Quarterhorse

Overview

An iterative program of unmanned, remotely piloted test aircraft designed to unlock high-speed flight one step at a time. Hermeus says the Quarterhorse program spans four aircraft, each purpose-built to validate a specific technical challenge and feed the next build.

Mk 1 flew at Edwards AFB in May 2025. Mk 2.1, roughly F-16-sized and powered by a Pratt & Whitney F100, flew in February 2026 and on its third flight from Spaceport America hit Mach 1.21, becoming the first privately-developed unmanned supersonic jet. Hermeus says Mk 2.2 and Mk 2.3 are already in build.

Key Specs