As the world reacts to news of a Malaysian passenger jet shot down over the Ukraine, facts about what happened are few and far between. Media outlets such as The New York Times and Aviation Week report that the jetliner was flying at about 33,000 feet when it went down. Speculation immediately began swirling about the type of weapon used in the incident. The Times also reports that rebels there were in possession of Russian-made SA-11 surface-to-air missile systems which were capable of hitting the plane at that altitude. It is also reported that Russian troops stationed along the Ukrainian border have similar SAMs and other weapons known as SA-20s. 

Details about these systems come from the Defensetech.org site, which reports that four Soviet SAM systems would have been capable of reaching the Malaysian jet. Besides the SA-11, Defensetech names the SA-17, the S-400, the 2K12 Kub, and the S-75A Dvina.

The SA-11, also known as a Buk missle system, is a mobile device which Defensetech.org says includes a target acquisition radar vehicle, command vehicle, six transporter erector launcher and radar vehicles, and three transporter erector launcher vehicles.

Use of shoulder-fired surface-to-air devices in this case is ruled out by the altitude at which the plane flew. For example, the 9K32 Strela-2 Soviet system is a man-portable, shoulder-fired system with a high explosive warhead and passive infrared homing guidance.  But its maximum range is said to be a little less than 14,000 ft.