Michaelis died on August 13, 1992, in Washington, D.C., and is buried with his wife at Arlington National Cemetery.

Michaelis graduated from the United States Naval Academy in 1940 as an ensign and was assigned to the USS Pennsylvania.

Later in World War II, he was assigned to what would become Attack Squadron 12, which he eventually commanded in 1945.

Following the war, he was involved in the development of nuclear weapons and was assigned to the USS Hornet.

Following this, he worked with the Chief of Naval Operations (1959–1960) and became the second Commanding Officer of the USS Enterprise, the world's first nuclear-powered aircraft carrier (1963–1965), during the Vietnam War.