September. This was the first flight test of a GBI three-stage booster operating in two-stage mode. (Missile Defense Agency)

The US Missile Defense Agency (MDA), in association with Boeing and Raytheon Technologies, on 12 September conducted a test launch of a Ground-Based Midcourse Defense (GMD) Ground-Based Interceptor (GBI), flying a mock-up of the Exoatmospheric Kill Vehicle (EKV), with a three-stage booster operating in a two-stage mode.

The milestone test – in which the third stage was not ignited – demonstrates a new capability for the GBI, allowing it to release the EKV earlier in flight and, accordingly, enable an earlier opportunity to intercept and defeat a missile threat. The MDA designates this new capability as “a 2-/3-Stage selectable GBI”.

During the test, a GBI containing a Raytheon-designed mock-up of the EKV's mass launched into space and demonstrated proper and safe kill vehicle ejection. According to Raytheon, using a mock-up of an EKV provided a substantial reduction in the cost of the test, while still allowing engineers to gather data for EKV during booster flyout. It also spared critical defence assets that were not required in the non-intercept test.

Made possible through digital system modelling software upgrades, the new 2-/3-Stage selectable GBI capability gives operators the real-time choice between a two-stage or three-stage interceptor, depending on the threat's location and speed. The stage mode determines when the kill vehicle is released from the GBI. “This achievement will allow GBIs to be modernised and fielded with this critical capability as a part of the MDA's Service Life Extension Program,” Boeing said in a statement.