From Explosion to Innovation: How a Teen Founder Turned a Setback into Sequoia’s First Defense Tech Bet

teenage founder to become Sequoia’s first defense tech investment

In the high-stakes world of defense tech, one explosive incident didn’t derail a startup—it launched it.

Meet Ethan Thornton, the 21-year-old founder of Mach Industries, the defense tech startup that’s made waves as Sequoia Capital’s first-ever investment in the sector. Founded in 2023, Mach has already raised over $85 million and secured a contract with the U.S. Army. But its path to success was anything but smooth.

A Prototype Gone Wrong

Before the company secured Sequoia's backing, Mach suffered a dramatic and dangerous setback. While developing a hydrogen-powered weapon, a prototype exploded, sending shrapnel flying and injuring a team member. The blast was a stark reminder of the high-risk nature of defense innovation.

Speaking publicly for the first time about the incident at StrictlyVC in San Francisco, Thornton admitted that the explosion was due in part to the startup's limited resources.

“We were trying to self-fund it... and we didn’t have the money to run these procedures the way they should have been,” he explained.

Shutting Down to Start Again

Following the explosion, Mach Industries paused all operations until it could raise capital. That moment of reckoning turned out to be a turning point. After landing a seed investment from Sequoia Capital in mid-2023, the company returned stronger—with funding, a professional safety team, and clear vision.

Pivoting from Hydrogen to Next-Gen Weapons

One major change post-funding: ditching hydrogen. Thornton now calls hydrogen “probably a bad tech bet,” admitting it was too volatile and not yet viable at scale. But rather than folding, Mach pivoted to developing other advanced weapon systems.

Today, the company is working on:

• A new cruise missile

• A space-launched bomb called “Glide”

• A decentralized network of weapons factories dubbed Forge

These innovations are more than science fiction. They're actively drawing interest—and contracts—from the U.S. military.

More Than Just Engineering

What makes Mach Industries attractive to VCs isn’t just cutting-edge tech, but the startup’s ability to work directly with the federal government to transition prototypes into real-world programs.

“It’s not necessarily my ability to build these things,” Thornton said. “It’s more so our ability to get programs of record built around them.”

That distinction—between tinkering and real deployment—has earned Mach the trust of top-tier investors and defense insiders alike.

From a hydrogen-fueled accident to building weapons at the edge of space, Mach Industries is redefining what a defense tech startup looks like—and proving that resilience, focus, and strategic pivots can transform even the most explosive setbacks into launchpads