Why Replacing the Concorde Has Been So Hard

TL;DR

Hypersonic flight remains unachievable for passengers because no engine works efficiently at both takeoff speeds and Mach 5+.

Key Points

• 1.At hypersonic speeds (Mach 5+), air molecules break apart, creating temperatures up to 2000°C that require extreme thermal shielding just to keep passengers alive
• 2.Engines designed for above Mach 5 don't function below Mach 1, meaning a commercial plane would need a costly dual-mode engine system that doesn't yet exist
• 3.Wings become structural liabilities at hypersonic speeds — reinforcing them adds weight, and the few successful hypersonic vehicles (like the X-43A) had no wings, landing gear, or passengers, and intentionally crashed into the Pacific after one flight
• 4.The only crewed hypersonic flight on record was the 1967 X-15, which reached Mach 6.7 only after being dropped from a carrier plane at altitude — no takeoff or landing involved
• 5.China's 2021 Gobi Desert test of a broad, cone-shaped prototype reached Mach 6.5 using an unconventional design that redirects high-pressure air over the body and into top-mounted wings for lift — a potential breakthrough in passenger-friendly hypersonic design