Operation Hydra was an attack by RAF Bomber Command on a German scientific research centre at Peenemünde on the night of 17/18 August 1943. Group Captain , CO of 83 Squadron, commanded the operation, the first time that Bomber Command used a master bomber to direct the attack of the main force. Hydra began Operation Crossbow, a campaign against the German V-weapon programme. The British lost 215 aircrew, 40 bombers and killed several hundred enslaved workers in the nearby Trassenheide labour camp. The Luftwaffe lost twelve night-fighters and about 170 German civilians were killed, including two V-2 rocket scientists. Prototype V-2 rocket launches were delayed for about two months, testing and production was dispersed and the morale of the German survivors was severely affected.