Aerospace startup Hermeus has announced the development of an expendable, ramjet-powered autonomous vehicle designated Ramjet-X. Designed to air-launch from the company's F-16-sized Quarterhorse drone, the new vehicle measures approximately 22 feet in length and 7 feet in width. Under the mothership-parasite concept, the Quarterhorse Mk 3 will carry up to two Ramjet-X vehicles under its wing pylons.
The operational concept relies on Quarterhorse releasing the Ramjet-X at a release speed of around Mach 3, providing the high initial speed necessary for the ramjet engine to initiate. Following launch, Ramjet-X is designed to climb to an altitude of around 100,000 feet and operate at speeds of around Mach 4, placing its operational regime just below the Mach 5 hypersonic threshold.
Hermeus is currently conducting ground testing of the Ramjet-X ramjet engine at its HEAT facility in Jacksonville, Florida. The company plans for integrated vehicle testing to commence in 2027. By leveraging the reusable Quarterhorse launch platform together with the smaller expendable vehicle, organizations will be able to perform high-Mach experimental flights without requiring bespoke test vehicles.
According to Hermeus, Ramjet-X will allow the contractor to offer high-Mach Flight Test as a Service (FTaaS), opening access to flight test environments that have historically been costly and difficult to reach. The platform can integrate experimental payloads, sensors, communications hardware, autonomy systems, material samples, and software. Hermeus CEO Zach Shore emphasized that high-speed flight testing is extremely expensive and that Ramjet-X lowers barriers to gathering valuable data.
Additionally, Hermeus is among the nine acknowledged vendors planning to compete for the US Air Force's Increment 2 Collaborative Combat Aircraft (CCA) programme. While most competing CCA concepts focus on subsonic capabilities, Hermeus aims to develop supersonic autonomous aircraft with long-term plans for high-speed flight technology.
