By that time, the British and Soviet intelligence agencies were aware of the rocket program and von Braun's team at Peenemünde, based on the intelligence provided by the Polish underground Home Army. Over the nights of 17-18 August 1943, RAF Bomber Command's Operation Hydra dispatched raids on the Peenemünde camp consisting of 596 aircraft, and dropped 1,800 tons of explosives. The facility was salvaged and most of the engineering team remained unharmed; however, the raids killed von Braun's engine designer Walter Thiel and Chief Engineer Walther, and the rocket program was delayed.