Missile threats are proliferating. Here’s how the Pentagon is trying to keep up

As missile threats proliferate, the Missile Defense Agency is looking to new sensors, new digital tools—and new tweaks to older interceptors.

For example, a recent booster-rocket adjustment promises to increase the effectiveness of the Ground-Based Interceptor, or GBI, MDA director Lt. Gen. Heath Collins said at a CSIS event on Thursday. 

The GBI is a defense against intercontinental ballistic missiles, but a very limited one, with just 40 interceptors in Alaska and four in California. Its concept of operations has been described as “shooting a bullet with a bullet,” and in tests, they’ve worked a bit better than a coin toss. A Pentagon effort to improve their accuracy with an elaborate multi-warhead programs called the Redesigned Kill Vehicle was canceled in 2019 as too challenging and costly.

But in December, MDA personnel at Vandenberg Air Force Base in California found a relatively simple way to improve GBI performance, Collins said.

“We demonstrated two capabilities, and one was the three-stage/two-stage selectable launch, which was a new capability that was brought to bear. GBI was designed with three stages and every GBI today uses all three stages. The kill vehicle cannot separate until all the stages are burned and so you've got to wait for three stages to burn before you can separate to then close an intercept.” 

But a careful analysis determined that if they simply delayed the time between the second and third stage launch, “we actually picked up minutes of additional intercept space, decision space, to get maybe some previously uninterceptable scenarios,” he said.

Collins said that bringing modern digital and information tools into the agency will help find further performance improvements. 

A key question is whether such quick, cheap workarounds can rise to meet new missile challenges, such as Russian leader Vladimir Putin’s threat on Thursday to supply long-range strike weapons to proxy forces to attack Western targets. Russia has touted its new highly-maneuverable hypersonic missiles as “invincible,” though they have proven vulnerable to Patriot interceptors in Ukraine, and may be so to SM-6 missiles as well.

The Pentagon is years into a plan to field constellations of low-Earth satellites to better track new hypersonics as they maneuver. From the MDA side, Collins said, the arrival of new space and launch companies is also creating a new business in hypersonic vehicles that can be used as target practice. 

“Some of the near-term work is actually looking at hypersonic targets, because as we get an interceptor, we need to target,” he said.

If MDA can work with small, innovative teams and small businesses to “get them to the point where they're delivering capability that meets what we need in that intersection, that is going to be very powerful for us because…we can test more, and that is going to to only help us in the long run,” he said.

Collins didn’t directly address one newer airborne threat to U.S. forces: fast, advanced drones that sometimes blur the line between a robot and a missile. But he did point out that the Iranian attack on Israel in April, which employed hundreds of missiles alongside strike drones was “larger than we've seen, ever. And it just forecasts more to come.”

Defense against large drone swarms is more likely to fall to the forces on the ground, possibly outfitted with capabilities provided by MDA.

Earlier this week, the head of U.S. Army Futures Command said that the problem of drone swarms in the future might not look as difficult as it does on today’s Ukraine battlefield. The United States will have a much bigger and more coordinated force to confront the problem, Gen. James Rainy said at a CSIS event on Monday. 

“I'm a little more optimistic because what you're not seeing is anybody execute joint combined arms maneuver, right? So if somebody was flying [unmanned aerial systems] at us, we would fight the UAS. But we would also be fighting wherever they came from, plus their maneuver force, plus bringing the joint force to bear, so I'm a little more optimistic. It's hard to drop the quadcopter grenade into the turret of an M1 tank when it's coming at you 70 kilometers an hour, with a couple hundred of its friends, and you're on fire. You know, it's just hard.”