The second thing to know about hypersonics is that China and Russia have them, and the U.S. doesn’t—not really. It’s not for lack of trying: Despite years of research costing billions and some successful tests, the U.S. has yet to fully field a hypersonic missile of its own due to testing complications and production issues. The tech’s been around, but it’s been expensive and difficult to produce at scale. ... That’s the chasm that startup Castelion, valued at $13 billion, is betting it can close, even if the defense giants have so far fallen short. “Humans have done it, just not Americans,” says Castelion CEO and cofounder Bryon Hargis. “I firmly believe it’s doable.” ... “This capability is needed now, and you have to sprint directly at what the country needs,” says Kreitz, Castelion’s CFO. Hypersonics are effective not just as weapons but, even more essentially, as deterrents, Kreitz argues. “It’s really important we have a credible deterrent that we pass down for generations to come,” adds Hargis. He gestures at a Mad Men-esque poster in Castelion’s mid-century office. “Cheesy as it is, this was the first poster we ever made for the company,” he explains. “You can see the tagline was: ‘Win before it begins.’” Of course, deterrence only has a chance if the weapons exist. And recent conflicts have created an unmissable urgency, Kreitz says. “This is the capability that will define warfare in the 2030s and beyond,” he said. “The campaign was basically large, sustained volleys of back-and-forth long-range fires. That’s what the future of warfare will look like.” https://archive.li/fQwF0 https://fortune.com/2026/10/31/hypersonic-castelion-defense-tech-startup/