U.S. officials said the jetliner might have been mistakenly identified as a threat, and Ukrainian security officials said evidence pointed to a possible strike from a Russian Tor system. WHAT IS TOR The Tor short-range air defense system, code-named the SA-15 by NATO, was designed during Soviet times to shoot down aircraft and precision guided weapons.
It is mounted on a tracked vehicle and carries a radar and a pack of eight missiles. Each vehicle can operate independently. Tor has a range of up to 12 kilometers (7.5 miles) and can hit aerial targets at altitudes of up to 6 kilometers (about 19,700 feet).
Since Tor’s initial version in 1986, the system has been updated and improved regularly to enhance its capability. In 2017, Iran took the delivery of 29 Tor M1 units from Russia under a contract worth an estimated $700 million.
HOW IT WORKS It takes the system just a few seconds to detect a target and engage it. The missile explodes near the target, taking it down with shrapnel that devastates engines, fuel tanks and other vital components.
The Tor system is highly efficient, reportedly scoring up to 100 percent of hits during tests.