DARPA Starts Work On “Glide Breaker” Hypersonic Weapons Defense Project

The program’s main goal is to find ways to make America’s enemies think twice before using hypersonic weapons.

byJoseph Trevithick|
Air-Launched Hypersonic Missiles photo


As the threat of hypersonic weapons

continues to grow, one of the Pentagon’s top research and development arm is moving ahead with a new project to explore ways to guard against them. The Defense Advanced Research Projects Agency’s Glide Breaker project will look into various “component technologies” needed for one or more defense systems, but will focus heavily on a hard-kill interceptor to knock the fast-flying weapons out of the sky.

DARPA showed off concept art of the interceptor portion of Glide Breaker for the first time at its D60 Symposium, which honors the organization’s 60th anniversary, in September 2018. The agency’s Tactical Technology Office had previously hosted a gathering to explain the project and its requirements to interested parties in July 2018.

“The objective of the Glide Breaker program is to further the capability of the United States to defend against supersonic and the entire class of hypersonic threats,” DARPA said in an announcement for the July 2018 “Proposers Day.” “Of particular interest are component technologies that radically reduce risk for development and integration of an operational, hard-kill system.”

So far, there are few other publicly available details about the program. In its budget request for the 2019 Fiscal Year, DARPA did not ask for any money for Glide Breaker specifically or for research and development of hypersonic defense systems broadly.

It’s also not clear how Glide Breaker may be related to the Missile Defense Agency’s (MDA) own hypersonic defense project, which you can read about in more detail here and also includes plans for some sort of anti-hypersonic missile weapon system. As of February 2018, MDA expected to spend more than $700 million in total on that research and development project through at least 2023.

DARPA’s concept art also shows hard-kill, kinetic interceptors about to destroy unpowered, hypersonic boost-glide vehicles, which would fit with the program’s name. However, the project’s stated goal of researching and developing technologies to defeat both high-supersonic and hypersonic threats suggests that such a system would only be one element of the research into a set of layered defenses that would work against both boost glide-type and air-breathing weapons.

In addition, “breaker” is a clear call back to at least two earlier DARPA efforts, Assault Breaker and Tank Breaker, both of which were Cold War-era projects focused on defeating Soviet tanks and other armored vehicles. The former program also featured a multi-faceted approach that led to the development of a host of air and ground-based sensors, weapon systems, and other technologies.

Assault Breaker included work on what would become the E-8C Joint Surveillance Target Attack Radar System (JSTARS) battlefield management command and control aircraft and the RQ-4 Global Hawk drone, as well as the Battlefield Surveillance Aircraft-Experimental (BSAX) program, which employed Northrop's Tacit Blue stealth demonstrator as a low-observable sensor platform. It also helped drive the development of Northrop Grumman’s Brilliant Anti-armor Tank (BAT) submunition and the U.S. Army’s Army Tactical Missile System (ATACMS) quasi-ballistic missile. BAT has since evolved into the GBU-44/B Viper Strike glide bomb.

Research under DARPA's Assault Breaker program into long-range, stand-off sensors to spot Soviet armored formations and battle management capabilities to help friendly forces to engage them helped lead to the E-8C Joint Surveillance Target Attack Radar System aircraft, one of which is seen here., USAF

It seems likely that DARPA will pursue a similar 'ecosystem approach' with Glide Breaker. The U.S. military’s existing combination of terrestrial and space-based early warning sensors are simply not capable of reliably tracking strategic hypersonic weapons and none of its fielded or in-development missile defense weapons have the capability to engage these threats. American forces on the ground and at sea also have limited means of spotting a hypersonic weapon strike and no way of stopping it.

On the strategic side, senior U.S. military officials, including Michael Griffin, the Undersecretary of Defense for Research and Engineering, and U.S. Air Force General John Hyten, head of U.S. Strategic Command, have both been particularly strong advocates for expanding and improving space-based sensor networks and deploying space-based anti-missile systems. Hyten has been particularly vocal about ensuring that space-based sensors can track hypersonic weapons, which isn’t surprising given the significant investments that Russia and China are making in nuclear-capable hypersonic boost-glide vehicles.

