Johns Hopkins University Applied Physics Laboratory

The Johns Hopkins University Applied Physics Laboratory, known as APL, is a not-for-profit, United States Navy-sponsored University-Affiliated Research Center in Howard County, Maryland. It is affiliated with Johns Hopkins University and employed more than 8,800 people as of 2025. APL was established in 1942 during World War II under the Office of Scientific Research and Development's Section T, with Merle Anthony Tuve as its founding director, and its first great success was the variable-time proximity fuze. It began in a used-car garage in Silver Spring, Maryland, and moved to Laurel from 1954. Expected to disband when the war ended, it instead became deeply engaged in guided missile technology for the Navy. Today it serves every branch of the Department of Defense, the Intelligence Community, NASA and other agencies, with work in air and missile defense, undersea warfare, computer security and the construction of spacecraft.