Nordhausen and Bleicherode area in Thuringia to the Soviets, U.S. Army Major Robert B. Staver, Chief of the Jet Propulsion Section of the Research and Intelligence Branch of the U.S. Army Ordnance Corps in London, and Lieutenant Colonel R. L. Williams took von Braun and his department chiefs by Jeep from Garmisch to Munich, from where they were flown to Nordhausen. In the following days, a larger group of rocket engineers, among them Helmut Gröttrup, was evacuated from Bleicherode southwest to Witzenhausen, a small town in the American Zone. Von Braun was briefly detained at the "Dustbin" interrogation center at Kransberg Castle, where the elite of Nazi Germany's economic, scientific and technological sectors were debriefed by U.S. and British intelligence officials. Initially, he was recruited to the U.S. under a program called Operation Overcast, subsequently known as Operation Paperclip. There is evidence, however, that British intelligence and scientists were the first to interview him in depth, eager to gain information that they knew U.S. officials would deny them. The team included the young L.S. Snell, then the leading British rocket engineer, later chief designer of Rolls-Royce Limited and inventor of the Concorde's engines. The specific information the British gleaned remained top secret, both from the Americans and from the other allies. American career U.S. Army career On 20 June 1945, U.S. Secretary of State Edward Stettinius Jr. approved the transfer of von Braun and his specialists to the United States as one of his last acts in office; however, this was not announced to the public until 1 October 1945. The first seven technicians arrived in the United States at New Castle Army Air Field, just south of Wilmington, Delaware, on 20 September 1945. They were then flown to Boston, Massachusetts, and taken by boat to the Army Intelligence Service post at Fort Strong in Boston Harbor. Later, with the exception of von Braun, the men were transferred to Aberdeen Proving Ground in Maryland to sort out the Peenemünde documents, enabling the scientists to continue their rocketry experiments. Finally, von Braun and his remaining Peenemünde staff (see List of German rocket scientists in the United States) were transferred to their new home at Fort Bliss, a large Army installation just north of El Paso, Texas. Von Braun later wrote that he found it hard to develop a "genuine emotional attachment" to his new surroundings. His chief design engineer Walther Reidel