A Ground-based Interceptor missile launched from North Vandenberg today at 10:30 a.m. Pacific Time Sept. 12. (U.S. Space Force/Airman Kadielle Shaw)

WASHINGTON: The US successfully tested a new capability for its Ground Based Interceptor (GBI) missile defense system over the weekend, with a top US official declaring the system worked “exactly” as it was designed.

The test, which occurred around 10:30 AM PST on Sept. 12, involved the GBI flying with a mock-up of a three-stage booster for the Exoatmospheric Kill Vehicle (EKV), the part of a missile interceptor that actually destroys the incoming ballistic missile. The test featured only two of the stages, as opposed to all three which can be used to launch the EKV into position, according to the Missile Defense Agency.

Using only two of the three stages represents a new capability, which MDA is calling the “2-/3-Stage selectable GBI,” that will allow earlier release of the EKV if needed to more accurately target an incoming weapon.

“This capability gives the warfighter greater flexibility in executing the defense of the homeland while significantly increasing the battlespace for successful threat engagement,” MDA stated. “Using a mock-up of an EKV provided a significant reduction in cost of the test and spared critical defense assets that were not required in this non-intercept test.”

Vice Adm. Jon Hill, the head of the MDA, said in the statement that “the system worked exactly as it was designed” to operate. He also noted that the improvement on GBI flexibility from this new capability should help fill the gap until its replacement, known as the Next-Generation Interceptor (NGI), comes online.

Tom Karako, a missile defense expert with the Center for Strategic and International Studies, described the system this way: “Think of it as just telling the third stage not to fire, which allows the kill vehicle to open its eyes, unbuckle its seatbelt, and get to work that much sooner. It trades the speed that the third stage would add for time. And that translates to flexibility.”

The timing of test could raise eyebrows, as it occurred shortly after North Korea declared a successful test of a new long-range cruise missile. But Karako shot down any notion that the two launches were directly linked to each other. After all, a GBI test launch takes significant planning to arrange and organize.

“This long-planned and important milestone will go towards ensuring that GMD continues to improve and adapt to increasingly complex ICBM threats from the likes of North Korea,” he said.

But, Karako noted, the fact Pyongyang launched a cruise missile as opposed to a ballistic missile should be good reason for “some in the missile defense community to wake up and smell the coffee” about the need to advance homeland defense capabilities.

“The old conversation organized around rogue state ballistic missiles is stuck in the 1990s. The neat little boxes are all blurring together,” Karako said. “We have to contend with the full air and missile threat spectrum from mud to space, across all aspects — from UASs to cruise missiles, from ballistics to gliders, and more. The specter of imaginative, complex, and integrated attack from across this spectrum is a central component of military challenges to US power projection and homeland defense alike.”