An enemy intercontinental ballistic missile (ICBM) shooting through space as part of a massive nuclear attack can be very difficult for missile defenses to intercept, due to the sheer amount of debris, clutter and specific enemy countermeasures such as decoys intended to confuse or throw off sensors guiding interceptor “kill vehicles.” 

Several ICBMs can present even more of a problem for defenses, as seekers can at times be at a loss to track multiple threats simultaneously. Moreover, and to perhaps an even greater degree, defenses struggle to distinguish an actual warhead-carrying ICBM from a decoy, debris or even non-lethal parts of the missile breaking off in-flight to release a reentry vehicle. 

The complexity of these challenges, and the concerning pace at which adversaries continue to develop new weapons and countermeasures, provides much of the inspiration for a massive Pentagon and Missile Defense Agency effort to engineer newer, more advanced radar systems, interceptors and sensors. 

For example, the MDA is already progressing with a new Next-Generation Interceptor intended to help bring missile defense into a new era of sophistication and, among other things, potentially engineer multiple-kill vehicle interceptors able to target and “take out” several attacking ICBMs at once, essentially knocking them out of the sky. While early in its development, the NGI program is exploring options for interceptor systems able to operate several “kill vehicles” from a single interceptor. The effectiveness of this mission rests in large measure upon the technical precision and sophistication of sensors and seekers able to successfully discern actual warhead targets amid the clutter. 

The Missile Defense Agency is also bringing this mission to new levels of sophistication by finalizing preparation of a new generation of ultra long-range, high-powered sensitive radar technology able to network with Ground Based Interceptors and introduce new levels of target discrimination. Its called Long Range Discrimination Radar (LRDR), a system an MDA essay says can “search, track and discriminate ballistic missiles, threats as small as baseball sized objects and even hypersonic weapons” through a 220-degree wide field of view. 

The emerging radar, slated to reach operational capacity this year, is a solid state radar engineered with advanced missile defense algorithms which can provide track data and discrimination data to GBIs. The tactical concept, a senior Pentagon weapons developer explained to The National Interest, is to enable a “first-shot kill” whenever possible.

“It is designed with proven radar technologies and proven ballistic missile defense algorithms. The radar has been designed for future upgrades to make it better as we go. We can update the LRDR with new software as new threats emerge,” the senior official said. 

The MDA essay explains that the S-band radar “can be scaled and extended to adapt to new threat sets, like hypersonic threats, without changing the hardware design.” 

Discerning the actual warhead, or emerging reentry vehicle from other objects presents significant complexities for seekers looking to pinpoint the target correctly, and highly sensitive and discriminating systems such as the LRDR are engineered to address this. The Pentagon official described that the LRDR can “steer” the GBI interceptor into the warhead after identifying the warhead itself as separate and distinct from other non-lethal parts of an ICBM such as its outer shell which merely transports the warhead. 

“Where do I need to steer my interceptor? You want to hit the re-entry vehicle and you need precise radar,” the official added. 

As an ICBM approaches descent, it “comes apart in space,” the official described, explaining that many objects can be “floating and flying along at 10,000 miles per hour close to the reentry vehicle.” The reentry vehicle of course includes the lethal nuclear warhead and, as the official described it, the “other stuff burns up in the atmosphere.” 

Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.

Image: Reuters.