On October 22, 1946, the Operation Osoaviakhim forcibly removed more than 2,200 German specialists – a total of more than 6,000 people including family members – from the Soviet occupation zone of post-World War II Germany for employment in the Soviet Union. 160 specialists from Institut Nordhausen, headed by Helmut Gröttrup, were held on Gorodomlya Island until 1953. As the first task, they had to support the Soviets in building a replica of the V-2 which was called the R-1 and successfully launched in October 1948. The Soviets eventually requested concepts of more powerful boosters for higher payload and range, i. e. nuclear warheads and long-range distance. Therefore, from 1947 to 1950, the German collective proposed concepts for the G-1, G-2 and G-4 with numerous design improvements over the V-2 status: