London to Sydney currently takes about 22 hours, assuming you don’t get stuck in Heathrow security. The UK is backing a project that could cut that to three.
The Invictus program, a European Space Agency initiative launched in July 2025, is developing a hypersonic test vehicle capable of reaching Mach 5, which translates to speeds exceeding 3,800 mph. Led by UK-based Frazer-Nash Consultancy, the project has a target of achieving a working flight test vehicle by early 2031. Two potential UK test sites have already been shortlisted: Spaceport Cornwall and Machrihanish in Scotland.
From the ashes of Reaction Engines
Here’s the thing about Invictus: it’s essentially a resurrection story. The project builds directly on pre-cooler engine technology pioneered by Reaction Engines Ltd, a British company that entered administration in late 2024. Five former Reaction Engines engineers have joined Frazer-Nash to work on Invictus, bringing with them expertise that took years to develop and can’t be replicated from a textbook.
The technology lineage runs deep. Reaction Engines spent years developing the SABRE engine, a hybrid air-breathing rocket engine designed for a concept vehicle called Skylon. That work itself traced back to HOTOL, a horizontal takeoff and landing spaceplane concept from 1982. Invictus represents the latest chapter in a research thread that spans more than four decades of British aerospace ambition.
