Lockheed Martin's hypersonic Air-launched Rapid Response Weapon (ARRW) is intended to travel 500 miles in just 10 minutes once fired from a B-52 bomber. That's 3,000 mph, versus about 500 mph for a conventional weapon. Mike Tsukamoto/staff; Lockheed Martin; USAF
Photo Caption & Credits

Catching Up on Hypersonics

March 26, 2021

As flight-tests begin, the military must overcome shortages of talent, test capacity, and supply.

Flight-testing U.S. hypersonic missiles is about to take off—perhaps as often as once every six weeks over the next four years—but the Pentagon still has a long way to go to create the “ecosystem” of skilled people, test facilities, and industrial capacity needed to build such weapons at scale.

The urgency is great, because China and Russia have already fielded their first hypersonic weapons, and it’s expected it will take the U.S. several years to catch up. For that reason, the U.S. is on a crash program to field weaponized prototypes in the next two or three years, followed a few years later by more elaborate and mature systems built in larger numbers. However, that won’t happen without building the infrastructure to produce the still-experimental vehicles. 

“There are two major drivers to our hypersonic investment strategy,” said Michael E. White, the assistant director for hypersonics in the office of the Undersecretary of Defense for Research and Engineering. One is that “the adversary has aggressively pursued their hypersonics capabilities and they’re fielding them today.” The other is that those missiles challenge the U.S. in nearly every fighting domain, and to get back in the game, the U.S. has to be able to match them, he said.

I will never be satisfied until we’re flying routinely. … And we’re not flying routinely, yet

Michael White, assistant director for hypersonics, DOD

On a battlefield of the near future, White observed, “the adversary is launching long-range weapons that travel 500 miles in 10 minutes, and our weapons take an hour to fly 500 miles.” The U.S. “can’t allow” that asymmetry to continue, he asserted. 

The Pentagon and Congress are serious and in agreement about the need to make hypersonics happen, White said.

Budgetwise, “I think we’re in a really good spot,” he said. “We went back and looked at the 2016 budget, and in that budget, we were spending about $340 million. And now we’re spending about $3.5 billion, so we’ve increased, in four years … by a factor of 10.” Congress has been “very supportive,” he said.

China displayed DF-21 “carrier killer” and DF-26 “Guam killer” missiles in a 2019 military parade, and Pentagon officials later judged these were operational, and not just mock-ups. Russia announced operational capability with the Avangard—a maneuvering, nuclear hypersonic glide vehicle carried on an intercontinental ballistic missile—and the Kinzhal, an air-launched tactical hypersonic missile with a range of 1,200 miles. Officials said both China and Russia are working on improved versions of those weapons, while developing numerous variants and other hypersonic munitions.

“They recognized the significance of hypersonics and made the decision to transition into system development before we did, quite frankly,” White said. 

TAKING THE LEAD

The U.S. has developed a portfolio for air, land, and sea launch platforms to “challenge, and if necessary, defeat” other adversary high-end capabilities, according to White. Once the forces that “hold our traditional forces at bay” have been beaten back by hypersonic weapons, “it really opens the floodgates to what we can bring … with our conventional forces.” Hypersonics has become the key enabler, he noted.

“The things that hold you at risk, you’d like to defeat with a weapon you know will get through … and do it quickly.”

But the industrial base to build hypersonic vehicles in numbers doesn’t exist yet.

“If, tomorrow … you said, ‘I want to start building a thousand hypersonic missiles a year,’ we wouldn’t have the capacity to do that,” White said. He’s developed roadmaps that spell out “what … we need to do to ensure that, as we get into the mid-2020s,” the industrial base will be churning out hypersonic rounds.  

White set up a “war room” last year to create the enabling infrastructure and intellectual horsepower to master hypersonics, and “the results … are expected over the next couple of months,” he said. “Program by program, we’ve identified key needs,” and the work done will point industry toward the investments necessary.

Hypersonic missiles will be expensive for the foreseeable future, White said, and “you don’t get to a point where everything becomes a hypersonic weapon.” They will instead be pathfinders.

“Hypersonics … will be the ‘break down the door’ weapon,” said Mark J. Lewis, Executive Director of the National Defense Industrial Association’s Emerging Technologies Institute. Lewis was the Director of Defense Research and Engineering for Modernization, and White’s boss at the Pentagon, until mid-January.

There are “some reasons for concern” about the developing hypersonics ecosystem, Lewis said.  First, “we don’t have the test facilities that we need.” The various hypersonic programs are “kind of climbing over one another to get to get access to wind tunnels,” he observed. 

Propulsion testing is especially problematic. For a combined-cycle engine—one that uses conventional, turbine-like propulsion to get to high velocity, and then transitions to a scramjet for hypersonic speed—“we really don’t have anything that will let us do that adequately on the ground,” Lewis said. For any wind tunnel work in the U.S., “you have very limited choices. … So that’s an area that needs investment.”

Availability of flight-test ranges is another problem. Again, programs are competing for range time, not only with each other but with “all the other things we want to do flight-testing on,” Lewis said. 

