A combination of these techniques was first used on a large raid to great success on the night of 17/18 August 1943 in Operation Hydra against German rocket research at Peenemünde. 596 aircraft were led by a Master Bomber to a series of target indicators dropped at several different locations around the target area. By dropping different colours of indicators and calling aircraft to attack each one in turn, the entire area was heavily bombed. The aircraft from No.5 Group used their time-from-landmark technique again. The estimate has appeared in many sources that this raid set back the V-2 experimental programme by at least two months and reduced the scale of the eventual rocket attack. The V-2 team had to hastily move their testing facilities elsewhere. The Master Bomber became a common feature of large-scale raids from this time onwards.