Conversation so far:
When did Robert A. Heinlein go to the Navy?
Shortly after graduating from the naval Academy in 1929, Robert A. Heinlein was commissioned as an ensign by the U. S. Navy.
Are there any other interesting aspects about the Robert A. Heinlein article?
Robert A Heinlein advanced to lieutenant, junior grade while serving aboard the new aircraft carrier USS Lexington in 1931, where he worked in radio communications with the carrier's aircraft.
What else was Robert A. Heinlein known for besides Starship Troopers?
Robert A. Heinlein was frequently interviewed by military historians about Captain Ernest J. King and his service as the commander of the U.S. Navy's first modern aircraft carrier.

Question: What did he do in the Navy?
Self-contained rewrite: What did Robert A. Heinlein do in Navy?