Pioner Credit - © Mark Wade

Mobile solid propellant intermediate range multiple warhead ballistic missile. Seen as an enormous threat to NATO. 405 launchers deployed by 1987 when the missile was banned by the INF Treaty.

Manufacturer: MITT. Launches: 7. Success Rate: 100.00%. First Launch Date: 1974-09-21. Last Launch Date: 1985-06-18. Launch data is: incomplete. Apogee: 500 km (310 mi). Liftoff Thrust: 0 N ( lbf). Total Mass: 37,000 kg (81,000 lb). Core Diameter: 1.79 m (5.87 ft). Total Length: 16.50 m (54.10 ft). Maximum range: 5,000 km (3,100 mi). Number Alternate Warheads: 1. Total Number Built: 765.

15Zh45. IOC: 1976. Other Designations: RSD-10. Department of Defence Designation: SS-20 Mod 1 and Mod 2. ASCC Reporting Name: Saber. Article Number: 15Zh45. Launch System: Pioner. Complex: 15Zh45.

The missile was given a different DOD mod designation according to the number of warheads - Mod 1 for the single warhead version, Mod 2 for the triple warhead version.

In the 1970's the late 1960's the Soviet Union found itself threatened by intermediate-range ballistic missiles stationed around its borders by states other than the 'main adversary'. China had developed their Dun-1 (DF-2) IRBM based on drawings and a single example provided to them before the break with Moscow. This missile was accepted by the Chinese military in 1970. In 1971 tests began of their Dun-2 (DF-3), with a range of 4000 km, capable of striking any target in Europe. The French deployed their 3,000 km range SSBS S-1 IRBM in 1971 as well. To counter this threat the Soviet Union had only R-12 and R-14 missiles deployed to fixed locations. A mobile, solid-propellant, multiple-warhead IRBM that could not be taken out by an enemy first strike was needed. The RT-15 and RT-20P mobile IRBM's had been developed in the 1960's but neither was deployed due to operational shortcomings.

Nadiradze had begun basic research on such a missile in 1971. An official decree of 28 April 1973 authorised full scale development. A series of twenty flight tests were conducted at Kapustin Yar from 21 September 1974 to 9 January 1976 and were completely successful. The system was accepted by the military on 11 March 1976. The Votkinsk Factory produced both the pre-production missiles from 1973 and the production missiles from 1976. The first field regiment was deployed to Petrikov in Belorus in August 1976. Further regiements of 9 launchers each were deployed to Barnaul, Irkutsk, and Kansk. The appearance of what was dubbed the 'SS-20' created huge consternation within the United States, as opposed to the 'secondary enemies' at whom they were targeted. They eventually led to the counter-deployment of American Pershing 2's and Gryphon cruise missiles to Europe, huge anti-American demonstrations in Western Europe, and finally, on the eve of the disintegration of the 'Evil Empire', the Intermediate Nuclear Forces Treaty, which eliminated all such weapons from Europe.

The missile was designed on the strict rule of 'no liquids'. The composite solid propellant motors for all three stages were designed and built by Boris Zhukov at LNPO Soyuz. The launcher was by Valerian Sobolev at PO Barrikada and the inertial navigation system and digital control computer were by Pilyugin and Vlaidimir Lapygin at NII AP. Composite materials for the launch container were by Viktor Protasov at TsNII Spetsmash. All of this new technology gave the missile a two-minute reaction time from the order to launch to the moment it was popped out of its container by a cold-gas charge. The multiple warheads were mounted externally canted on the dispenser bus; there was no fairing. The re-entry vehicles were separated and sent on different trajectories using programmable solid propellant charges.

The missile body was built of glass-fibre wound composite, reinforced by titanium in the booster section, with use of magnesium alloy elsewhere. The first stage would burn to depletion, while the last stage was equipped with a thrust termination system for cut-off on the desired trajectory. Stage 1 used 'grid' aerodynamic stabilisers, while stage 2 was controlled by gas injected into the nozzle for pitch and yaw, and a jet powered by a separate gas generator for roll. The missile was sealed in its container as a 'certified round' for the duration of its operationl life. The launcher had a mass of 40.25 tonnes unloaded, or 83.95 tonnes with the rocket in its container. Special open shelters were built for stationing and to protect crew during maintenance of the launcher and external equipment.

In parallel with the Pioner the Temp-2S mobile ICBM was built and deployed in contravention of the SALT-2 Treaty. This the same warhead dispenser bus but used larger and wider motors in the upper stages and had other detailed differences in systems. However apparently the same launcher was used, which led the Soviets to attempt to deceive the Americans as to its existence.