RT-20P (8K99) missile


The RT-20P (8K99) missile

Known specifications of the RT-20P missile:

Number of stages
Length of the vehicle

17.48 - 17.8 meters

1.6 meters
Weight (fueled)
30.0 - 30.2 tons (30.9 tons)
Weight with container
38.8 tons (with light warhead)
Oxidizer Nitrogen tetroxide
First launch 1967 October
Launch sites Plesetsk

Flight range:

  • 7,000 - 8,000 km with a heavy warhead
  • 11,000 km with a light warhead
Warhead mass:
545 - 1,410 kg

With the RT-20 project, KB Yuzhnoe in Dnepropetrovsk made one of the first attempts in the USSR to develop a mobile ICBM. KB Yuzhnoe conducted preliminary study, NIR, within the project designated RT-20P from 1961 to 1962. In 1963, the project entered development stage, OKR. The main requirement of the program was the development of the mobile system not exceeding 30 tons in weight. In the proposed configuration, the first stage of the rocket burned solid fuel, the second liquid-fuel. It would be deployed on a crawler based on the T-10M tank.

The preliminary design of the RT-20P system was completed in December 1964 and the project was approved by the government in 1965.

Test firings of the solid-fuel 15D15 engines started in April 1965 at the test bench of NII-58 research institute in the town of Krasnoarmeisk, Moscow Region.

Test launches started in October 1967 in Plesetsk. Large percentage of launches was apprently unsuccesful and, in addition, Soviet Strategic Rocket Forces, RVSN, refused using mobile complex employing liquid fuel. As a result, on October 6, 1969, the government officially shut down the program.


Article and photography by Anatoly Zak

Last update: February 28, 2020

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Final assembly of the 8K99 missile. Copyright © 2001 Anatoly Zak

The 8K99 ballistic missile for the RT-20P complex. Shown without aerodynamic fairing on the tip of the warhead. 16 windows with the total area of 1.2 meters between the stages allow the ignition of the second stage before the separation from the first stage. Copyright © 2001 Anatoly Zak

A monument to RT-20P missile. Copyright © 2017 Anatoly Zak