R-7 Semyorka

Development

The R-7 grew out of the Soviet programme to acquire a means of delivering nuclear weapons across intercontinental distances. Design work began at OKB-1 in 1953 with a requirement for a launch mass of 170 to 200 tons, a range of 8,500 km and a 3,000 kg warhead. When the warhead mass was raised to 5.5-6 tons late in 1953, the design had to be substantially revised. On 20 May 1954 the USSR Council of Ministers approved development of the R-7, and a new test site in Kazakhstan, later the Baikonur Cosmodrome, was established for the trials. Instead of a free-standing missile on a pad, the rocket was suspended in trusses that carried both its weight and wind loads.

Flight testing

The first test flight on 15 May 1957 failed after a booster fire, and the launch of 12 July 1957 was lost to a control failure. On 21 August 1957 the rocket completed its flight plan for the first time, but the warhead broke up during reentry. On 27 August TASS announced the successful test of a long-range multistage rocket.

Into orbit

The R-7 found its real use as a launch vehicle. On 4 October 1957 an R-7-based launcher put Sputnik 1, the first artificial satellite, into orbit, and the Luna, Molniya, Vostok, Voskhod and Soyuz families followed.

Deployment and retirement

The first R-7 unit went on alert duty at Plesetsk on 15 December 1959, and the missile formally entered service on 20 January 1960. As a weapon, however, the R-7 demanded about 20 hours of preparation, could not be kept fuelled for long, and was too large to hide. The fifty launch pads at first planned shrank to a handful, and mass deployment fell to the R-16. The R-7 and R-7A were retired by mid-1968, yet modernised versions still fly.

Assessment

The R-7 was close to a failure as a weapons system, but as a launch vehicle it became the most-launched rocket family in the world. Derivatives have carried most crews and cargo to the International Space Station, reaching over 2,000 flights by 2026.