Hermeus Quarterhorse Mk 2.1 reaches Mach 1.21 on its second flight

Hermeus/Quarterhorse

Hermeus' Quarterhorse Mk 2.1 achieved supersonic flight, reaching Mach 1.21 over White Sands Missile Range on its second flight. The milestone came less than three months after the aircraft's first flight and 364 days after Mk 1's maiden flight, demonstrating rapid iteration in hypersonic development.

• Mach 1.21 reached on second flight from Spaceport America.
• Less than three months between first and supersonic flight.
• 364 days from Mk 1 maiden flight to Mk 2.1 supersonic.
• Tested in White Sands Missile Range airspace.