David Altwegg, the U.S. Missile Defense Agency (MDA)’s top civilian official, ended his 64-year career in the federal government in February, the agency announced Feb. 23.

Altwegg was a U.S. Navy officer for 38 years, retiring from the service as a rear admiral in 1985. He came to the MDA in 2002 and six years later was appointed executive director, responsible for providing oversight and leadership of MDA personnel and interfacing with the military services, Office of the Secretary of Defense and Congress.

Altwegg’s successor at the MDA has not yet been chosen, agency spokesman Rick Lehner said March 1.