WASHINGTON — Defense officials have been sounding alarms about what they describe as a glaring national security vulnerability — a new class of ultrafast weapons being developed by China and Russia that would overpower U.S. missile defenses.

Detecting and tracking hypersonic missiles is a tough problem the Pentagon is trying to figure out how to tackle. A network of ground radars, satellites and interceptors defends the United States and allies from ballistic missiles from countries such as North Korea. But the system would be ineffective against non-ballistic weapons like hypersonic vehicles that fly at several times the speed of sound and maneuver in unpredictable directions.

The current ballistic missile defense shield is a layered architecture designed to provide multiple opportunities to destroy missiles and their warheads before they can reach their targets. The system includes space- and ground-based sensors, and sea-based radars for target detection and tracking. Ground- and sea-based interceptors, connected by a battle-management network, are positioned in key locations around the globe to fire against incoming missiles.

A hypersonic weapon would be aimed “at the gaps and seams” of U.S. missile defenses, said Tom Karako, a defense analyst at the Center for Strategic and International Studies, a Washington think tank. Conceivably, a hypersonic weapon could be launched atop an intercontinental ballistic missile, making it likely current U.S. satellites such as the Space Based Infrared System spacecraft operating in geostationary and highly elliptical orbits would detect and track its boost phase. But then the hypersonic weapon could separate from its booster and glide on top of the Earth’s atmosphere, flying erratically to its designated target. It could penetrate U.S. missile defenses by flying around radars and high in the atmosphere above the reach of widely deployed interceptors such as the Patriot and the Terminal High Altitude Area Defense systems.

The Missile Defense Agency believes the solution is a constellation of missile-tracking satellites in low and medium Earth orbits that would add a new set of eyes to the existing shield. MDA says sensors in space could track hypersonic threats from “birth to death” whereas ground-based radars could only detect such a threat once it comes over the horizon.

The commander of U.S. Strategic Command, Gen. John Hyten, has insisted that sensors in space are the most efficient option to detect hypersonic weapons and track them so they can be intercepted before they hit their intended target. “If you can’t see it, you can’t kill it,” he said.

But the Pentagon has not yet settled on the details of the so-called Space Sensor Layer, or whether it can afford such a system.

Congress is urging the Pentagon to deal with this issue sooner rather than later. It inserted $73 million into the Pentagon’s 2019 budget to get a program started. The projected total cost of a space sensor layer is still being studied.

“The funds Congress added are astonishingly little if you’re going to do a constellation,” said Karako. The Pentagon has stepped up the rhetoric about the threat of hypersonic missiles but does not appear to be in any hurry to deploy a defensive system, he said.

“We’ve been studying this for years. I don’t see $73 million as real progress; I see it as kicking the can,” he said. “If they were serious, it would be $730 million.”

Karako pointed to senior officials like Michael Griffin, the former NASA administrator now serving as undersecretary of defense for research and engineering, and John Rood, the undersecretary of defense for policy, who are “giving lots of speeches about why we need this” especially in the wake of China’s recent tests that show remarkable advances in hypersonic technology. Karako cited Chinese media reports that the country successfully tested three scale models of hypersonic aircraft over the past year. These hypervelocity aircraft could be repurposed as precision strike missiles.

The Pentagon, meanwhile, is waiting until the 2020 budget — which won’t be finalized by Congress for at least another year — to start a hypersonic defense program, he said. “This is not moving at the speed of relevance. There’s disconnect between what everybody is saying and what is actually being done.”

Pentagon spokeswoman Lt. Col. MichelleBaldanza said the department is “currently reviewing [Space Sensor Layer] funding.”

In a statement to SpaceNews, Baldanza said the Missile Defense Agency is analyzing proposals from companies that were given contracts Sept. 27 to design concepts for a space-based sensor layer. “The objective of the nine industry studies was to develop industry prototype concept designs. The studies are currently being reviewed, and they will support refinement of the requirements for the technology development phase.”

Each proposal “identified potential architectures to meet the requirements,” Baldanza said. “The final architecture will be selected after the technology development phase.”

Working through the Air Force-led Space Enterprise Consortium, the Missile DefenseAgency this summer awarded $1 million study contracts to nine firms — Lockheed Martin, Raytheon, Northrop Grumman, General Atomics, Maxar Technologies, Draper Laboratories, Leidos, Millennium Space and Boeing — to work on concept designs for a space sensor layer for hypersonic missile defense. The consortium initially had named the project Missile Tracking System, but MDA more recently changed the name to Space Sensor Layer.

