Monday, 11 November 2019

That Time When Britain Had Its Own Rocket

Black Arrow at Woomera
For a country as technological advanced as Great Britain, it sounds almost implausible when you say that the British do not have a space program. But fifty years ago, they almost did only to have the parliament throw it away, becoming the first, and so far, the only nation to develop satellite launch capability and then abandon it.
The Black Arrow program was initiated in 1964 as the next logical step after the successful Black Knight program, which was a research ballistic missile originally developed to test and verify the design of a re-entry vehicle for the medium-range ballistic missile Blue Streak. Blue Streak was cancelled, but Black Knight continued development becoming the United Kingdom's first indigenous expendable launch project.
Black Knight was a single stage ballistic missile, capable of achieving an altitude of 800 kilometers, but it couldn’t place satellites into orbit. Britain's first satellite, Ariel 1, rode on top of a US rocket. Black Arrow was intended to be “technical demonstrator”, to show that a small satellite launcher could be built using the kerosene/high-test peroxide(HTP) technology developed for Black Knight.
The combination of kerosene and hydrogen peroxide makes an amazing rocket fuel. The hydrogen peroxide molecule has two atoms of hydrogen and two atoms of oxygen. It decomposes easily in the presence of a catalyst, such as a silver plated nickel gauze, to form water and oxygen. The main fuel is kerosene that is pumped into the combustion chamber in a finely divided spray, which is ignited in the presence of oxygen derived from the breakdown of hydrogen peroxide. The result is a clean, smokeless exhaust.
Black Arrow at Woomera
A comically simple launchpad at Woomera.
Kerosene/hydrogen peroxide engines, also called Gamma engines, were simpler and more reliable to construct than other liquid propellant engines, that require oxygen to be stored in cryogenically frozen tanks, which adds to the complexity. Gamma engines had an impeccable service record rarely seen in rocket engine. Of the 22 Black Knight and 4 Black Arrow launchers, involving 128 Gamma engines, there were no engine failures.
Originally, the plan was to put a satellite called “Puck,” after the character in Shakespeare's A Midsummer Night’s Dream. The satellite was designed to conduct experiments to test the technologies necessary for communication satellites, such as solar cells, telemetry and power systems. It also carried a micrometeoroid detector, to measure the presence of very small particles. The original launch date target was 1968, but because of problems in Black Arrow’s engines, the launch date was postponed. By 1969, the program had already begun to feel the pinch of budget cuts. From the proposed five launches, the program was cut to just three, which meant that an orbital attempt would have to be made on only the second mission. The first mission would consist of two live stages and a dummy payload. The next launch would orbit a simple developmental satellite. The third launch would carry a fully working satellite into orbit.
Black Arrow's engines
Black Arrow’s exhaust nozzles, at London’s Science Museum. Photo credit: Royal Aircraft Establishment
All Black Arrow launches were made from Woomera, in South Australia. The location was picked because of the low population density of the region. Launches from the British Isles were impossible because there was no area in Britain that lay far away from inhabited areas.
The first launch (R0) was a failure, and the vehicle had to be destroyed to prevent it from veering off towards inhabited areas. The failure was a major setback for the already tight Black Arrow launch schedule. The next vehicle would now have to repeat the intended mission of the first, rather than attempt a launch of the developmental satellite. The second attempt (R1) was successful and everybody breathed a collective sigh of relief as the Black Arrow program came back on course. But the next launch (R2), that was supposed to put a test satellite into orbit failed again, and the rocket crashed into the Gulf of Carpentaria.
The second failure set the Black Arrow program back by several months as engineers tried to figure out and rectify the various problems. Then, an industrial dispute at Rolls-Royce, the parent company of Bristol Siddeley, who manufactured the Gamma rocket engines, added further delay. The launch was pushed back to October 1971.
Some of stages were ready by mid-1971, and was shipped to Australia for the launch. The tragic announcement came a few days after the second stage arrived at Woomera—the House of Commons had decided to cancel the Black Arrow program, citing that it was much cheaper to use an American rocket instead. However, there was enough hardware for a final launch attempt, so permission was given to launch this flight.
Prospero, the satellite
Prospero, the satellite.
The satellite, which was originally named “Puck”, was renamed “Prospero” after the character in Shakespeare's The Tempest, who voluntarily gives up his powers. On 28 October 1971, the last Black Arrow (R3) blasted off from Woomera and placed Prospero into orbit. With this, Britain became the sixth nation in the world to successfully develop satellite launch capability, but the only one to abandon it. Prospero became Britain’s first and only satellite to be launched by an indigenously built vehicle. It still circles the earth today, with a maximum altitude (apogee) of 1,314 km and minimum altitude (perigee) of 534 kilometers, although it has long since lost power.
The launch facilities at Woomera were demolished within a year of the final flight and half of the engineers who had worked on the program were laid off. The remains of the first stage of Black Arrow R3 was recovered from the Anna Creek cattle station—an enormous cattle station in South Australia—where it had fallen and was displayed in the William Creek Memorial Park for nearly fifty years, before it was returned to the United Kingdom in early 2019. It is now on display at Penicuik, Scotland.
Black Arrow at Woomera

Remains of the first stage of the Black Arrow rocket at the Memorial Park at William Creek, South Australia. 

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