✈️ Full Specifications
| Designation | Halcyon |
| Manufacturer | Hermeus |
| Country | 🇺🇸 United States |
| First Flight | 2032 |
| Crew | 2 |
| Length | 30.0 m (98.4 ft) |
| Max Speed (Mach) | 5 |
| Max Speed | 6,174 km/h |
| Service Ceiling | 30,000 m (98,430 ft) |
| Range | 7,400 km (4,595 mi) |
| Engine | Chimera TBCC (Turbojet + Ramjet) |
Overview
Hermeus is developing Halcyon, a Mach 5 hypersonic passenger aircraft that could fly New York to London in 90 minutes. Backed by the US Air Force and major investors, Hermeus is taking a radically fast approach to building the future of hypersonic travel.
Design & Development
Hermeus’ key innovation is their Chimera engine—a turbine-based combined cycle (TBCC) powerplant that integrates a conventional turbojet with a ramjet. The engine seamlessly transitions from turbojet mode (takeoff through Mach 3) to ramjet mode (Mach 3 to Mach 5+). In September 2020, Hermeus successfully tested Chimera, demonstrating Mach 5 capability on the ground.
Development Path
- Quarterhorse: Unmanned Mach 5+ demonstrator (first flight expected mid-2020s)
- Darkhorse: Larger unmanned platform for DoD missions
- Halcyon: Full-size Mach 5 passenger aircraft (20 passengers, operational 2030s)
Status
Hermeus has secured over 00M in funding including USAF contracts. The Quarterhorse demonstrator is under construction. If successful, Halcyon would revolutionize global travel—any two cities on Earth within 2 hours.
Frequently Asked Questions
How fast will the Hermeus Halcyon be?
The Halcyon is designed for Mach 5.0+ using the Chimera combined-cycle turbine-ramjet engine.
What is a combined-cycle engine?
Hermeus’s Chimera combines a turbojet (takeoff to Mach 3) with a ramjet (Mach 3 to 5+) in one package.
Has the Halcyon been built?
Not yet. The Quarterhorse unmanned demonstrator has been tested. Hermeus has USAF contracts.
What will the Halcyon be used for?
Military ISR and executive transport.