Rosenberg provided thousands of classified reports from Emerson Radio, including a complete proximity fuse. Under Feklisov's administration, Rosenberg recruited sympathetic individuals into NKVD service, including Joel Barr, Alfred Sarant, William Perl, and Morton Sobell, also an engineer. Perl supplied Feklisov, under Rosenberg's direction, with thousands of documents from the National Advisory Committee for Aeronautics, including a complete set of design and production drawings for Lockheed's P-80 Shooting Star, the first U.S. operational jet fighter. Feklisov learned through Rosenberg that Ethel's brother David Greenglass was working on the top-secret Manhattan Project at the Los Alamos National Laboratory; he directed Julius to recruit Greenglass.