Burma has assigned some of its new Russian S-125 anti-aircraft missiles to shoot down a mysterious UAV that has been spotted several times in the last month near the Chinese border. Burma has been unable to identify the owner of the UAV, and anti-aircraft weapons in the area (small caliber autocannon and shoulder fired missiles) have not been able to hit the high flying UAV.
Burma is one of about ten export customers for Russia's 1970s era S-125 (SA-3 Goa) surface-to-air missile system. Known customers are Libya, Syria, Venezuela, Myanmar, Vietnam and Turkmenistan. Some of these countries are buying updated launchers and radars as well. While the basic design of the S-125 is old, it has been frequently updated.
The two stage S-125 missiles weigh nearly a ton, and carry a 59 kg (130 pound) warhead against targets 35 kilometers away (and altitudes as high as 18,000 meters). There is also a smaller missile, weighing closer to half a ton, with a range of 15 kilometers. Having two different size missiles for the same system is a common practice with the Russians (and some other nations as well, like the U.S. Patriot system).
Users have upgraded or modified their S-125 missiles and radars themselves over the years. The most notable example of this was in Serbia, in 1999, where a missile battery commander used S-125s to shoot down a U.S. F-117 stealth aircraft. He did this by using human observers a lot, and his radar rarely. Since the S-125 can be controlled (flown by) a ground operator, once the F-117 was located, an S-125 missile was launched and flown manually to the target. Simple and effective, and largely immune to countermeasures.
This feat gave S-125 sales a shot in the arm, and three years ago the Russians opened a new factory to meet the demand (worth over $250 million). But nations don't buy the inexpensive, and reliable, S-125 because one took down a stealth fighter. No, the missile provides basic air defense against neighbors who don't have high-end air forces. The S-125 provides basic air defense, and keeps aerial smugglers, and secretive users of UAVs, nervous.