StoryHardware
Hermeus unveils an expendable ramjet test vehicle to be air-launched from Quarterhorse at about Mach 3
Hermeus unveiled Ramjet-X, an expendable ramjet vehicle about 22 feet long that its Quarterhorse drone would carry and release at around Mach 3. The ramjet then ignites and pushes it to about Mach 4 near 100,000 feet for tens of minutes, giving researchers a repeatable way to test sensors, materials and propulsion at high speed. Integrated tests are planned for 2027.
- A ramjet has no compressor: it relies on forward speed to squeeze incoming air, so it only works once something else has got it fast.
- Today such tests usually ride a rocket booster thrown away each flight; reusing Quarterhorse as the carrier is meant to cut cost.
- Hermeus has not published a cost per flight.
- The carrier is not ready yet: Quarterhorse Mk 2.1 reached Mach 1.21 in 2026, and the Mach 3 Mk 2.3 is still being built.
- The ramjet is being tested at Hermeus's air-breathing test facility in Jacksonville, Florida.