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For other uses, see A-104 (SA-8).
The 9K33 OSA (Russian: Оса; English: wasp) is a highly mobile, low-altitude, short-range tactical surface-to-air missile system. "9K33" is its GRAU designation. Its NATO reporting name is SA-8 Gecko.
[edit] DescriptionThe SA-8 was the first mobile air defence missile system incorporating its own engagement radars on a single vehicle. All versions of the 9K33 feature all-in-one 9A33 TELAR vehicles which can detect, track and engage aircraft independently or with the aid of regimental surveillance radars. The 6-wheeled transport vehicles are fully amphibious and air transportable. The road range is about 500 km. The radar system on the SA-8 TELAR received the NATO codename Land Roll, it was derived from the naval `Pop Group' radar system but is smaller since it does not require the elaborate stabilisation system. An improved system designated the SA-8B `Gecko' Mod 1, was first seen in Germany in 1980. It had improvements added to the launcher configuration, carrying six missiles in ribbed containers. The system is reported to be of the frequency-agile monopulse type. It 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. This twin antenna system permits the 'Land Roll' radar to control up to two missiles simultaneously against a single target. Furthermore the two missiles can be guided on different frequencies to further complicate ECM. There is also a tubular device fitted to and above the tracking radar, this is thought to be an EO/LLLTV optical tracker. This would be used to track the target when the main tracking radar is jammed by ECM. An 9K33 battery comprises four 9A33B TELAR vehicles and two 9T217 transloader vehicles with reload missiles. A reload time of five minutes has been reported per TELAR. In addition to the TELARs, each regiment is also assigned a single radar collimation vehicle on the same chassis as the TELAR (BAZ-5937). This vehicle assists in the alignment of the TELAR's radar systems, ensuring accurate target tracking and engagement. [edit] Variants
The 9K33M3 is also able[citation needed] to utilize the 9A33BM3 missiles which are wire-guided, presumably for use in an ECM-heavy environment where the radio command guidance may not operate properly. [edit] Missiles
Engagement range for the early versions is approximately 2-9 km (1.3-5.6 miles) and engagement altitudes of between 50-5000 m (164-16,400 ft). The 9M33M2 "OSA-A" missile extends the ranges out to 1500-10000m (1-6.2 miles) and engagement altitudes to 25-5000 m (82-16,400 ft). The 9M33M3 missile greatly enhances the altitude engagement envelope to 10-12000 m (33-42,500 ft), and as such are also able to fly further (about 15 km/9 miles) but the system is not able to engage targets at longer ranges, due to other factors such as the radar tracking of the missiles. The system is designed for use primarily against jet aircraft and helicopters in any kind of weather. The 9K33 missiles are 3.158 m (10.3 ft) long, weigh 126 kg (278 lb) and use command guidance. There is also a backup low-light optical tracking system for heavy ECM environments. The latest 9K33M3 missiles have the increased total weight of 170 kg (375 lb) in order to provide the extended range coverage and larger warhead. Propulsion is provided by a dual-thrust solid fuel rocket motor. Both versions feature a missile speed of around Mach 2.4 (peaking at around Mach 3) for a maximum target engagement speed of around Mach 1.4 for the original missile and Mach 1.6 for the M2\M3 missiles. The warhead for the initial and M2 versions weighs 19 kg (42 pounds), increased to 40 kg (88 lb) in the M3 version to improve performance against helicopters. All versions have impact and proximity fuzes. There have been unconfirmed reports of other possible versions of the missile with both infra-red and semi-active radar terminal homing seekers. Each TELAR is able to launch and guide two missiles against one target simultaneously. Kill probability is quoted as being 0.35-0.85 for the OSA and 0.55-0.85 for the OSA-AK and OSA-AKM (presumably depending upon target aspect, speed, maneuverability and radar cross section). Reaction time (from target detection to launch) is around 26 seconds. Time to prepare for engagements from being in transit is around 4 minutes and missile reloading takes around 5 minutes. Each battery of four TELARs is usually accompanied by two reload vehicles carrying 18 missiles in sets of three, with a crane mounted on the reload vehicles to assist in moving the missiles. When launched the booster motor burns for two seconds, this permits the radar to gather and control it at very short ranges (about 1.6 km). The sustainer motor has a 15 second burn, bringing the missile to a top speed of about Mach 2. Once launched the missile is command-guided for the whole flight, and the warhead is detonated by its proximity fuze or possible command. The warhead is said to have a lethal radius of 5 m at low altitude against a F-4 Phantom size target.[citation needed] [edit] Radars
"Land Roll" is mounted on the TELAR, "Long Track" on a tracked vehicle (a modified AT-T), "Flat Face" on a van and "Thin Skin" is mounted on a truck. "Land Roll" has a 360 degree sweep for target acquisition but a more limited cone in which it can track and engage targets. [edit] Deployment and HistoryAs well as the USSR/Russia, there are many export customers for this system, including Greece (from the former East Germany), Poland, Syria, Ecuador and Iraq, who used Osa systems during the 1991 Gulf War. The system was also seen used in the 2008 South Ossetia War by both Georgians and Russians[citation needed]. [edit] Operators
[edit] Former Operators
[edit] References
[edit] External links[edit] Notes
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