DARPA-Funded Study Proposes Vision For Hypersonic Production Facility

A future factory called the Hypersonic Production Accelerator Facility—for building potentially thousands of scramjet propulsion systems for hypersonic cruise missiles—may not need the U.S. Defense Department or the defense industry to pay the up-front costs for facilities and equipment.

With no or few capitalized investments demanding a lengthy return on investment, the additive manufacturing machines needed to produce the high-temperature materials required for scramjet propulsion could be refreshed or replaced in three-year cycles.

• HPAF shifts start-up costs to nonfederal sources
• Facilities and machines could be refreshed every three years

The entire supply chain—from the feedstock suppliers for the electron-beam welders to the prime contractors—could be co-located within the Hypersonic Production Accelerator Facility (HPAF). The vertically integrated process would be capable of producing, testing and qualifying materials for new designs in almost half the time and for about one-fourth the cost of a traditional distributed supply chain.

That vision for mass production of scramjet-powered vehicles has emerged from a two-year DARPA-funded study by the Applied Science & Technology Research Organization (ASTRO).

An unclassified summary of the study published by ASTRO in September proposes a new business model for producing scramjet-powered missiles, but defense officials say it could be applied to a wide range of advanced weapons.

“This effort was intended to inform us as we develop the concepts for [producing] affordable systems in large numbers where high-temperature materials and advanced thermal-management techniques will drive designs that have unique production requirements,” a Pentagon spokesman says. For example, the carbon-carbon material applied to rocket-boosted hypersonic glide vehicles also could benefit from the same approach, according to the study’s authors.

The ASTRO study seeks to answer questions that have hung over the Pentagon’s three-year-old rush to play catch-up with advances by Russia and China in hypersonic weapons: Who would pay the up-front costs to build an infrastructure of production and test facilities necessary to support U.S. weapon production? And would that infrastructure accommodate the rapid pace of change in the nascent hypersonic field, allowing quickly obsolete manufacturing processes and tools to be affordably replaced with state-of-the-art equipment in cycles of a few years?

According to ASTRO, a consultancy founded by a former DARPA manager, the answer would be to seek a dramatic split from the conventional model for producing advanced weapons. To start, the study proposes a new level of participation by state and local governments in defense production.

“A number of regions have talked about local and state support for having the [hypersonic production] facility located there,” Mick Maher, chief technology officer for ASTRO, says in an interview.

The published summary of the ASTRO study identifies nine potential sites for the HPAF: Seattle; Long Beach, California; San Antonio; Wichita; College Station, Texas; West Lafayette, Indiana; Huntsville, Alabama; Daytona, Florida; and Hampton, Virginia. The locations share a common trait: local access to existing hypersonic infrastructure.

“If you look at all of those places, there’s probably a wind tunnel nearby or an OEM,” Maher says.

The ASTRO study recommends that the Defense Department hold a competition in which those potential cities would offer bids of financial support to offset the up-front cost of establishing the HPAF. As part of the proposals, the competitive bidding could include offers to finance the capital infrastructure costs for the facility, production machines and tooling.

By their nature, scramjet propulsion systems make ideal candidates for additive manufacturing. Such processes can “grow” a part made of high-temperature materials, along with intricately designed internal passages to enable active cooling systems.

Thomas Bussing, former vice president of advanced missile systems for Raytheon, confirmed that additive manufacturing will play a key role in the production of the company’s scramjet design. “You could not build [scramjets] using conventional methods by the way cooling systems are structured,” Bussing said in a June 2019 interview. “Also, the larger segments—the inlets and bypass ducts—all of those things are basically done via additive manufacturing.”

Additive manufacturing makes the new generation of scramjet designs possible to build but creates certain financial pressures.

“If Lockheed Martin were to go buy a metal additive machine, that’s somewhere between three quarters of a million to a million dollars,” Maher says. “They don’t make that investment easily, and when they do, they don’t get off that horse easily.”

