By February 1946, over 100 Operation Paperclip German scientists had arrived to develop rockets and were attached to the Office of the Chief of Ordnance Corps, Research and Development Service, Suboffice (Rocket), headed by Major James P. Hamill. Although the scientists were initially "pretty much kept " (resulting in the nickname "Operation Icebox"), they were subsequently divided into a research group and a group who assisted with V-2 test launches at White Sands Proving Grounds. German families began arriving in December 1946, and by the spring of 1948, the number of German rocket specialists (nicknamed "Prisoners of Peace") in the US was 127. Fort Bliss rocket launches included firings of the Private missile at the Hueco Range in April 1945. In 1953, funding cuts caused the cancellation of work on the Hermes B2 ramjet work that had begun at Fort Bliss.