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",
Rocket artillery effectiveness. The Japanese 20 cm rockets were launched from tubes or launching troughs, while the larger rockets were launched from steel ramps reinforced with wooden monopods. The Japanese also deployed a limited number of 447mm rocket launchers, termed 45 cm Rocket Mortars by United States personnel who test-fired them at the close of the war. Their projectiles consisted of a 1,500 lb cylinder filled with propellant and ballistite sticks detonated by black powder, which produced a blast crater approximately the size of an American 1,000 lb bomb. In effect, this made the 447mm projectile a type of surface-to-surface barrel bomb.