The ASTRO study proposes an HPAF financed largely by nonfederal sources, such as local and regional governments or public-private partnerships between governments and academia.

Those entities would own the HPAF, then lease access to the facility and the machines to the Defense Department to support production for a program of record. The Pentagon would then turn over the machines and the facility to the supply chain to build the scramjets.

“We’re saying the government doesn’t even need to get into the ownership piece,” Maher says. “It can provide the money to set the facility up and get it running. And then we can even provide project money on top of that.”

The concept bears faint echoes of an early description in late 2018 of the Pentagon’s vision for future hypersonic production by Patrick Shanahan, who was then the deputy defense secretary spearheading a review of industrial base policy. In remarks at a National Defense Industrial Association event on hypersonic manufacturing, Shanahan, a former Boeing executive, was keen to shift the cost burden of manufacturing infrastructure from industry to government.

“There are a lot of big companies in the United States, but they don’t have the balance sheet to make the investments in the infrastructure that we’re going to need,” Shanahan said in 2018. “I’d love to build the right facilities and then turn the keys over to someone to manage.”

The ASTRO study builds on that approach but suggests using local and regional governments to supplement or assume the Pentagon’s up-front costs to build a hypersonic manufacturing infrastructure within a few years.

The goal of using that approach is twofold. After nearly four decades of start-stop cycles in hypersonic technology development, businesses would not have to convince skeptical boards to spend heavily on up-front production equipment. The same burden upon the Pentagon’s budget also would be relieved. In addition, the industry and the military would not be disincentivized to invest in new additive machines and processes as they become available.

“If you buy equipment, that locks you into that time frame [to earn a return on investment],” Maher says. “Leasing it allows you to be much more flexible.”

The ASTRO study anticipates a regular cycle of manufacturing updates. The OEMs could “refresh” the additive machines to adapt to new technology. Alternatively, if a new manufacturing process emerges, the HPAF could be “reset” with different production tooling altogether. The refresh-reset cycle assumed in the study is set at three-year intervals, although Maher says the industry is still debating the ideal time period.

“If you change it too fast, you never qualify the process, so you never get to use it,” Maher says. “If you go too slow, you don’t get to take the advantage of what’s out there. So three years is somewhat controversial. It came down to what we thought made the most sense.”

When the Pentagon moves to establish a new base or production site, the location decision often reflects political considerations as much as operational needs. Those same political interests also usually drive defense contractors to disperse the supply chain to as many congressional districts as feasible.

The ASTRO study seeks basically the opposite for the HPAF. The entire supply chain for design, test and manufacturing would be co-located inside the facility. Each tier of the supply chain would be on-site, including the material feedstock supplier, factory equipment supplier, Tier 1 suppliers, contract manufacturer, lead system integrator and the Air Force program manager.

The concept for the vertically integrated campus emerged from a workshop of more than 100 industry representatives summoned by ASTRO in November 2019.

“You look at a traditional manufacturing path, and you’re back and forth across the country several times between heat treatments and machining places,” Maher says. “There’s a tremendous amount of time just lost in queue.”

The HPAF also would be sized to support multiple prime contractors working on different vehicles.

In August, the Air Force selected Boeing, Lockheed and Raytheon to compete for the Future Hypersonic Program, a planned follow-on to DARPA’s Hypersonic Air-Breathing Weapon Concept. Lockheed and Raytheon are participating in the latter; the first flight tests of each company’s design are scheduled for later this year. The Air Force has not defined an acquisition strategy for the operational prototyping program, but it may not lead to a traditional winner-takes-all contract award. Senior Pentagon officials have previously said they would prefer to maintain competition beyond development, with multiple designs competing for annual production orders.

To facilitate long-term competition, the HPAF would be designed with up to four bays, allowing for three OEMs and their supply chain to occupy one area each. The fourth bay would be set aside as a demonstration site, where new production technologies could be showcased and used for experiments, Maher says.

“The goal is to have the primes bring in their supply chain to work in a secure environment to protect their intellectual property,” a Pentagon spokesman says.