Missile RSD-10 Pioneer (SS-20 Saber)

Conceived to replace the R-12 Dvina and R-14 Chusovaya missiles fielded in the USSR and Warsaw Pact states from 1958 and 1961, the RSD-10 Pioneer entered the development stage in 1966, with a design concept approved in 1968. It was derived from the RT-21 Temp 2S intercontinental ballistic missile programme, reusing its two solid-fuel, fiberglass-clad stages, and was consequently also designated RT-21M Pioneer. Flight testing began in 1974. NATO assigned the reporting name SS-20 Saber; the GRAU index was 15Zh45.

The Pioneer was the first Soviet ballistic missile to use solid propellant rather than storable liquids, removing the hours of fuelling operations previously required before launch and allowing firing shortly after the order was received. The initial configuration carried a single 1-megaton warhead weighing 1.6 tonnes. Later variants carried one, two, and from 1980 three 150-kiloton MIRV warheads (Pioneer UTTH). Circular error probable was reduced from 550 metres to between 150 and 450 metres across the production run. The missile was 16.5 metres long, 1.8 metres in diameter and weighed 37.1 tonnes, and was carried on the MAZ-547A/MAZ-7916 transporter erector launcher, built in the Belarusian SSR and originally designed for the RT-21 Temp 2S.

Deployment began on 11 March 1976 under the Strategic Missile Forces, with the first units becoming operational that August. Fielding continued until 1986, by which point 48 launch sites, including one at Pavschino, had been equipped with 435 missiles. Soviet units included the 23rd Guards Rocket Division at Kansk, Krasnoyarsk Krai, which operated the type from approximately 1983 to 1988. The Soviet Union was the sole operator.

Testing of the modernised Pioneer-UTTKh (15Zh53) began at the Kapustin Yar test site on 10 August 1979 and continued until 14 August 1980. The variant was deployed on 17 December 1980 and designated SS-20 Mod 3 by NATO, later redesignated SS-28 Saber 2. It retained the propulsion system of earlier versions but incorporated a revised command structure and instrumentation-service unit, improving CEP from 550 to 450 metres, increasing maximum range by 10 percent, and enlarging the footprint covered by the warheads.

The system gave Soviet forces an in-theatre selective targeting capability against NATO bases and installations with minimal warning time, including NATO's tactical nuclear forces. Its deployment prompted NATO's Double-Track Decision of 1979, under which US Pershing II ballistic missiles and BGM-109G Gryphon ground-launched cruise missiles were fielded in Western Europe.

A total of 654 missiles were built. All of these and the 499 associated mobile launchers were destroyed by May 1991 under the terms of the 1987 Intermediate-Range Nuclear Forces Treaty, which removed the RSD-10 from service. Fifteen RSD-10 airframes were preserved, alongside eight BGM-109G and seven Pershing II missiles. Surviving examples are displayed at the National Museum of the History of Ukraine in the Second World War, at the Ukraine Air Force Museum in Vinnytsia, and at the Smithsonian National Air and Space Museum in Washington, D.C.

North Korea obtained an unspecified number of demilitarised RSD-10 transporter erector launchers from Russia or Belarus for use with the BM-25 Musudan missile.