Startup Hermeus is developing hypersonic propulsion system for their Quarterhorse and Darkhorse vehicles. This could be achieving mach 5 speeds in 2026 to 2027. Quarterhorse Development Timeline: Mk 1: The first flyable version of Quarterhorse, Mk 1, is set for flight tests later in 2024. These tests will focus on high-speed takeoffs and landings Mk ... Read more