Missile researcher Fabien Hints argues that the Russian 3M22 Zircon is likely a semi‑ballistic missile with a solid‑fuel rocket, rather than a hypersonic cruise missile using a scramjet. He cites debris from Ukrainian battlefields, launch images and Russian patent documents, which he says lack evidence of an air‑breathing engine and instead match solid‑propellant rocket components. Ukrainian estimates suggest Zircon travels at about Mach 5.5 for most of its flight, accelerates to Mach 7.5 before the terminal phase, and impacts at roughly Mach 4.5. If correct, the weapon follows a high‑altitude glide trajectory with limited maneuvering, making interception difficult despite not being a true hypersonic cruise. Experts note that even as a semi‑ballistic system, Zircon remains a serious threat due to its high speed and terminal maneuverability.