Early concepts of the R-56 rocket included multi-modular architecture illustrated here by a scale model intended for dynamic testing. Copyright © 2000 by Anatoly Zak

The delivery routes proposed by KB Yuzhnoe would allow the production of the R-56 rocket at the bureau's plant in Dnepropetrovsk and its delivery via waterways to any of three Soviet launch sites. Click to enlarge: 450 x 328 pixels / 56K Copyright © 2001 by Anatoly Zak

The Dnepr River, flowing through the city of Dnepropetrovsk, would be a gateway for the shipment of the R-56 rocket from its production factory here to the launch site. Copyright © 2001 by Anatoly Zak





At the beginning of the 1960s, the Space Race between the United States and the Soviet Union spurred the emergence of the projects, which only few decades before would look like a fruit of wild imagination even to the most optimistic space enthusiasts. In the USSR, the development organizations led by Sergei Korolev, Vladimir Chelomei and Mikhail Yangel, all came up with competing proposals of gigantic rockets, which could serve both as carriers of nuclear weapons and as space boosters.

Sergei Korolev's OKB-1 proposed "N" series of launchers (from word "Nositel" or Launcher); the collective of OKB-52 led by Vladimir Chelomei pushed for "UR" family (from Universalnaya Raketa or Versatile Launcher).

In its turn, Mikhail Yangel's OKB-586 design bureau, based in the city of Dnepropetrovsk, studied a 1,200-ton rocket designated RK-100. As it was the case with Korolev's N-1 and Chelomei's UR-500, Yangel advertised his future "heavy lifter" as a space vehicle and a carrier of nuclear weapons. Although, all three rockets were clearly "overweight" for most military roles, chief designers had to "sell" their projects to the Ministry of Defense in order to insure stable funding and political support within the government. In the end, none of the three projects was adopted as a weapon. In case with RK-100, the designers considered multilevel payload section with multiple warheads.

In July 1960, OKB-586 put forward a proposal to the government to develop a rocket, which would be capable of delivering 40 tons into low Earth orbit. Such payload capacity would fill the gap between Korolev's N-1 project, aiming at the time at 75 tons into low orbit and Chelomei's UR-500, capable of launching 20 tons.

The vehicle proposed by OKB-586 received an official name R-56 and industrial designation 8K68. During a preliminary design the liftoff weight of the vehicle was increased from 1,200 tons for the RK-100 to 1,400 tons for the R-56.

The development

On May 22, 1963, Central Committee of the Communist Party and the Soviet of Ministers of the USSR issued a decree, giving go ahead to the development of the experimental project, EP, of the R-56 rocket. At the time, the developers were choosing payload capabilities of the R-56 rocket based on such potential applications as the delivery of geostationary satellites, lunar and planetary probes. The R-56 could also launch a manned circumlunar expedition and supply missions for the expeditions on the surface of the Moon.

Based on these tasks, KB Yuzhnoe came up with following payload capabilities for the R-56 vehicle:

Destination Payload
200-kilometer circular orbit with inclination 49 degrees
46.1 tons
200-kilometer circular polar orbit (inclination 90 degrees)
40.0 tons
500-kilometer circular orbit with inclination 49 degrees
25.0 tons
500-kilometer circular polar orbit (inclination 90 degrees)
21.0 tons
Geostationary equatorial orbit (inclination 0 degrees)
6.5 tons
Trajectory toward the Moon
12.6 tons
Lunar orbit
7.0 tons
Soft landing on the surface of the Moon
2.8 tons
Toward Mars
8.0 tons
Martian orbit
3.0 tons
Martian surface
2.0 tons
Toward Venus
9.0 tons
Orbit of Venus
2.0 tons
Surface of Venus
1.5 tons
Trajectory perpendicular to the ecliptics (Distance: 10 million kilometers)
11.0 tons
Trajectory perpendicular to the ecliptics (Distance: 20 million kilometers)
8.7 tons
Trajectory perpendicular to the ecliptics (Distance: 50 million kilometers)
1.6 tons

