V-2 rocket offensive began on 8 September 1944, when "Lehr- und Versuchsbatterie No. 444" () launched a single rocket guided by a radio beam directed at Paris. Wreckage of combat V-2s occasionally contained the transponder for velocity and fuel cutoff. The painting of the operational V-2s was mostly a ragged-edged pattern with several variations, but at the end of the war a plain olive green rocket also appeared. During tests, the rocket was painted in a characteristic black-and-white chessboard pattern, which aided in determining if the rocket was spinning around its longitudinal axis. The original German designation of the rocket was "V2",
Order of 9 September 1944 Todor Petrov: Bulgarian Orders and Medals 1878–2005. Military Publishing House Ltd., Sofia 2005, , S. 208–212. Paul Ohm Hieronymussen: Handbuch Europäischer Orden in Farbe. Universitas Verlag, Berlin 1966, S. 158. Order of 9 September 1944 The Order of 9 September 1944 was an Order of Merit of the Kingdom of Bulgaria from 1945 to 1946, and of the People's Republic of Bulgaria from 1946 to 1990. It commemorated the Bulgarian coup d'état of 1944, it came in three classes, had both a civil and military division and was awarded for services connected with the Army revolt of 9 September 1944