The Mammoth Book of Space Exploration and Disasters

The Soviets were aware that their former Allies had significant advantages in long-range bomber aircraft, so to counter this they were interested in developing long-range ballistic missiles. The Soviet leader, Joseph Stalin, imagined a more powerful version of the V-2, armed with a nuclear warhead. They set up a German engineering team under Helmut Grottrup at a base north-west of Moscow where they were to develop their own intercontinental ballistic missiles (ICBMs).

The Russians had their own tradition of the science and theory of rocketry. Their pioneer was Konstantin Tsiolkovsky. Tsiolkovsky had written a theoretical article called “Exploration of Cosmic Space with Reactive Devices” in 1898 but it was not published until 1903. In it he suggested the use of liquid propellants for rockets in order to achieve greater range and went on to state that the speed and range of a rocket were limited by the exhaust velocity of escaping gases. A substantial part of the article was devoted to a detailed description of the mechanics of putting a satellite into orbit.

The Soviets’ chief rocket designer was a Russian, Sergei Korolev; like von Braun, Korolev had served an “apprenticeship” in amateur and semi-official rocket groups. By the late 1940s the Soviets had learnt all they could from their German captives and had solved the overheating problems which were inherent in high-energy rockets, having to do this within the limits of Soviet metallurgy. They did this by creating an engine with four small, thickly walled combustion chambers – the RD-107 engine which was fuelled by kerosene and liquid oxygen and produced 225,000 lb of thrust. It was capable of being the basic element of either an ICBM or the booster or launcher of a spacecraft.

The key to a long-distance missile lay in Tsiolkovsky’s concept of multiple stages: the first, heavy stage enabled the rocket to break free from the earth’s gravity. The lighter upper stages would accelerate it to the speeds necessary for intercontinental ballistic trajectory or orbital flight. Ideally the upper stage engines should be lighter with a higher thrust-to-weight ratio, but lighter upper stages were beyond Soviet technology. Korolev came up with a compromise which was within the Soviets’ capability.