The SA-8 Gecko NATO code name (Russian name 9K33 OSA) is a russian made highly mobile, low-altitude, short-range tactical surface-to-air missile system. "9K33" is its GRAU designation. The development programme was protracted with major redesigns of both the missile and launch platform required. Extensive range testing of the Osa for the Land Forces was conducted at a test range in Kazakhstan in 1965 where many of the faults of the original system were discovered. The modified system was named Osa-M with most of the individual systems having to be redesigned and also many of the developing agencies changed. The Russian Army accepted the OSA-M for service in 1972. Series production of the system began in 1971. The SA-8 Gecko is intended for defence on troops on the march and in mobile combat, as well as of strategic ground facilities against air strikes delivered by manned or unmanned air vehicles flying at low and medium altitudes. All versions of the SA-8 Gecko feature all-in-one 9A33 transporter erector launcher and radar(TELAR) vehicles which can detect, track and engage aircraft independently or with the aid of regimental surveillance radars.
SA-8 Gecko: 9K33 "OSA" began development in 1960 and was introduced in 1971-1972 with four exposed 9M33 missiles per TELAR and a maximum range of 12 km. SA-N-4 Gecko: 9K33M "OSA-M" was introduced in 1972 and is the naval version of the system with two 9M33M missiles on a Zif-122 retractable rotating launcher and improved performance. It has been installed on Kara class guided missile cruisers, Kiev class VTOL cruisers and also the Kirov, Slava and Krivak classes. SA-8B Gecko Mod-0: 9K33M2 "OSA-AK" was introduced in 1975 with the new six-missile box launcher, each missile being a sealed round. SA-8B Gecko Mod-1: 9K33M3 "OSA-AKM" was introduced in 1980 with the maximum range extended to 15 km and maximum altitude to 12 km as explained above. Most OSA-AKM systems also feature an IFF antenna. Osa-AKM: upgraded version of the SA-8B Gecko Mod-1 Poland and Czech Republic made local modification of SA-8 Gecko.
SA-8 Gecko is armed with 6 missiles ready to fire, mounted on the roff of the vehicle. Missile is tracked by radio-command guiding system. Loading platform can carry from 2 to 6 guided missiles. The main fire-control radar consists of an elliptical rotating surveillance antenna mounted on top of the array, operates in H band (6 to 8 GHz) and has a 30 km acquisition range against most targets. The large pulsed J band (14.5 GHz) engagement antenna is mounted below it in the centre of the array and has a maximum tracking range of about 20 km. Mounted on either side of the tracking radar antenna is a small J band parabolic dish antenna to track the missile. Below this is a small circular antenna which emits an I band uplink capture beam to gather the missile shortly after launch. The final antennas in the array are two small white rectangular ones, one on either side of the array mounted alongside the I band. These are used for command uplink to the missile.
The driver's compartment at the front of the vehicle has accommodation for two, the driver and commander, with access to it via a hatch in the roof. There are no other entrance/exit hatches apparent on the vehicle.
The SA-8 Gecko is a six-wheeled design designated BAZ-5937. It is based on a number of earlier six-wheeled all-terrain vehicles developed by V A Grachev's design team at the Likhachev Automobile Plant in Moscow. The SA-8 Gecko is motorized with an 5D20 B-300 diesel engine developing 300 hp at 2,000 rpm and one gas turbine which is used as an auxiliary power unit. The road range is about 500 km.
The SA-8 Gecko vehicle is fully amphibious, being propelled in the water by two water-jets at the rear of the hull. Before entering the water, a trim vane, which is folded back onto the glacis plate when not in use, is erected at the front of the hull. The vehicle is fitted with an air filtration and overpressure NBC system together with IR systems for the commander and driver. SA-8 Gecko is air-portable in the Il-76 transport aircraft.
Each battery has four SA-8 SPU launcher vehicles and two 9T217BM2 TZM reload vehicles each with 12 reload rounds. The TZMs are supported by 24 ZIL-131 (6 × 6) cargo trucks used as missile transporter by the regimental Transport Company. The maintenance and repair unit uses the 9V242-1 automated mobile test station, the 9V914-adjustment tower, the 9V210M3-maintenance vehicle, the 9F372M3 SPTA-2 vehicle and the 9F632M electronic simulator for crew training.