In May 1942, a lone Spitfire on a routine reconnaissance mission over northern Germany changed this. Flight Lieutenant D. W. Steventon brought back photographs of the Peenemunde airfield along the Baltic coast that revealed evidence of construction activity with circular emplacements on the ground. Photographic interpreters, however, were unable to locate anything out of the ordinary from the photographs. Intelligence reports months later disclosed that rockets at Peenemunde had been test-fired.
The first test flight of a V-2 rocket was made in October 1942.