“We’ve got some amazing [test] infrastructure, but it’s very old,” said Maj. Gen. Christopher P. Azzano, commander of the Air Force’s Test Center at Edwards Air Force Base, Calif. “We’ve put sustainment money into it over the last few years, but it needs more.”

Azzano said that last year, at the direction of former Air Force Secretary Barbara M. Barrett, “we … prepared a number of different investment portfolios to try to improve our capacity,” both in tunnels and test ranges. But “right now, there are just too many pressures on the Air Force budget to address all of them.”

He acknowledged that the air test ranges are “under some strain,” given the number of competing efforts, and some programs “think they’re ready to go, and they’re not.” To be a good steward of the range space, though, Edwards is compelled to schedule range time at 100 percent. Anything less is “a wasted opportunity,” Azzano observed.

The Test Center is experimenting with a concept called SkyRange, which uses unmanned aircraft to clear the test space and relay telemetry, he said, in an effort to do more with the range space already available. But hypersonics testing, with “long fly-outs” will be a challenge, Azzano admitted.  

The first test flights of the ARRW, designated AGM-183, were scheduled for March 2021. Captive-carry tests were completed last summer and fall. Giancarlo Casem/USAF

White’s “war room” should deliver a plan on how to address the paucity of tunnels. Though the results may be classified, the answer will include partnering with NASA and academic institutions.

Computational fluid dynamics—simulation—is part of the “three-legged stool” supporting hypersonics development, along with flight-tests and tunnels, White said, but of the three, flight-testing is the most important. “It’s hard to represent everything in a wind tunnel that you’re going to get in flight.”

For high mach numbers coupled with intense heat, there’s only one tunnel—a NASA asset—that can create the environment. But “we’ve made additional investment” in the Arnold Engineering Center at Tullahoma, Tenn., and “we’re evaluating additional investments in partnership with NASA,” White noted. Tunnel investments amount to about $500 million next year.   

Besides the shortage of tunnels and ranges, Lewis is worried that the U.S. has gotten “rusty” on developmental flight-test. It’s “both a science and an art. It takes practice. I worry about our lack of practice, and so we need to get back into that.” 

To “deliver on the time scales required, I think we need to be testing on the ground and in flight at a pretty high pace,” he said. Stepping up the tempo of testing will also make all the steps involved—range safety, telemetry, checklists, etc.—more routine and reduce errors that can stop a program in its tracks. He said the X-15 hypersonic rocket plane program in the 1950s and ’60s was a good model to follow: It flew, on average, every two weeks for nine years, generating a “phenomenal” knowledge base. Without constant testing, “we’re not building the expertise we need.”

Hypersonics leaders want the pace of flight-testing to match the twice-monthly flights of the X-15 from 1959 to 1968, which rapidly generated volumes of data about the hypersonic environment, materials, and propulsion. Here, an NB-52 mother ship makes a low pass over a just-landed X-15. NASA

MORE TESTING

Lewis thinks it’s also important that “you … take intelligent risk,” on “the ultimate goal of the program.” When the biggest risks lie elsewhere, “you set yourself up for failure. And we’ve seen some of that.” For example, he said, “if you’re going to test something that flies at hypersonic speeds, for cryin’ out loud, you don’t want the biggest risk to be the rocket motor that gets you up to hypersonic speeds.” He also believes flight-testing has gotten too cumbersome. “It’s amazing how many people can say ‘no’ to a flight-test.” Too many competing programs are fighting over range access, he said, and “if you miss your flight window … your next window is going to be two months later. And silliness like that.” 

White said, “We’re going to fly a lot more than we ever did.  … We’ve got between 40 and 50 flight-tests planned for the next four years,” and the Pentagon’s Test Resource Management Center is “investing in ways that will allow us to increase the flexibility and availability of flight-test ranges.” 

However, he doesn’t want to substitute speed for “engineering rigor” in planning and executing tests. Typically, he said, in the interest of speed, “little things … bite you,” and when tests fail, it’s usually not because of some problem with a hypersonic design, but “failing the systems engineering rigor test … over the last decade or so.”

He said he’s “pulled together a team to do a best systems engineering practices for flight-testing,” and the lessons learned will be passed along to the entire flight-test community.

“I will never be satisfied until we’re flying routinely,” White said. “And we’re not flying routinely, yet.” Key contractors have “heard me give them the systems engineering rigor speech more than once,” he added. 

While details are classified, two hypersonic missiles that were to make their first air-launched, free flight late last year didn’t do so. Sources said the snafus were due to amateurish mistakes rather than a failure of the hypersonics technologies.

Contractors are stepping up their investments in hypersonic development, test, and production capabilities, Lewis noted. This includes not only major primes, like Lockheed Martin, Northrop Grumman, and Raytheon Technologies, but “even if you drop a tier,” there are lots of companies elbowing for position. “Look at companies like Leidos,” which was until recently mainly a consultancy and services outfit. “They purchased Dynetics,” which does high-speed aerodynamic hardware, “so they’re all-in on hypersonics.”

But the U.S. shouldn’t depend solely on the primes and top sub-primes, Lewis said.

“I worry about the diversity of the industrial base,” he asserted. “We’ve got a lot concentrated in a few companies,” and if they are all working on a large number of projects, “it’s hard to see how they could put their ‘A’ team on everything.”

