This was a British programme, at Altenwalde in occupied Germany and using the technical expertise of captured German personnel, to launch four captured V-2 ballistic missiles for research and experimental purposes (2/17 October 1945).
The US forces had already seized and moved most of the V-2 technology from the Mittelwerk underground facility at the Mittelbau-Dora concentration camp near Nordhausen and, before the Soviets arrived to take up their prearranged occupation of the area, the British had the opportunity to gather material.
The British assembled sufficient components to start the assembly of eight V-2 rockets. Some parts were still missing, however, and there followed a major search throughout Germany. Some 400 railway cars and 70 Avro Lancaster flights were used to bring the 250,000 parts and 60 specialised vehicles to Cuxhaven: the most elusive parts were the batteries required to run the gyroscopes of the guidance package.
The US supplied some tail assemblies from the larger number of missiles that they had taken. Many of the rockets and the hydrogen peroxide fuel used in the operation was provided by 'T' Force, a secret British army unit that had, in spring and summer 1945, searched for German military technology and scientists. The British had no information about handling and launch procedures, so these were undertaken by German personnel.