Defense aviation startup Hermeus just closed a $350 million funding round to accelerate development of autonomous hypersonic aircraft, the company announced Tuesday. The Atlanta-based startup is riding momentum from two successful flight demonstrations and plans to push its next test vehicle past the sound barrier. The massive raise signals growing investor appetite for next-generation defense tech as the Pentagon races to counter hypersonic threats from China and Russia.
Hermeus just secured $350 million to turn science fiction into battlefield reality. The defense aviation startup announced the funding round Tuesday, marking one of the largest raises in the emerging hypersonic sector as investors bet big on autonomous aircraft that can fly faster than five times the speed of sound.
The timing isn't coincidental. Hermeus is coming off back-to-back successful flight demonstrations of its autonomous test vehicles, building credibility in an industry where vaporware often dominates headlines. The company told TechCrunch it's now preparing for its most ambitious test yet - pushing past supersonic speeds as a stepping stone toward its ultimate hypersonic goal.
Founded in 2018, Hermeus entered a crowded field of startups promising to revolutionize high-speed flight. But while competitors focused on commercial applications like ultra-fast passenger jets, Hermeus zeroed in on military contracts from day one. That strategic choice is paying off as the Department of Defense accelerates hypersonic weapons development to match capabilities China and Russia have already deployed.
The company's approach blends old and new. Rather than reinventing propulsion from scratch, Hermeus adapted existing turbine-based combined cycle engines - the same basic technology that powered the SR-71 Blackbird. The innovation comes in miniaturization, automation, and AI-driven flight controls that eliminate the need for human pilots in extreme conditions.
Those two recent flight tests validated the company's core thesis. While Hermeus hasn't disclosed specifics about altitude or speed achieved, the demonstrations proved their autonomous systems could handle takeoff, navigation, and landing without intervention. For investors, that tangible progress separates Hermeus from paper concepts that have burned through defense budgets for decades.
The $350 million infusion will fund the supersonic test campaign and accelerate development of operational prototypes. Hypersonic flight presents brutal engineering challenges - vehicles must withstand temperatures exceeding 2,000 degrees Fahrenheit while maintaining precise control at speeds where milliseconds matter. Materials science becomes as critical as aerodynamics.
Hermeus isn't alone in chasing hypersonic military applications. Traditional defense giants like Lockheed Martin and Raytheon are pouring billions into hypersonic missiles and aircraft through Pentagon contracts. But startups bring a different calculus - faster iteration cycles, lower overhead, and willingness to take technical risks that large contractors often avoid.
The commercial implications extend beyond defense. If Hermeus cracks hypersonic flight economics, the technology could eventually enable sub-two-hour flights between any two points on Earth. The company has hinted at commercial ambitions, though military applications remain the near-term focus and revenue driver.
Investor appetite for defense tech has exploded since Russia's invasion of Ukraine exposed gaps in Western military capabilities. Venture funding for defense startups hit record levels in 2025, with hypersonics, autonomous systems, and AI-powered warfare attracting outsize attention. Hermeus' raise suggests that momentum isn't slowing despite broader tech funding pullbacks.
The upcoming supersonic test represents a critical milestone. Breaking the sound barrier is table stakes - the company must prove it can then transition to hypersonic speeds while maintaining autonomous control. That's where physics gets truly unforgiving and where most experimental programs have historically failed.
For the Pentagon, programs like Hermeus offer an alternative to traditional acquisition timelines that stretch across decades. The military wants hypersonic strike capabilities operational within years, not generations. Startups willing to move fast and accept failure as part of rapid iteration align better with that urgency than legacy contractors optimized for massive, slow-moving programs.
Hermeus' $350 million raise cements its position at the forefront of the hypersonic startup race, but money alone won't solve the physics problems ahead. The supersonic test will show whether the company can bridge the gap between subsonic autonomous flight - now proven - and the extreme conditions of hypersonic speeds. If successful, Hermeus could reshape both military aviation and eventually commercial flight. If the test fails, it joins a long list of ambitious aerospace programs that looked promising on paper but couldn't survive contact with reality. Either way, the Pentagon's hypersonic urgency means we'll get answers faster than the traditional defense industry timeline would ever allow.
