Hermeus Develops Ramjet-X to Cut High-Mach Flight Test Costs
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Los Angeles – September 13, 2026 -- Hermeus is developing Ramjet-X, an expendable, ramjet-powered test vehicle designed to be launched from its reusable Quarterhorse aircraft, aiming to make high-Mach airbreathing flight testing cheaper and more repeatable.
Quarterhorse aircraft eliminates need for costly disposable boosters
Ramjet engines require substantial initial speed before they can operate, historically forcing test programs to rely on large, expensive, single-use boosters. Hermeus instead uses its reusable Quarterhorse aircraft to accelerate Ramjet-X to the required speed and altitude before release, after which the vehicle enters ramjet-powered flight while Quarterhorse returns for subsequent missions.