
Bryon Hargis
317 posts



"In what world is hurling half an F-35 at somebody an effective way to deter them?" For decades, a single hypersonic missile has cost as much as $50 million. @hargsb built SpaceX's Starshield business before founding @Castelion to make them affordable at scale, and keep America safe. Watch @AlexaLiautaud in conversation with Bryon. Chapters 00:00 — From South Georgia to Rocket Scientist 05:20 — Watching SpaceX Before Anyone Believed 08:22 — Quitting a Safe Career to Roll the Dice 13:23 — Breaking Into SpaceX 16:42 — Building Starshield and Why He Left SpaceX 22:56 — Peace Through Strength and the Case for Hypersonics 28:14 — The Hypersonics Problem No One Solved 31:10 — The SpaceX Playbook Everyone Gets Wrong 35:58 — Blackbeard's 10-Year Vision 41:50 — Who Succeeds at Castelion 49:00 — Inside the World's Largest Hypersonics Factory

We have two exciting announcements today as Cantos turns 10… First, we closed our new fund earlier this year. Canto IV is a $70M fund purpose-built to lead pre-seed and seed rounds. We oversubscribed, wanting to keep it right-sized for being a founder's most aligned first partner. Second, we launched our new look with help from our friends at @asimov_co! Cantos is so-named as an ode to epic poems, where grand stories are written in "cantos" rather than chapters. We view founders as the protagonists of today's epics and seek to back those whose deeds become the stuff of legend. Our new website is a testament to the scale of their ambitions, with visions from a future they will have shaped. Resonat in Æternum 🖋️






.@LockheedMartin announced the Next Generation Glide Body (NxGB), a hypersonic capability designed for survivability, scalability and deterrence. Built to provide an affordable, operationally relevant long-range strike option. Click for more:


It was an honor to host @SecArmy at our headquarters. As threats evolve, producing hypersonic missiles rapidly at scale is required to build the American arsenal. We are grateful for the Army’s trust as we deliver the best munitions to protect our warfighters.



SITUATION DETECTED: The Department of Energy has issued a conditional $17.5B loan commitment to finance 10 large-scale Westinghouse AP1000 nuclear reactors across the US.



We're proud to share the @USNavy has awarded Castelion a $23.4M fixed-price order for 50 Blackbeard Hypersonic weapons, our first delivery order for the program. The award marks an important step in Blackbeard's transition from development and flight testing toward operationally relevant production. "Blackbeard was designed from the beginning to support our nation's conventional deterrence," said @hargsb, our Co-Founder & CEO. Read more: castelion.com/news/u-s-navy-…


K2 Space has been confirmed as a satellite bus provider for the @USSpaceForce Protected Tactical SATCOM-Global (PTS-G) initiative, which will launch to GEO in 2028. This announcement is a milestone for K2 as our first participation in a Pentagon program of record. Under the award announced by @USSF_SSC earlier this week, K2 will supply a satellite to our partners at @SESSpaceDefense, one of two primes on the contract. K2’s large, resilient satellites are built with the power and mass to deploy the anti-jam capabilities and consistent communications that the PTS-G constellation requires. Read more here: spacenews.com/k2-space-rocke…

We're partnering with @Saronic to launch Blackbeard from their Marauder (MUSV), a first-of-its-kind capability. "Blackbeard and Marauder will give our warfighters more shots, from more places, with fewer constraints," said our co-founder and CEO @hargsb. At-sea demonstration targeted for 2027. Read more here: castelion.com/news/saronic-a…

We're excited to join forces with @Castelion to integrate the Blackbeard hypersonic missile with our Marauder MUSV, demonstrating a first-of-its-kind maritime hypersonic launch capability. By pairing autonomous maritime platforms with hypersonics, we are advancing a more distributed and survivable approach to deterrence. Together, we're working to increase capability and capacity by combining autonomous maritime and hypersonic strike capabilities that are more affordable, scalable, and faster to field. With a demonstration targeted for 2027, both companies are investing in the production infrastructure needed to deliver these systems to the warfighter at greater scale and speed. Read more here: medium.com/saronic-techno…




"I want to leave a safe world for my kids. This is what I got." Bryon Hargis (@hargsb) is the founder and CEO of @Castelion, a defense startup building hypersonic missiles the way SpaceX builds rockets: fast, iteratively, and cheap enough to produce in quantity. His conviction is that America does not have a weapons problem. It has a manufacturing and learning rate problem. And that gap is more dangerous than any single technology demonstration. Timestamps (0:00) Intro (4:01) Why America needs hypersonic missiles (12:05) The missing middle ground in deterrence (19:40) How hypersonics differ from ballistic missiles (25:05) The economics of defensive vs. offensive systems (28:21) How SpaceX differs from traditional aerospace (37:40) Why Bryon chose to build in defense over space (42:42) Key factors that drove Castelion’s success (1:01:06) The importance of lower costs and quicker manufacturing (1:10:04) Book recommendations Thank you to the partners who make this possible @dottechdomains: An identity for builders at their core: go.tech/thegeneralistnl @ahrefs Brand Radar: Find your brand in AI results: ahrefs.com/generalist @withpersona: Trusted identity verification for any use case: withpersona.com/generalist






