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Ralph D. Semmel, director of the Johns Hopkins Applied Physics Laboratory (APL), announced Wednesday that he will step down in July 2025, ending 15 years at the nation’s largest university research center.
A national search for Semmel’s successor has begun, led by a search committee comprised of JHU leaders and members of the APL board of directors. The committee is co-chaired by retired Navy Rear Admiral Gary Roughead, former chief of naval operations, JHU trustee and APL board member; and Edward Schlesinger, Benjamin T. Rome dean of the JHU GWC Whiting School of Engineering. The firm Odgers Berndtson will also assist with the committee’s search.
Ralph D. Semmel, director of the Johns Hopkins Applied Physics Laboratory. (Photo: Johns Hopkins APL)
During Semmel’s tenure as director, which began in 2010, the lab sharpened its strategic focus and created new initiatives to foster greater innovation, accelerating APL’s contributions to the Department of Defense, NASA, the intelligence community, and other federal agencies. Semmel led APL as it developed groundbreaking breakthroughs in areas such as air and missile defense, cyber, artificial intelligence and autonomy, hypersonics, space science and engineering, biomechanical engineering, undersea systems, special operations, strategic multi-service systems, biothreat defense, and materials science.
During his nearly 40 years at APL, Semmel has also contributed to the national security strategy and R&D communities as a member of the Defense Science Board, the U.S. Strategic Command Strategic Advisory Group, and various panels of the National Security Agency (NSA) Advisory Board; he currently serves on the Council on Foreign Relations. Semmel has served as chair, co-chair, or editor for numerous academic graduate programs, journals, conferences, and committees. He is a graduate of West Point with master’s degrees in computer science and systems administration and a doctorate in computer science.
Since its founding in 1942 to aid a nation at war, APL has had eight directors. Semmel is the lab’s second-longest-serving head, after its third director, Ralph Gibson, who held the position for 21 years, from 1948 to 1969.
