Doug Millard discusses the West's feelings about Russia and the possibility of nuclear attack during the Cold War (2:04 min)

In 1958 Britain was two years into a programme called Blue Streak. Blue Streak was an intermediate-range ballistic missile capable of delivering a one-megaton nuclear warhead to its target. It would be launched from underground silos in the south and east of England and climb above the Earth's atmosphere. Then, it would re-enter the atmosphere in a ballistic trajectory to strike strategic targets in the Soviet Union. Blue Streak was not intended as a first-strike weapon--it would only be launched in response to an incoming Soviet missile strike.

Black Knight
Scientists trying to predict the behaviour of Blue Streak's warhead as it re-entered the atmosphere had needed an intensive research programme. They knew little of the warhead's likely performance in flight. The research had had to determine the type of material the warhead should be made out of and what shape it should be. To enable this work, Britain had developed a test missile called Black Knight. Researchers launched Black Knight vehicles at steep angles with test re-entry heads of different shapes and materials. As the heads re-entered the atmosphere, the researchers monitored their behaviour and used the information to design the operational warhead for Blue Streak.

Science Museum, London/ Science & Society Picture Library

Black Knight vehicle (1.8 model), c.1957. Black Knight was originally designed to accelerate a re-entry head back into the atmosphere at speeds of about 3.6 kilometres per second. This model was made at the Royal Aircraft Establishment.

Black Knight was a far smaller rocket vehicle than Blue Streak. It was not nearly powerful enough to launch a satellite. The same was true of Blue Streak itself, despite its greater size. But there was a way in which Britain could, in theory, use these rockets to build a satellite-launch vehicle. The idea was to combine Blue Streak and Black Knight as the first and second stages of a larger vehicle, and then add a small third stage. Britain's main defence-research centre, the Royal Aircraft Establishment (RAE), performed technical studies to see how such a Blue Streak/Black Knight combination might be built. The Macmillan government was asked questions following the launch of Sputnik 1 because Britain had the potential to adapt its missiles for spaceflight.

However, the government made no policy commitment on any aspect of space exploration until 1959. The delay frustrated those scientists, engineers, industrialists and commentators who felt that Britain should be taking a more active role in the new field of space exploration. Prime Minister Macmillan then announced that Britain would embark upon a scientific satellite programme, but he did not say what kind of vehicle would be used to launch the satellites. Britain might use a vehicle developed for the missile programme, but might also consider a collaborative effort with the US, with Britain's Commonwealth or with other countries. In reality, a US offer of its Scout vehicle to launch satellites had prompted Macmillan's space policy announcement in the first place, and by autumn 1959 plans were well advanced to take advantage of the offer. This meant that the Blue Streak/Black Knight studies remained on the drawing board. However the Macmillan government would also have been aware of developments elsewhere, which meant that Blue Streak/Black Knight was not forgotten.

Problems with Blue Streak
Blue Streak was intended as a retaliatory weapon which would only be used if the Soviet Union launched a missile attack on Britain. But the Soviet Union's forces were so vastly superior to Britain's that the damage caused by a Soviet attack would dwarf any damage that Britain's Blue Streak could inflict in retaliation. The deterrent factor of Blue Streak was built on the calculation that, if just some of the Blue Streak missiles could penetrate Soviet defences, then the Soviet Union might hesitate from launching an attack first.

However, if Blue Streak was shown to be vulnerable to such a Soviet first strike, its credibility as a retaliatory weapon would be seriously undermined. Retaining Blue Streak in these circumstances would indicate that British military policy had shifted from being defensive in nature to being offensive. This would increase the likelihood of the Soviet Union launching a pre-emptive nuclear strike to destroy Britain's offensive capability. In other words, in a worsening international situation in the run-up to war, the Soviet Union would be more likely to launch a massive pre-emptive nuclear strike on Britain if an 'offensive' Blue Streak system was retained.

By 1960, Britain's defence chiefs had concluded that Blue Streak was vulnerable. This meant that it could only be retained as an offensive weapon and, given that there were alternative US systems now available, should be cancelled. The Macmillan government therefore decided to abandon Blue Streak in April 1960. Plans were made to replace it with the United States' Skybolt missile system, but tests showed that its technology was faulty. Macmillan then had negotiations with US President John F. Kennedy, who agreed to sell Britain the Polaris submarine-launched ballistic missile system instead.