Three vehicles, each one larger and more capable than the last. Mk 0 proved the design-build-test approach, Mk 1 flew, and Mk 2.1 expands the flight envelope even further. When we talk about iterative development, we actually mean it. We’ve already made three iterations in three years — and somehow our team moves even faster with each build.

ICYMI: Quarterhorse Mk 2.1 is airborne. Nine months after flying our last aircraft, we already built and flew another — proving how fast this team can build, test, and fly high-speed aircraft. The work has just begun. With first flight complete, the campaign continues toward supersonic. Stay tuned.

Live from New Mexico...it’s the Hermeus Podcast: Spaceport Edition. Our CEO and President sit down outside the hangar with a few members of the broader Quarterhorse team to talk through the road to first flight for Quarterhorse 2.1. 👉 Watch here: youtu.be/v5z5Vwug0uY

Meet Quarterhorse Mk 2.1: an F-16-sized jet built to break the sound barrier. It’s the first of three jets in the Mk 2 lineup. Instead of waiting years between tests, we build and fly them in rapid succession. Real data from one flight feeds directly into the next, letting us steadily push the limits of speed and performance. Mk 2.1 will fly supersonic. Mk 2.2 will go even faster. Subsequent phases like 2.3 will continue to push toward Hermeus’ end goal of unlocking sustained ramjet-powered flight and delivering operational hypersonic capability for the United States — this decade. Step by step, this is how Hermeus builds the world’s fastest aircraft.

Quarterhorse Mk 2.1 is coming alive. ✔ F100 full thrust firing ✔ Multiple drop tests ✔ Ground vibration testing ✔ Verification of vehicle-ground systems Fast on the ground and faster in the air.

We're not just building the planes fast, we're building the infrastructure fast. Our team has stood up deployed operations at @Spaceport_NM, transforming a blank slate into a disciplined flight-test complex, including a 6,000-square-foot custom hangar for Quarterhorse Mk 2.1 that was built in less than a week.