The de Havilland Propellers Blue Streak was a British Intermediate-range ballistic missile (IRBM), and later the first stage of the Europa satellite launch vehicle.

[4] The project was intended to maintain an independent British nuclear deterrent, replacing the V bomber fleet which would become obsolete by 1965.

This led to the formation of the European Launcher Development Organisation (ELDO), with Blue Streak used as the first stage of a carrier rocket named Europa.

[citation needed] Post-war Britain's nuclear weapons armament was initially based on free-fall bombs delivered by the V bomber force.

The proposal was accepted as part of the Wilson-Sandys Agreement of August 1954, which provided for collaboration, exchange of information, and mutual planning of development programmes.

The de Havilland Propellers company won the contract to build the missile, which was to be powered by an uprated liquid-fuelled Rocketdyne S-3D engine, developed by Rolls-Royce, called RZ.2.

This configuration, however, put considerable pressure on the autopilot which had to cope with the problem of a vehicle whose weight was diminishing rapidly and that was steered by large engines whose thrust remained more or less constant.

Subcontractors included the Sperry Gyroscope Company who produced the missile guidance system whilst the nuclear warhead was designed by the Atomic Weapons Research Establishment at Aldermaston.

These would have been designed to withstand a one megaton blast at a distance of one-half mile (800 m) and were a British innovation, subsequently exported to the United States.

RAF Spadeadam in Cumberland (now Cumbria) was the only site where construction was started on a full scale underground launcher, although test borings were undertaken at a number of other locations.

Its detractors in the civil service claimed that the programme was crawling along when compared with the speed of development in the US and the Soviet Union.

Admiral of the Fleet Lord Mountbatten had spent considerable effort arguing that the project should be cancelled at once in favour of the Navy being armed with nuclear weapons, capable of pre-emptive strike.

considered the cancellation of Blue Streak to be not only a blow to British military-industrial efforts, but also to Commonwealth ally Australia, which had its own vested interest[clarification needed] in the project.

The British military transferred its hopes for a strategic nuclear delivery system to the Anglo-American Skybolt missile, before the project's cancellation by the United States as its ICBM programme reached maturity.

As the government of John Diefenbaker in Canada was already spending more money than publicly acknowledged on Alouette and Australia was not interested in the project, these two countries were unwilling to contribute.

[9] The UK instead proposed a collaboration with other European countries to build a three-stage launcher capable of placing a one-ton payload into low Earth orbit.

The European Launcher Development Organisation consisted of Belgium, Britain, France, West Germany, Italy and the Netherlands, with Australia as an associate member.

Italy worked on the satellite project, the Netherlands and Belgium concentrated on tracking and telemetry systems and Australia supplied the launch site.

Aside from Black Prince, a range of other proposals was made between 1959 and 1972 for a carrier rocket based on Blue Streak,[11] but none of these were ever built in full and today only exist in design.

[13] Following the cancellation of the Blue Streak project some of the remaining rockets were preserved at: A section of the propulsion bay, engines and equipment can be found at the Solway Aviation Museum, Carlisle Lake District Airport.

Blue Streak enthusiast Robin Joseph from the United Kingdom has a collection of parts including start systems and combustion chambers amongst other things.