How a Hydrogen Explosion Turned a Young Entrepreneur into Sequoia's First Defense Technology Investment.

Mach Industries, Sequoia Capital's first investment in defense technology, has become a sensation in the industry, raising over $80 million since its inception in 2023. The company's founder, 21-year-old Ethan Thornton, started Mach while he was a student at MIT but decided to drop out to fully dedicate his time to his startup.

However, a few months before securing seed investment from Sequoia in the summer of 2023, the company faced a major setback when a hydrogen gun prototype they were developing exploded. This incident, which resulted in an injury to a team member and sent shrapnel flying, was initially reported by Forbes. During his appearance at StrictlyVC in San Francisco on April 3, Thornton publicly addressed the issue for the first time, arguing that the accident occurred due to a lack of safety resources. “At that time, we were trying to self-fund and didn’t have the money to follow these procedures as they should have been done,” he commented.

Following the explosion, Mach Industries “virtually halted all its work” until it secured funding from Sequoia Capital. With those resources now secured, Thornton announced that the company has a complete safety team and is collaborating with the U.S. military on the development of new weapons. Furthermore, the startup has shifted its original focus on hydrogen, a gas known for its instability. Thornton acknowledged that hydrogen had likely been “a wrong technological bet” that needed more development.

However, this change has not hampered Mach; rather, the company is now building different types of weapons, such as a new cruise missile and a bomb called “Glide” that can be launched from the edge of space. It has also recently secured a contract with the U.S. military and announced plans to establish a decentralized network of factories that it calls “Forge.”

According to Thornton, "the building of many prototypes" is one of the reasons investors have injected $85 million into the company. “It’s not necessarily about my ability to build these things, but rather our ability to work with the federal government and develop formal programs around them,” he added.