Under a separate effort, MDA on Sept. 27 awarded 21 contracts of $1 million each to seven companies and Draper Laboratories to develop concepts for hypersonic weapon systems that would be used to shoot down enemy hypersonic missiles. The companies are BAE Systems, Boeing, General Atomics, L3 Technologies, Lockheed Martin, Northrop Grumman and Raytheon. The work will be completed by February 2019.

Defense and aerospace contractors are watching the Space Sensor Layer project with great interest despite uncertainty about future funding. One reason the effort has slowed is that the Pentagon has taken much longer than planned to complete a high-level missile defense review that lays out future plans. Industry sources said there are internal disagreements about how to handle the hypersonic defense piece. One of the debates is how the U.S. should work with allies as it plans a new system. Another contentious topic is whether the Pentagon can afford to embark on a costly procurement at a time when budgets are expected to flatten out.

The Trump administration’s five-year defense plan projects defense increases of just 1.2 percent between 2019 and 2023. That means that “any additional funds for MDA will have to come from the services,” said defense analyst Todd Harrison of the Center for Strategic and International Studies. A new constellation “may include a lower orbit space layer for tracking and target discrimination,” said Harrison. “That would be a new space program of pretty good size.”

Griffin has scoffed at claims that the Pentagon cannot afford a space-based sensor layer, and has argued that the technology already exists in the open market. He said the Pentagon would not have to spend tens of billions of dollars developing a system from scratch, a point echoed by Baldanza. “Our recommended approach for the [Space Sensor Layer] will leverage mature commercial technology and teaming with non-traditional contractors to minimize cost and schedule,” she said. “We have seen potential cost savings due to commercial technologies in the industry studies. As an example, teams have proposed using commercial satellite buses for their prototype concepts and designing their sensor payloads with components that are technologically mature.”

Industry perspective

Space industry consultant Mike Tierney said hypersonic missile defense is “seen as a big opportunity by everyone in the commercial market. Everyone is going to want to compete for a piece of that. It’s a new capability, and it has strong congressional support.”

Kenneth Todorov, a former MDA official and now Northrop Grumman’s vice president of missile defense solutions, said it is much harder to thwart hypersonic vehicles than traditional missiles. “You can’t predict the path, the impact point; they evade our radar coverage.”

These weapons could be used in multiple domains of warfare, he said — as tactical missiles to strike an aircraft carrier at sea, or as strategic weapons if they are nuclear tipped. “At the outset they can look like a ballistic missile, then suddenly we lose track, and the re-entry vehicle could end up being hypersonic.”

“Our sensors and command-and-control networks are not capable to counter this threat,” he said. “We need to start with a space layer that can acquire, track and execute a fire control solution, and we have to consider a command-and-control architecture from the get-go.”

Todorov said MDA asked each of the companies that submitted concepts to also provide rough estimates of the cost.

The foundation of a space layer for missile defense would be satellites and sensors, but it also will need artificial intelligence and other advanced technologies to process data and give commanders real-time updates, said Robert Zitz, senior vice president and chief strategy officer at SSL, the satellite-manufacturing arm of Maxar Technologies.

The data collected by the new sensor layer would be meshed with that from existing missile-warning satellites and other sources of intelligence, Zitz said in an interview. The military wants a “persistent” eye on the threat, he said.

“They understand that persistence is not going to come from a single orbital regime or single sensor. Persistence is putting all the pieces of information together,” Zitz said. “What they’re looking for from industry is an architecture to tie sources together.”

In a situation when a threat is detected, commanders cannot afford to “go through a time consuming and laborious process to get intelligence,” Zitz said. “The process has to be much more automated.”

The industry is developing “smart” satellites that perform onboard data processing, he said. “With smarter satellites that are integrated with each other, machine to machine capability is critically important.”

Zitz predicts the Space Sensor Layer will morph from concept to actual hardware in the coming years. “Capitol Hill is very supportive. All indicators are that there will be additional resources available to move to the next phase after the studies.”

Kay Sears, vice president of Lockheed Martin Space Systems, agreed that artificial intelligence will play a key role in “how you get data to decision makers at the speed of the threat.”

In hypersonic missile defense, there would be “complementary architectures,” she said.

“This is really important. A distributed constellation is not the answer to everything. It’s going to be a mix of orbits,” Sears said. “The key is to think through the entire end-to-end architecture, not just the space piece but how it all integrates on the ground.”

Karako cautioned that the program could get bogged down in studies unless the Pentagon soon starts to develop and test prototypes.

“There’s different views about the relative costs and benefits of different orbits,” he said. “That’s the right kind of conversation we should have. But [let’s] just move forward on something.”

This article first appeared in the Oct. 8 issue of SpaceNews magazine.