By Kris Osborn, President, Warrior
(Washington, D.C.) Are Taiwan, Japan, South Korea and contested areas of the South China Sea all extremely vulnerable to a massive People’s Liberation Army hypersonic missile attack? Potentially, as the PLA is known to be testing a variety of credible and potentially quite effective hypersonic weapons such as its ship and air-launched YJ-21 missile which has been fired from a warship and carried on a PLA Air Force H-6K bomber.
The prospect of this kind of attack lends further credibility to the Pentagon’s often discussed “fait accompli” concept, a threat possibility in which the PRC would attempt to annex Taiwan so quickly that US and allied responses would be unable to respond. This concern, cited several times in the Pentagon’s annual China report, presents a compelling need to accelerate hypersonic defenses. An existing US-Japanese collaborative effort, described by the Pentagon several years ago, has been working to develop and fast-track a high-speed, next-generation “Glide Phase Interceptor” weapon able to counter Chinese hypersonic weapons.
There does appear to be progress, as an essay published by the Missile Defense Agency reports that efforts to refine the Preliminary Design, test, further develop and “build” the GPI are now surging into the next development phase with GPI-manufacturer Northrop Grumman.
“Today’s decision represents a turning point for hypersonic glide phase defense,” said Lt. Gen. Heath Collins, MDA Director. “
The MDA essay specified that the surge forward with GPI is based upon “ the GPI concept’s technology maturity, high fidelity model performance predictions, detailed technical maturation plans and industry-provided cost and schedule proposals.”
The reference to “high-fidelity model performance predictions” seems quite significant as it appears to pertain to computer simulations and digital modeling and testing of weapons performance parameters. The Air Force and MDA have thus far achieved success with an ability to use precise computer simulation modeling to replicate weapons performance. An essay from GPI-maker Northrop Grumman does in fact explain that digital engineering has been successfully used to accelerate development of the system’s critical technologies.
“Complete flight experiments ahead of schedule leveraging the company’s own flight-proven systems used digital engineering practices to connect the entire GPI program to accelerate design processes and develop interceptor capabilities faster and more efficiently,” Northrop’s essay on GPI explains.
This means digital engineering procedures can, as described by the MDA, succeed in replicating, assessing, analyzing and testing technologies fundamental to developing weapons systems. This would indicate that perhaps new simulations are showing great progress and future performance indications regarding the Glide Phase Interceptor. These are the likely reasons why Collins referred to these recent developments as a “turning point” in the development of the weapons system. A key advantage of digital engineering, senior Air Force weapons developers have explained, is that the performance of potential prototypes or design models can be accurately evaluated “before” bending metal. This technique proved extremely effective in the early development of the Sentinel ICBM program, as weapons developers were able evaluate as many as eight or nine designs before deciding which prototypes to build. This of course saved time, streamlined the developmental process and lowered costs.
In terms of practical or tactical impact, progress with GPI is quite significant as it could enable the US and Japan to essentially form a hypersonic defense envelope capable of defending across wide areas of the Pacific. The most significant element fundamental to the weapons ultimate operational success would likely pertain to “networking” capacity of the targeting systems used. Specifically, a hypersonic projectile is known to pass so quickly from one radar aperture or field of regard to another, that it can become nearly impossible to develop the kind of “continuous” target track necessary to intercept the hypersonic threat. In some cases this can be established through leveraging lower-altitude, high-throughput Medium and Low Earth Orbit satellites potentially in position to process and relay targeting data from one radar aperture to another. This kind of networked targeting is the kind of thing which would likely enable the GPI to succeed in tracking and destroying hypersonic weapons moving at 5-times the speed of sound. Northrop’s essay does make reference to “threat tracking seekers.”
“Northrop Grumman’s design includes advanced technologies, such as a seeker for threat tracking and hit-to-kill accuracy, a re-ignitable upper stage engine used for threat containment and a dual engagement mode to engage threats across a wide range of altitudes,” a Northrop essay says.
Aegis Radar GPI
Since both Japan and the US are Aegis Radar partners, perhaps Aegis Combat Systems could help connect targeting windows between US and Japanese warships and form a protective blanket against hypersonics throughout vital portions of the Pacific. Sure enough, Northrop’s essay on the GPI maturation specifies that indeed the GPI is being designed to launch from Aegis-capable warships, something which further lends itself to potential US-Japan target networking.
A US-Japan hypersonic weapons alignment could form a specific defensive response to a specific threat, given that many observers are quick to point out that the PLA could seek to leverage its potentially short-lived “window of advantage” with its hypersonic arsenal to keep defensive allied forces beyond attack range and essentially “deny” them an ability to defend a given area. This obviously refers to the much discussed A2/AD strategy to prevent combat access to vital areas with the threat of hypersonic attack. Should a credible hypersonic defense be operational, however, this equation changes and perhaps both the US and Japan could be positioned to defend Taiwan and other areas of the Pacific from being held at bay by a Chinese hypersonic attack.
“This effort is expected to lead to a follow-on development and production contract in support of achieving the Department of Defense priority requirement of developing integrated layered defeat capabilities to degrade adversaries’ hypersonic weapons,” the MDA essay says.
The GPI is intended to intercept a boost-glide weapon which fires up along the boundary of the earth’s atmosphere before using sheer speed of descent to destroy its intended target. Naturally this kind of defensive weapon incorporates new generations of high-speed tracking technology.
A hypersonic boost-glide weapon, for example, is thrust up into the atmosphere to glide at hypersonic speeds before descending upon its target at unparalleled speed. It is at this “glide” point in the missile’s trajectory where there is the best opportunity to intercept it, just prior to its turning down into its ultimate high-speed descent. Given this, there is a particular pressing need to quickly establish an effective hypersonic defensive response.
“So when you’re in the glide phase — which is higher up from the terminal, right, where a hypersonic vehicle is likely in its most vulnerable phase — that’s actually a pretty tough environment to be in. And you can’t take an air defense weapon and operate it there nor can you take a space weapon like an SM-3 and operate there, it’s just a different environment,” Navy Vice Adm. Jon Hill, former Director, Missile Defense Agency told reporters, according to a Pentagon transcript from as far back as 2022.
Earlier thinking from the MDA suggested that the GPI might not be ready until the early 2030s, however it is possible that rapid technological progress resulting from US-Japanese collaboration is accelerating this timeframe. A joint US-Japanese collaborative effort could speed up this process and offer land-basing opportunities for the weapon.
