Osa 9M33 Credit - © Mark Wade

The Osa concept was for a completely self-contained anti-aircraft missile system, which contained the search radar, missile guidance, and missile launchers all on one vehicle. Development was difficult, and it was over ten years from the beginning of work before the missile entered service.

Antey developed the Osa, Osa-M, and export Osa-AKM surface-to-air missile systems. These were deployed within Soviet tank divisions to provide close-in air defence. Development was begun in October 1960, with the decree designating M M Kosichkin at NII-20 GKRE as the prime contractor for the overall system and the semi-active radar; A V Potopalov at KB-82 Tushkin Machine Works GKAT for the surface-to-air missile; VNII Signal GKOT for the stabiliser for the radar antenna and the electronics for the launcher; and State KB Compressor Machine Works GKAT for the launcher. The Osa and Osa-M were developed simultaneously, the Osa-M being the naval version for the VMF, designed for last-ditch defence of ships against incoming attackers.

Problems occurred early when KB-82 proved unable to develop a surface-to-air missile with the necessary mass and dimensions. State trials were to have begun in the fourth quarter 1963, but instead a new decree was issued in September 1964 assigning development of the surface-to-air missile to Grushin at MKB Fakel GKAT, while at the same time setting more realistic specifications for the rocket. A dual-thrust solid propellant motor provided reduced thrust for the cruise phase, allowing range objectives to finally be met. This engine was developed by OKB-81 GKAT using a telescoping nozzle.

The Osa version for the surface forces began trials in the second half of 1967 under the auspices of the PVO. These were unsuccessful, and in July 1968 further tests were cancelled, and a new schedule was set for tests of a redesigned 9M33 missile to begin in the second quarter of 1970. Meanwhile NII-20 GKAT had been reorganised as NIEMI Minadrioprom, with V P Efremov as the new chief designer, and I M Drize as his deputy. A complete reevaluation of Osa led to development of a new design 9K33 transporter-launcher by Bryansk Auto Works. The redesigned system successfully completed factory trials in March-June 1970, and state trails in July 1970 - February 1971. The missile was finally accepted by the surface forces for production, over ten years after development had begun. Various versions of this missile saw service in the Persian Gulf War in 1991.

Maximum target speed 2160 kph.

Radars: P-40 Long Track early warning radar, E band, range 175 km. P-15/1RL13 Flat Face target acquisition radar, C band, range 250 km. Land Roll target acquisition radar, H band, range 30 km. Land Roll target tracking radar, J band, range 20 km. Thin Skin B height finding radar.

Manufacturer: Efremov/Grushin. Location: Moscow, Russian Federation. Total Mass: 126 kg (277 lb). Core Diameter: 0.21 m (0.68 ft). Total Length: 3.14 m (10.30 ft). Span: 0.64 m (2.09 ft). Standard warhead mass: 19 kg (41 lb). Maximum range: 10 km (6 mi). Boost Propulsion: Solid rocket, dual thrust. Guidance: Radio Command Link. Maximum speed: 2,450 kph (1,520 mph). Minimum range: 1.60 km (0.90 mi). Ceiling: 10,000 m (32,000 ft). Floor: 20 m (65 ft). Surveillance Radar: G/H. Tracking Radar: I.

In 1971-1974 a modernised version of Osa was developed with improved reliability.

The starting points were designated Osa-A and Osa-K. The basic Osa-A system had 6 surface-to-air missiles on the launcher, compared to four for he basic Osa system. The Osa-K housed the missiles as 'sealed units' in a transport-launch container that would not be opened between the factory and the moment of launch one tank-transporter complex. The final solution was a combined OSA-AK system, with a new 9A33BM vehicle, which would use the new 9K33M2 launch system and could hold six 9M33M2 Osa-A missiles. Parallel trials of the two missiles were completed in June 1974. State trials of the combined Osa-AK system were conducted from September 1974 to February 1975. The system was accepted for production by the PVO and surface forces by the end of 1975.

Standard warhead mass: 15 kg (33 lb). Maximum range: 10 km (6 mi). Guidance: Command. Minimum range: 1.50 km (0.90 mi). Ceiling: 5,000 m (16,400 ft). Floor: 25 m (82 ft).

Version of Osa with improved anti-helicopter capability.

In the mid-1970's a need was identified for a new version of Osa capable of shooting down the NATO helicopters that threatened Warsaw Pact tank formations. For this role a 9A33BM3 vehicle was developed that could fire a mixture of 9M33M3 radio-guided and wire-guided missiles from a single vehicle. In 1980, the modernised Osa-AKM 9K33M3 was accepted by the PVO and surface forces and began serial production at the Izhevsk Electromechanical Works Minradioprom (9A33BM3 missile) and at the Kirov Machinery Works named for the 20th Party Conference Minaviaprom (9M33M3 missile), where all Osa vehicles and their missiles were built.

Maximum target speed 2160 kph.

Total Mass: 170 kg (370 lb). Core Diameter: 0.21 m (0.68 ft). Total Length: 3.10 m (10.10 ft). Standard warhead mass: 40 kg (88 lb). Maximum range: 10 km (6 mi). Guidance: Radio command link. Maximum speed: 2,450 kph (1,520 mph). Minimum range: 1.50 km (0.90 mi). Ceiling: 13,000 m (42,000 ft). Floor: 10 m (32 ft).

Version of Osa used as a target drone.

The Izhevsk Works, with the assistance of Antey and MKB Fakel, developed the Saman and Saman-M target systems based on the Osa and Osa-M (9M33 and 9M33M). These simulated aircraft targets for surface-to-air missile and AA testing and training.

• Parsch, Andreas, DesignationSystems.Net, . Outstanding, unique reference for aircraft, missiles, propulsion, and avionics systems. Accessed at: http://www.designation-systems.net/.

• Yeftifyev, M D, Iz istorii sozdaniya zenito-raketnovo shchita rossii, Vuzovskaya kniga, Moscow, 2000. Comprehensive history of development of the development of surface-to-air and anti-ballistic missiles in the Soviet Union, with summaries of work in other countries as well. Accessed at: http://www.eastview.com/xq/ASP/sku=A2010232/f_locale=/Evtif'ev/MD/Moskva/Russia/Russian/qx/russian/books/product.asp.