Dr La writes "Two metal objects, one cylindrical and a smaller round one, crashed near Buren Soum in the Tuv province of Mongolia, in an empty field, on 19 February. They are parts of an American Delta II rocket stage (nr. 35939, 2009-052C) that launched the military STSS Demo 1 & 2 satellites in September 2009. Both articles linked above say that the larger of the two objects is 7.5 meters in diameter, but in this photo it looks more like 7.5 feet. It is marked with the serial number '02728.' (The military STSS program is intended for space-based detection and tracking of missiles.) In the months leading up to the February 19 orbital decay over Mongolia, the fall of the rocket stage was followed by amateur satellite trackers. Based on their final orbit determinations just hours before the decay, the decay must have occurred near 3:32 UTC on February 19."