Why the US-China space race could come down to a thin metal cap

In the high‑stakes space race between the United States and China, the decisive advantage could come down to a metal cap that few outside the industry have ever heard of: the propellant tank dome.

An ellipsoidal bulkhead several metres wide but only millimetres thick, the dome must withstand extreme internal pressures, vibration and shock. The rounded, capsule-like end cap is also very difficult to mass-produce.

Whichever country can make these components faster, cheaper and more reliably will have an advantage in building the large fleets of reusable rockets needed for the future space economy.

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Now, China is signalling that it may have found not one but two ways to break the bottleneck.

The flight showcased a dome made with a welding method benchmarked against SpaceX’s Falcon series but potentially faster off the production line.

At the same time, Chinese researchers have unveiled a revolutionary “cold forming” technique that can shape a complete, seamless dome in a few hours rather than a week – an advance that could tilt the balance of the US-China space race in the years ahead.