Mach Industries' Ethan Thornton on baking rocket motors at scale

Key points

Key takeaways from the Relentless interview with Mach Industries founder and CEO Ethan Thornton (2026):

Building America's biggest solid rocket motor factory. Mach is industrialising a 117,000 sq ft energetics plant — with a second roughly twice the size opening within four months — aiming to mass-produce hundreds of thousands of solid rocket motors a year within two years, retrofitting ~200 rented bunkers to store the explosives.

Why solid rocket motors. Thornton argues warheads and solid rocket motors — after jet engines — are the single biggest rate-limiting factor on producing weapons systems at scale, so Mach is attacking that bottleneck "super aggressively."

The Squadum acquisition. Rather than spend five years on licensing, Mach acquired Squadum, a lab founded by former Air Force solid-rocket-motor engineers that had won hundreds of design contracts for the Air Force, NASA, DARPA and SOCOM over two decades. Thornton says he generally hates acquisitions but made an exception here.

"Jet engines are plumbing, solid rocket motors are baking." The casting and curing process is an arduous, arts-and-crafts-like procedure — mixing a dough-like propellant, pouring it into casings and curing at temperature — that Mach is trying to fully automate to take every human out of the loop.

Supply-chain as strategy. Precursor materials for much of this are made at a single US facility already sold out three years ahead, so Mach is working to bring partners on-site to redo the precursor process and secure its own supply lines.

Half the revenue is merchant supply. Roughly half of Mach's revenue comes from selling components and energetics to other companies rather than its own finished products — a hedge that also builds out the broader defence industrial base.

From a high-school garage. Thornton has been making solid rocket motors since building rocket candy in his garage in high school, and its Pike airframe already flies on a solid rocket motor today.

Read more: Relentless