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.
- UR-100 1
- UR-200 2
- UR-500 3
- UR-700 4
- UR-900 5
- Further reading 6
- See also 7
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 2015.
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.
Superficially, the UR-700 was of the well-known design of Soviet launchers with a central core stack and lateral strap-on boosters. But one distinguishing feature was that the engines of the first stage were cross-fed with fuel and oxidizer from the tanks of the strap-on boosters during the initial flight phase. This meant that when the boosters were spent and jettisoned, the central stack still flew with full tanks, thus reducing dead weight and increasing a possible payload.
The UR-900 was the ultimate Universal Rocket application, an ultra-heavy-lift booster for crewed expeditions to other planets. As such it remained a paper project.