Consequently, the Pentagon has worked hard to encourage and help finance some small businesses that can contribute to the knowledge base. While these smaller companies may not be able to manufacture thousands of weapons, they may have innovative solutions on materials and thermal management; two areas critical to the success of the hypersonics push.

“The current glide bodies leverage high-temperature carbon composite materials that take a long time to build,” White explained. “If we can leverage innovation in the small companies that allow us to do … development … and the buildup process much more rapidly,” it will have “dramatic impact on the ability to reach our capacity goals.”

Thermal management is essential because of the extreme temperatures on the nose and leading edges. 

“We have to have a vehicle skin … that can handle excessive temperatures and stay intact, and not only [that] but maintain its geometric integrity,” so that complex shapes and inlets will function as designed across a flight of hundreds to thousands of miles. 

Australia is a natural partner country for hypersonic testing and research cooperation. Here, a rocket launches from the Woomera Test Range, Australia, May 2016. The desert range could be a coveted hypersonic weapons testing location. Australian Department of Defense

MAKING THE GRADE

White noted that one feared problem—that a layer of plasma around hypersonic missiles would block communications—has not materialized. Plasma layers also seem not to “affect subsystems.”

 Lewis would give the materials ecosystem a “B,” when “a couple of years ago, it was a ‘C,’” he said. “Especially in high-temperature materials, … we really took our foot off the gas pedal” in the 2000s and 2010s. The research done was “not nearly enough for a robust ecosystem.” Over the last few years, “we’ve really stepped up in the high-temperature materials, not only in the basic research level, but in development, manufacturing.” He added, “I think we’re doing well, but we should always be doing better.”

To ensure there’s enough talent to go around, the Pentagon has helped create an Applied Hypersonics University Consortium. Under the Joint Hypersonic Transition Office (JHTO), its goal is to attract and grow experts in rocket and air-breathing propulsion, materials, heat management, and systems engineering to meet the demand that will come as hypersonics balloons into a major sector of the aerospace industry. The university lead is Texas A&M, “and they’ve got something like 50 universities now,” Lewis noted. The participants aren’t just the “traditional” aerospace schools, either, but some who are making their entrée into aerospace materials and “people working in controls and system design,” he noted.

The availability of talent is not a crisis, Lewis said. Although industry leaders express concern to him about the hypersonic workforce, they haven’t told him they’re having trouble hiring. 

The 10-person JHTO was set up in April 2020, and has a $100 million annual budget. It moves money around among hypersonics-enabling projects to get “more bang for the buck” and “make sure we’re focusing on the things that will get us … the capabilities we really need,” its director, Gillian Bussey, said in a November 2020 speech at the Technology and Training Corporation. 

Among her tasks, Bussey said, is to help bridge the so-called “valley of death” that stands between promising research and programs of record. University professors were finding that “when their work starts to get somewhere that’s relevant” to the Pentagon’s hypersonics enterprise, “the funding kind of stops” because the research category shifts from the basic research to the applied research accounts, and “it’s a lot harder for them to get funding.” She’s working to alleviate that problem.

The JHTO also facilitates knowledge- and resource-sharing among the services. “We’re reducing waste,” she asserted. “We’re coordinating and collaborating,” getting experts from NASA, the services, and academia working together to solve problems.

Lewis said he’s been struck at the sharing of knowledge among the services. Usually, “they only pay lip service to coordinating, but … I saw absolutely no limits on knowledge sharing. … It’s a really good news story.” The Army and Navy especially are “joined at the hip” in solving their surface-launched problems, he said.

The JHTO is reaching out to other countries as well—notably Australia—and seeks to “tap into nontraditional performers … to help them advance, to help us,” Bussey said.

Besides a long history of “very substantial” contributions to the field of hypersonics, Australia has a “national enthusiasm” for it, Lewis said. Australia also has the Woomera Range Complex, “where you can test early and often and crash on a desert floor and pick it up and look at what happened.” Australia also flies the F/A-18. “That means, anything the U.S. Air Force does with Australia automatically builds in a path for connectivity to the U.S. Navy. So they can … help us with connectivity between our services.”

Further out—perhaps in the early 2030s—White sees reusable hypersonic systems. They could be used for penetrating intelligence, surveillance, and reconnaissance work—a successor to the SR-71 of the 1960s to 1990s—or possibly as the first stage of a two-stage-to-orbit craft.  Will those systems be manned? White’s unsure, but “the Air Force has got point on putting together a strategy to get us a reusable, long-range hypersonic capability.” 

Lewis said he’s concerned that after all the effort to create the hypersonics ecosystem, a new administration offers an opportunity for opponents of the technology to derail the effort, and put the U.S. at a serious future disadvantage. 

“You still have folks coming out of the woodwork, mischaracterizing how hypersonics would be used,  mischaracterizing their capabilities,” and drawing the wrong conclusions. “That worries me,” Lewis said. 

“The debate is over. Every time we war-gamed the peer competitor scenarios, the difference between having hypersonic capability and not was the difference between winning and losing. It was that simple.”