The development of U.S. and allied sensors to detect and track hypersonic missiles is key to deterring their use and to destroying them via directed energy systems, Vice Chairman of the Joint Chiefs of Staff Air Force Gen. John Hyten said on Oct. 28.

“The most important thing about defending yourself against hypersonics is not the weapon,” Hyten told the Defense Writers Group. “It is not building your own hypersonics. It’s building a sensor that can see hypersonics. Right now, we don’t have real effective [sensors]. We can see some hypersonics, usually in post-event data processing, but we need to have sensors that see hypersonics, just like we see ballistic missiles. To be honest, if you look at our ancient radar architecture, the Ballistic Missile Early Warning System–Distant Early Warning (DEW) way back in the day, that architecture is focused solely around ballistic missiles. That’s what we do really well.”

“Any ballistic missile that takes off on the planet, we’ll see it, and I’ll get a phone call every time–actually an email now because it happens so often,” Hyten said. “But the ballistic missile threat is becoming a minority threat in the world. Cruise missiles, hypersonics–they’re the threat of the future. So we have to change our architecture where it’s not ballistic missiles that’s primary, and, oh by the way, if you look really hard we can see hypersonics and cruise missiles. We have to see everything because if you can see everything, you can actually deter it because you can have a warning architecture that will allow you to always have an assured second strike, and that’s deterrence, in a nutshell.”

Hyten said that future sensors should deal with ubiquitous missile threats, not just the threat of ballistic missiles coming over the North Pole.

L3Harris Technologies [LHX] and SpaceX are each building four satellites for the Space Development Agency (SDA) as an initial SDA stab at monitoring threats from hypersonic and other advanced missiles.

“When I look at the discussions we’re having with our allies, Canada included, radars are gonna be part of the solution,” Hyten said. “Radars against hypersonics are problematic…But there are all kinds of technologies, over-the-horizon radar technology. The Australians are building over-the-horizon radar capability. That’s useful technology. What we have to do with our allies, because this is a global problem, is that we have to build an integrated sensor architecture that can see these capabilities. It’s not one solution. It’s not one magic satellite or even one constellation of satellites that can see all the threats and just defend the nation, and if you tried to do that all in space, it’s one of those infinite budget problems that you can never catch up to. You have to integrate ground-based systems, air-based systems, space-based systems and develop an integrated architecture that can provide the warning that we need, and we have to do that at pace.”

Air Force Gen. Glen VanHerck, the commander of U.S. Northern Command (NORTHCOM) and North American Aerospace Defense Command (NORAD), has said that the modernization of the U.S.-Canadian North Warning System (NWS) should include the ability to detect low-flying cruise missiles, bombers, and small drones (Defense Daily, Aug. 17).

A successor to the 1950s DEW line, NWS, first fielded in the late 1980s, consists of 25 Lockheed Martin [LMT] AN/FPS-117 long-range radars and 36 short-range AN/FPS-124 radars. NWS provides early warning of possible incursions into U.S. airspace and covers nearly 3,000 miles across North America from the Aleutian Islands in southwestern Alaska to Baffin Island in northeastern Canada.

VanHerck has said that “ideally, we would like to go to an advanced system–over-the-horizon radar,” as NWS “is limited in its distance…which doesn’t allow us to see far enough out away from the homeland,” and that “there’s proven technology today that would give us domain awareness.”

NORAD modernization has been a topic of conversation among President Biden and Canadian Prime Minister Justin Trudeau.

To deter potential adversaries’ use of hypersonic missiles and destroy them, if launched, will require the Pentagon to step up its directed energy investment, which has lagged in the last several years, Hyten said on Oct. 28.

Hyten’s comments come after a recent Chinese test of a hypersonic weapon–one that DoD has declined to characterize due to classified intelligence. On Oct. 28, Hyten did cite a historical example of a Fractional Orbital Bombardment System (FOBS) fielded by the Soviet Union in the 1960s at the same time that the United States was developing one.

The SALT II Treaty, signed by former President Jimmy Carter and Soviet Premier Leonid Brezhnev in 1979 but never ratified by the U.S. Senate, banned FOBS “because they’re unbelievably destabilizing, because it’s very difficult to see them coming,” Hyten said. “The Soviet system was an RV (reentry vehicle) on the end of it, not a hypersonic glide vehicle.”

“The U.S. and the Soviet Union sat down and negotiated SALT II and said we need to get rid of those [FOBS],” Hyten said, and while the Senate did not ratify SALT II, “both parties abided by that [banning FOBS] element, and in 1983 the Soviet Union took their FOBS off alert, and no one’s ever deployed them again because they’re unbelievably destabilizing.”

“I hope that the world community would get together and realize that those are horrible weapons,” he said. “They appear to be first strike weapons back in the ’60s, and, if they’re ever built again, they’ll appear to be first strike weapons again. I hope nobody ever builds them.”

China has conducted hundreds of hypersonic missile tests in the last five years, while the U.S. has done just nine, Hyten said.