Hermeus Achieves Its First Unmanned Supersonic Flight

Hermeus has achieved its first unmanned supersonic flight, establishing Quarterhorse Mk 2.1 as the world’s fastest privately developed unmanned jet. The test, conducted at Spaceport America over White Sands Missile Range, reached Mach 1.21 on May 26, 2026, just its third flight and less than three months after the program’s inaugural selfie. Quarterhorse Mk 2.1 is powered by a Pratt & Whitney F100 engine as part of a trio of F-16‑scale aircraft designed for rapid iteration. CEO and co-founder AJ Piplica highlighted the program’s pace as a proving ground for agile defense aviation and rapid capability delivery to the Department of War. Two additional aircraft, Mk 2.2 and Mk 2.3, are in development to extend performance and speed progress.

The milestone comes amid growing Pentagon emphasis on high-speed, unmanned systems to counter near-peer competition, notably China. Hermeus argues that faster unmanned platforms can shorten response times and enable mass deployment in contested environments, while continuing its flight test program with Mk 2.1 and progressing toward higher Mach regimes.