US MDA performs first intercept test with selected stage booster upgra…

A ground-based interceptor was launched from Vandenberg Space Force Base, California, on 11 December. This was the first flight test of a three-stage booster operating in two-stage mode, meaning the third-stage was not ignited. (Missile Defense Agency)

The US Missile Defense Agency (MDA) conducted a test of the upgraded Ground-Based Interceptor (GBI), the first test of the capability to use the two-stage boost mode that is designed to intercept intercontinental ballistic missiles (ICBMs) across a wider engagement envelope, the agency announced on 11 December.

The two/three-stage selectable GBI was launched from Vandenberg Space Force Base, California, and intercepted an intermediate-range target that was launched from a C-17 over the Pacific Ocean, according to MDA spokesperson Heather Cavaliere. The test validated Ground-based Midcourse Defense's (GMD's) Capability Increment 6B configuration, according to a statement from lead system integrator Boeing.

The last test of the GBI was in 2021 when the MDA tested a version of the selectable stage interceptor with a mock-up Exoatmospheric Kill Vehicle (EKV).

The interceptor released the Capability Enhanced-II Block 1 EKV after completion of the second-stage burn rather than after the third-stage burn, Cavaliere told Janes on 11 December. An earlier release of the vehicle enabled an intercept closer to the GBI's point of launch, Cavaliere said. The MDA declined to say how much earlier in the flight time the intercept was made.

“Future upgrades to sensing and tracking capabilities when coupled with the selectable two/three-stage booster will provide the warfighter with a robust ability to assess the threat after initial engagement while retaining the time to engage again, if necessary,” she said.