 degree in Applied Physics and Electronics Engineering in 1964, and was a member of Phi Beta Kappa.McMullen served in the United States Navy from 1964 to 1969.Assigned to the staff of Admiral Hyman G. Rickover, the head of the Navy's nuclear submarine program, McMullen attained the rank of lieutenant as manager of a program that upgraded the service's nuclear-powered submarines with modernized reactors.