Heinlein was a graduate of the Naval Academy, where he knew the family of Ernest J. King, later to be Chief of Naval Operations during World War II, and had dated one of his daughters and been the usher at the wedding of another. King, who was known throughout his life for his irascibility, took command of the aircraft carrier Lexington in 1930. Ensign Heinlein was assigned to the ship and served under King for the next year and a half and interacted with him frequently.[2] In Methuselah's Children, after the Families have taken over the starship, they appoint a Family member, Rufus ("Ruthless") King, to be its commander.