R-7 (rocket family)


The R-7 family of rockets is a series of rockets, derived from the Soviet R-7 Semyorka, the world's first ICBM. More R-7 rockets have been launched than any other family of large rockets.
When Soviet nuclear warheads became lighter, the R-7 turned out to be impractical as a ballistic missile. It was not necessary to launch such heavy payloads in a military application. The rockets became useful in the Soviet, and later, Russian space programmes with long-term development. Their purpose shifted primarily to launching satellites, probes, manned and unmanned spacecraft, and other non-threatening payloads. The R-7 family consists of both missiles and orbital carrier rockets. Derivatives include the Vostok, Voskhod and Soyuz rockets, which as of 2019 have been used for all Soviet, and later Russian human spaceflights. The type has a unique configuration where four break-away liquid-fueled engines surround a central core. The core acts as, in effect, a "second stage" after the other four engines are jettisoned. These rockets are expendable.
Later modifications were standardised around the Soyuz design. The Soyuz-2 is currently in use.
The Soyuz-FG was retired in 2019 in favour of the Soyuz-2.1a. R-7 rockets are launched from the Baikonur Cosmodrome, Plesetsk Cosmodrome, Guiana Space Centre, and the Vostochny Cosmodrome.
After the R-7/Soyuz-U and the Thor and Delta rocket families, the Kosmos launch vehicle, the best known of which is the Kosmos-3M, holds the 3rd place record for number of successful orbital launch attempts, that is, of placing a satellite in orbit.

Summary of variants

All the R-7 family rockets are listed here by date of introduction. Most of the early R-7 variants have been retired. Active versions are shown in green.

Korolev Cross

The Korolev Cross is a visual phenomenon observed in the smoke plumes of the R-7 series rockets during separation of the four liquid-fueled booster rockets attached to the core stage. As the boosters fall away from the rocket, they pitch over symmetrically due to aerodynamic forces acting upon them, forming a cross-like shape behind the rocket. The effect is named after Sergey Korolev; the designer of the R-7 rocket. When the rocket is launched into clear skies, the effect can be seen from the ground at the launch site.