Universal Rocket

The Universal Rocket or UR family of missiles and carrier rockets is a Russian, previously Soviet rocket family. Intended to allow the same technology to be used in all Soviet rockets, the UR is produced by the Khrunichev State Research and Production Space Centre. Several variants were originally planned, of which only three flew, and only two of which entered service. In addition, the cancelled UR-500 ICBM formed the basis for the Proton carrier rocket.

The UR-100 and its variants were the standard small ICBM of the Soviet Union during the Cold War. The Strela and Rokot carrier rockets are based on it.

The UR-200 was intended to be a larger ICBM, which could also be used as a carrier rocket. Nine test flights were made between 4 November 1963, and 20 October 1964, before the programme was cancelled in favor of Mikhail Yangel's R-36 missile and Tsyklon carrier rocket derivative.

The UR-500 was designed to be a very large ICBM, with the throw-weight necessary to deliver the 100 megaton Tsar Bomba warhead. The programme was cancelled after two flights, but with the addition of a third stage, the rocket was re-used as the Proton carrier rocket, which is still in service as of 2016.

The UR-700 was Vladimir Chelomei's heavy-lift entry for the Soviet moonshot. It was meant to carry cosmonauts to the Moon on a direct ascent mission in the LK-1 lunar craft. Sergei Korolyov's N1 booster and Soyuz 7K-L3 / LK Lander were chosen instead for the mission, and it never left the drawing board.

...
Wikipedia