In the course of the conceptual design of the R-56 vehicle, KB Yuzhnoe studied three different configurations for the prospective vehicle:

  • Four-module configuration, where each module would have a diameter of 3,8 meters -- the biggest size allowing the transportation of the individual boosters by rail;
  • Seven-module configuration, where each module would have a diameter of 3 meters -- the same as in R-36 missile, already developed by KB Yuzhnoe;
  • One-module configuration, with the diameter of the booster stages of 6,5 meters -- which would require the transportation of the vehicle via waterways;

KB Yuzhnoe ultimately selected the latter configuration, despite the need for considerable upgrade of the production facilities in Dnepropetrovsk and the development of the new means of delivery of the rocket's stages from the manufacturer to the launch sites.

The decision to develop the R-56 as a one-module booster was based on the results of a comparative analysis conducted at KB Yuzhnoe in cooperation with its subcontractors:

One-module Four-module Seven-module
Relative reliability
Relative launch readiness
Relative development cost
Relative cost of construction and support hardware
Relative cost of launch facilities
Relative cost of individual rocket

KB Yuzhnoe attributed lower cost of the development of the one-module configuration to the lower labor intensity during the construction of the rocket and to the possibility of "recycling" the dynamic configuration developed in the course of R-16 and R-36 programs. (Both rockets had a single booster stage.) Lower cost of the launch facilities and less processing work on the launch complex also would contribute to the lower cost of the one-module configuration.

R-56 technical description

In its final configuration the R-56 was designed as a two-stage vehicle delivering up 46 tons of payload to the initial low orbit. Two upper stages would be used for additional maneuvers to reach higher orbits or the escape velocity.

The first stage was equipped with 16 engines designated 11D43 and developed at OKB-456. Four of the engines are equipped with steering mechanism, allowing to control the rocket in flight. The autonomous flight control system developed at OKB-692 and NII-944 was designed to compensate for the loss of a single main engine and would allow to launch the rocket in any direction from non-movable launch complex. The aerodynamic air pressure during the launch is used to pressurize the oxidizer tank on the first stage.

The second stage was equipped with a single 11D44 engine (the modification of the first-stage engine) and a four-chamber steering engine.

The first and second stages separate after main engine cutoff on the first stage and the ignition of the steering engine of the second stage and solid-fuel separation motors on the first stage.

The orbital stage was equipped with a one-chamber main engine and a four-chamber steering engine, allowing the ignition in weightlessness. Gas generators are employed to pressurize the fuel tanks on the first, second and orbital stages.

The space stage is equipped with a single engine capable of four ignitions. A system of tanks carries pressurization gas for the propellant tanks.

A special emergency escape system, including solid-fuel motors and a parachute system was designed to retrieve the spacecraft during a failed launch.

Launch operations

In the course of the R-56 project, developers considered launching the vehicle from all three major Soviet launch sites: Kapustin Yar, Baikonur, and Plesetsk. A fully assembled rocket could be transported to any of the launch sites via waterways by the ST-600 self-propelled barge. A giant MAZ-537 trucks, used to transport all major Soviet ICBMs, would be used to carry the R-56 over land portion of the trip to the launch site.

Delivery distances from manufacturer to launch site:

Launch Site
Total distance
Distance over land
Kapustin Yar
2,030 kilometers
30 kilometers
4,270 kilometers
1,200 kilometers
6,200 kilometers
100 kilometers

The launch complex for the R-56 rocket would have two pads serviced by a single access tower, shuttling between the pads over two railway lines. Upon arrival to the launch complex, the rocket would be installed into vertical position and then integrated with its payload. During the launch the engine exhaust would be directed into a single flame duct. (98)

Cancellation of the project

In 1964, as the Soviet government gave go ahead to the development of the N1 and the UR-500 rocket, the R-56 program was canceled. Two and a half decades later Vasily Mishin, the leader of the Soviet lunar program, revealed the existence of the R-56 project. (36)