Requirements for success in hypersonics

In 1909, amateur aviator Louis Blériot became the first to fly a heavier-than-air craft across the English Channel, earning his Blériot XI monoplane a place on the Paris Air Show’s inaugural poster just a few months later. It’s a gross understatement to say much has changed since then.

Visitors to June’s 2025 Paris Air Show can look forward to the roar of cutting-edge aircraft passing overhead, followed by equally thunderous applause from an enthusiastic crowd. But above all, they can anticipate that practically everything they see and hear will be faster and more powerful than ever before.

Fast times

Practically all rockets can reach the 3,836mph (6,174km/h) threshold the scientific community considers hypersonic. An increasing number of passenger and military aircraft are closing in on this much-vaunted speed, as well as a host of cruise missiles, missile interceptors, and hypersonic gliders.

A current jetliner needs five hours to fly from New York to Los Angeles; a plane traveling at Mach 5 could make the same trip in about 45 minutes.

Lighter and faster, yet stronger and more fuel-efficient is the driving goal today, all of which requires a unique mix of advanced engineering, manufacturing technology and, above all, experience.

The right stuff

Advanced Structural Technologies Inc. (AST) of Oxnard, California specializes in spin- and flow-formed components such as nose cones and injector rings, chamber liners, diaphragms, fuel tanks, nozzle liners and extensions, and similar rocket components, many of them destined for supersonic and hypersonic use. Marshall Dormire, the manufacturer’s business and product development senior leader, calls it artful engineering.

“I have to remind people that we don’t design any of these parts, even though our customers are constantly challenging us to help them make their designs better,” Dormire says. “They’ll call and ask if we can produce a certain shape, or work with a special, often proprietary alloy, or eliminate seams that would otherwise require welding or mechanical fasteners, thereby combining two or more parts into one. In most cases, we can do all this and more, but sometimes we have to tell them, ‘No, don’t build your rocket motor that way,’ and show them a better, often more cost-effective alternative, one with lighter weight and higher strength.”

Demand for advice like this is on the rise, which is why AST continues to enjoy significant growth. To meet these demands, management recently expanded its manufacturing footprint to 250,000ft2 after remodeling a nearby building. At the same time, AST invested in new CNC equipment to fill the space, chief among them a massive spin forming machine from MJC Engineering of nearby Huntington Beach.

AST Principal Engineer Sean Ptacek was among the team that spec’d the new machine. He says everyone is impressed with its 500hp spindle and 230,000 lb of axial force, and enjoys working on its state-of-the-art Siemens Sinumerik One control, but notes the ability to spin workpieces up to 110" across and a bit more than 2x that in length has opened doors to new business opportunities.

Some of these are for hypersonic vehicles. Although AST was already processing a wide range of copper alloys along with Ti-6Al4V titanium, refractory metals such as niobium, austenitic stainless steels, and heat-resistant superalloys (HRSA) including Inconel 625 and Haynes 214, they’re now better equipped to form precision parts from these materials more quickly and accurately than before, and in much larger sizes.

The hot rod shop

AST can cold-form very thick plate, a capability unavailable until now. Designing a machine from the ground up was a great move for AST. “We were able to spend time with our partner MJC to get everything just the way we wanted, with specifications based on our years of experience with spin- and flow-forming,” Ptacek says.

“I had a customer’s engineering department call, wondering if there was a typo with the elongation test values we’d supplied. I assured them it wasn’t an error, only the fact that we’re able to achieve fantastic metallurgical properties, basically giving them a completely different materials book to work from. It’s an amazing machine.”

Dormire agrees. “Sean’s done a good job of explaining the new machine is more capable and powerful and convenient to operate, but it’s important to point out that much of what we called for in its design also represents the upgrades and retrofitting we’ve done to our legacy equipment throughout the years. In addition, his comment about improved material properties isn’t new, although it’s clearly now possible on a much larger scale.”

The AST advantage

Ironically, this is one of the challenges Dormire faces when customers looking to understand AST’s capabilities ask him for an equipment list. “It doesn’t do justice to all we can do here – it would be like asking an artist, ‘Who makes your paint brushes?’” He laughs, pointing an arm at the production floor. “I like to call that the hot rod shop because very few of our machines represent the model number assigned at the factory. If one of the original designers were to visit us, he’d take one look and say, ‘Hey, you can’t do that. You’re going to break the machine.’ My response would be to tell him our machines do it all day, every day.”

AST doesn’t need to carve parts out of expensive blocks of high-strength materials as with CNC turning and milling processes. Doing so is not only extremely wasteful, but you can’t control grain flow as with spin forming. Because of their capabilities, Dormire says AST can often reduce the customer’s material spend by 50% to 90%, depending on their design and where they are in the production process.

Flow forming, spin forming, and rotary forging represent the intersection of metals and mechanics, of art and engineering science.

“It’s precisely due to this unique, often challenging intersection that we’re able to deliver components – hypersonic and otherwise – that can’t be produced any other way,” Dormire explains. “Our spin forming and heat treat processes can simultaneously increase part strength while reducing weight and development costs. Mach 5 is very hard to achieve. We can get customers there more quickly, efficiently, and with far fewer surprises; we help to remove the barrier to entry.”

Advanced Structural Technologies Inc.
https://astforgetech.com

MJC Engineering
https://mjcengineering.com