John F. Plumb served as the first Assistant Secretary of Defense for Space Policy from April 2022 to May 2024, overseeing space warfighting policy for the U.S. Department of Defense. His portfolio included strategic deterrence capabilities spanning space, nuclear weapons, cyber, missile defense, electromagnetic warfare, and countering weapons of mass destruction.

Among his accomplishments were leading the classified Space Strategic Review; the unclassified Commercial Space Integration Strategy; the 2022 Missile Defense Review; the 2022 Nuclear Posture Review; and the unclassified Space Policy Review and Strategy on Protection of Satellites. He also led a complete rewrite of the Department’s space classification policy and spearheaded the expansion of the Combined Space Operations Initiative from seven to 10 allied nations.

Dr. Plumb has more than 30 years of experience in national security roles both in and out of uniform. He served as an active-duty U.S. Navy fast-attack submarine officer and later commanded multiple Navy Reserve units, retiring with the rank of Captain (O-6). His civilian career has included staff roles in the U.S. Senate, the Pentagon, and the White House National Security Council, as well as senior positions at RAND Corporation and The Aerospace Corporation.

He earned a bachelor’s degree in physics from University of Notre Dame and both a master’s degree in physics and a Ph.D. in aerospace engineering from University of Colorado Boulder.

Dr. Plumb currently serves as Head of Strategy for K2 Space, a startup based in Torrance developing large, powerful, radiation-tolerant satellites at low cost and at scale.