Prospero

On 28 October 1971, at Launch Area 5B in the South Australian desert at Woomera, a slender British rocket called Black Arrow lifted off on a flame that was almost invisible. The strange part was that the program it belonged to was already dead. The British government had cancelled Black Arrow in July 1971, three months earlier, but this final vehicle, R3, was already built and shipped, so the launch was allowed to proceed. The engineers on the range were sending up a satellite for a country that had just decided it no longer wanted its own rockets.

Black Arrow was a quiet triumph of frugal engineering by the Royal Aircraft Establishment and its Isle of Wight contractors. It burned kerosene with high-test hydrogen peroxide, a combination that produced a clean, nearly smokeless exhaust. Its payload, a 66-kilogram experimental satellite designated X3, carried solar cells, thermal-surface materials, and instruments meant to prove technologies for future communications satellites. Forty minutes after liftoff, tracking confirmed it was safely in a 531 by 1,403 kilometre orbit inclined at 82 degrees.

Once in orbit the satellite received its name: Prospero, after the magician in Shakespeare's The Tempest who renounces his magic at the play's end. For a nation surrendering its launch capability, the choice was pointed. The United Kingdom had become the sixth country to orbit a satellite on its own rocket, and the first and only one to then walk away from that capability. No Black Arrow ever flew again; the backup vehicle, R4, hangs today in London's Science Museum.

Prospero itself outlived the program by decades. Its experiments operated until 1973, and ground controllers continued to contact the old satellite annually until 1996, when the tracking station at Lasham was decommissioned. It is still up there, circling Earth on every pass as a small, persistent reminder of the road not taken, and British engineers have since floated proposals to retrieve it as a national heirloom.