Quarterhorse MK 2.1 Achieves First Supersonic Flight There is definitely a race going on now in the supersonic and hypersonic experimental departments. Between, NASA's/Lockheed Martin's X-59 Demonstrator, BOOM Supersonic's XB-1 and Hermeus Quarterhorse program each company has been knocking off their first supersonic flights. However, Hermeus has claimed that it has been the fastest to go supersonic from founding to supersonic flight.
On May 26, 2026 Hermeus announced its Quarterhorse Mk 2.1 successfully completed its first supersonic flight, reaching a top speed of Mach 1.21. The flight was executed on just its third test flight out of Spaceport America over White Sands Missile Range air space. The achievement underscores Hermeus’ pace of iterative development in aviation. Quarterhorse Mk 2.1 flew supersonic less than three months after its first flight, and 364 days after the maiden flight of Hermeus’ first aircraft, Mk 1.
“Our customers at the Department of War are paying close attention to how fast this program is moving,” said AJ Piplica, CEO and Co-founder of Hermeus. “This flight demonstrates a pace of execution that is extremely rare in modern aviation. Our country’s ability to deliver new asymmetric military capability at scale depends on teams that can solve hard technical challenges quickly. That’s exactly what we’re proving with each test flight we conduct and each new aircraft we build at Hermeus.”
Next for the program will be the continual testing on the next iteration of the Quarterhorse which will be the Quarterhorse Mk 2.2, with Mk 2.3 soon to follow. Each aircraft in the roadmap is designed to push performance further and move quickly toward sustained high-Mach flight. For more information: Hermeus 1954 Airport Rd Atlanta, Georgia 30341 www.hermeus.com ***
