developed in the post-war period. Developed late in the war, X-4 does not appear to have been used in combat. Post-War Activities in the United States Kramer relocated to the United States after World War II as part of Operation Paperclip. From 1947 to 1952 he worked for the Pilotless Aircraft Laboratory at the Naval Air Development Station in Johnsville, Pennsylvania conducting research on autonomous air vehicles and missiles and building upon his research on the X-4. Kramer left government employment in 1952 to take a position as Technical Director with Coleman Engineering Company where his work focused on the highly efficient movement of structures through fluids via creation of laminar flows. He often reported that on crossing the Atlantic he noticed dolphins have a shape implying laminar flow and that this was the inspiration for his research. However, he had been researching laminar-flow issues long before he came to the U.S. After ten years of effort he discovered that a compliant coating, such as the skin of a dolphin would dampen any turbulent tendencies resulting from movement through water. He claimed that a 30% reduction in drag was possible, but subsequent researchers were unable to duplicate these results, leading to what has been called "The Kramer Controversy." Over time, as more research on the topic has been conducted, scientists have gradually confirmed Dr. Kramer's pioneering views. In 1956, in order to monetize Kramer's research on “Boundary Layer Stabilization by Distributed Damping,” Coleman Engineering and Kramer founded a jointly-owned company, Coleman-Kramer, Inc. The result of this combined effort was a new material designed to reduce drag in underwater vehicles emulating the compliant skin of porpoises. In 1957 the technology was licensed to US Rubber Co. for manufacturing, under the trademark Lamiflo. The Navy wasn't interested in this material, so Kramer patented it. Later the FBI claimed he sold it to the Russians. Kramer died in June 1986 in Pacific Palisades, California. References http://www.ausairpower.net/WW2-PGMs.html http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1158548 https://web.archive.org/web/20060821133954/http://www.spawar.navy.mil/sti/publications/pubs/tr/1801/tr1801.pdf Article title 1903 births 1986 deaths German rocket scientists Technical University of Munich alumni German emigrants to the United States