Castelion

Last week we paused the hustle for just a moment to celebrate the Castelion team and their families with a summer carnival. From dunk tanks and lawn games to tacos and snow cones, it was a chance to kick back, connect, and enjoy the crew that’s building something truly special. Grateful for this team and everything we’re building together. More missiles, fewer meetings. And the occasional ring toss.

JULY 4, 2025 Today we celebrate the country built on impossible odds and the people who still choose to build, serve, and defend it. From the revolutionaries of 1776 to the warfighters of today, America’s strength has always come from those willing to act when it counts. At Castelion, we’re proud to be part of that legacy - building the tools to protect freedom, deter war, and ensure America’s edge endures. Happy Fourth of July!

“All we’re really doing is bringing back what used to work for America...where you make an initial design over the course of a few months, analyze what you can, actually build it, and test it. Then, when you identify places where your assumptions or models were wrong … you make changes, ground your models in the real-world test results, and get back into testing immediately. Pace of learning and availability of hardware is the key to fast progress.” - Castelion's CEO, Bryon Hargis recently shared with Breaking Defense's Ashley Roque. Read more here: https://lnkd.in/gB4NKMsD

JUNE 24, 2025 Another step forward.

250 Years of the US Army A legacy of courage, discipline, and decisive action. Castelion is proud to build for the warfighters who move fast and lead from the front.

JUNE 4, 2025 Edith makes her debut. Each shot clears the path.

Three test launches. Ten days. One clear message: speed wins.   At Castelion, we believe hardware iteration should move as fast as the threats we’re preparing to counter. In just ten days, our team executed three flight tests - each one building on the last, each one unlocking critical data to drive rapid refinement.   Fast test cadence isn't just a milestone. It’s the foundation for building reliable, affordable defense systems at scale. When you fly often, you learn fast. When you learn fast, you win.

“History does not long entrust the care of freedom to the weak or the timid.” — General Dwight D. Eisenhower On this Memorial Day, we pause to honor the courage and legacy of Americans who gave their lives in service to our country. From the beaches of Normandy to the mountains of Afghanistan, their sacrifice has defended not only our homeland, but the enduring principles of liberty and self-determination. At Castelion, we are humbled by their example and are committed to building with the strength and urgency their memory demands.

May 18, 2025

Welcome to the family, Edith.   Our third mobile launch vehicle means we can now run multiple flight test campaigns in parallel. That means faster iteration, more real-world data, and more chances to break things (and fix them). Edith helps us move faster. Want in?