The video below offers the best available look at Russia's ballistic missile-launched, nuclear-capable Avangard hypersonic boost-glide vehicle, as well as computer-generated imagery showing how it would operate in flight.

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There has been less discussion of how to counter the growing threat of hypersonic weapons to conventional ground and naval forces, but those concerns are very real, too. The Russians have begun fielding the Kh-47M2 Kinzhal, an air-launched version of their Iskander quasi-ballistic missile, which can reach hypersonic speeds. China is in the process of developing an air-breathing hypersonic weapon that it could potentially use in a surface-to-surface or air-to-surface role.

In both strategic and tactical settings, hypersonic weapons look set to offer a game-changing ability to launch virtually no-notice strikes against time-sensitive and other high priority targets. Their speed and ability to maneuver give them the ability to break through or simply dodge existing missile defenses.

The video below shows a test of China's Starry Sky 2 air-breathing hypersonic vehicle in August 2018.

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Glide Breaker’s core objective seems to be to find a way to challenge these inherent capabilities and make it clear to any potential opponent that a hypersonic weapon strike is in no way guaranteed to succeed against American forces. “A key figure of merit is deterrence: the ability to create large uncertainty for the adversary’s projected probability of mission success and effective raid size,” DARPA said in its Proposers Day notice.

Unfortunately, doing so will be easier said than done. Using hard-kill interceptors to knock down incoming ballistic missiles, which reach hypersonic speeds in the latter stages of their flight trajectory, is hard enough, even though they travel along relatively well-defined courses to get to their targets.

This has been described as trying to hit one bullet with another bullet. Engaging a hypersonic weapon would be akin to trying to hit a bullet that can erratically change course, is flying on a more level path through the atmosphere instead of space, and that is cruising at a consistent speed of five times the speed of sound or more throughout the majority of its flight.

That speed would also simply reduce the time available for any sensors, no matter how well placed or powerful, to identify the threat and then help cue the interceptors. This would only be more pronounced in a battlefield setting, where hostile forces might launch their weapons much closer to the actual target, further reducing the time available for U.S. forces to respond.

Of course, existing ballistic missiles already travel at hypersonic speeds in their terminal phase of flight, so existing defense systems geared toward intercepting those weapons at the end of their trajectory might be adaptable to knocking down hypersonic weapons, as well. Adding a space-based missile defense weapon layer could be another option to help shoot down boost-glide vehicles, which typically briefly fly near or above the earth's atmosphere.

Undersecretary of Defense Griffin has already proposed deploying 1,000 anti-missile interceptors in space and has discussed concepts for destroying incoming ballistic missiles during their initial boost phase, when they most vulnerable, using satellites carrying directed energy weapons. He has said the interceptor constellation concept would cost $20 billion, but has not yet offered any concrete details about the interceptors, how they would operate in space, or where the U.S. would position them to provide a useful defense shield. In 1993, the U.S. government canceled a proposed plan to place 4,600 interceptors in space, which had a price tag of $55 billion – more than $95 billion in 2018 dollars.

The key in any one of these scenarios will be a robust sensor network to alert U.S. forces to incoming threats, monitor them as they head toward their targets, and help aim anti-missile weapons at them somewhere along the way. But despite these various potential difficulties, the growing danger of hypersonic weapons is already too great to ignore. 

“In brief, we do not have systems today that give us globally, comprehensive, persistent, timely, multi-mode awareness of what is going on on earth, everywhere, all the time. We don't have that,” Undersecretary of Defense Griffin said at a conference earlier in September 2018. “The Chinese hypersonic threat is one that in today's world, we cannot see coming until it's too late.”

It will be very interesting to see what sorts of sensors, weapons, and other technologies come out of DARPA’s Glide Breaker program that might be able to counter hostile hypersonic weapons, or at least make an enemy think twice before employing them. We've reached out to DARPA for more information about the project and will let you know if and when we get any additional details. 

Contact the author: jtrevithickpr@gmail.com