Gene Fastook, who helped make it possible for humans to walk on the moon and return to Earth to tell the tale, now begins most days in a McDonald’s on White Plains Road in the Bronx, gabbing with other military veterans.

In the afternoon, Mr. Fastook drives over to the 47th Precinct station house, where he serves as a captain in the police auxiliary, a volunteer uniformed reserve that he joined in 1981. At 92, he is the second-oldest person serving in the New York Police Department.

Hunched over a logbook at his desk in the 47th last week, Mr. Fastook followed his finger down the page to see who had been on duty and who would be reporting in. The same active, restless spirit drove him, at age 17, when he was a senior at Brooklyn Tech high school, to forge his mother’s signature and enlist in the Navy. He served in the Pacific aboard landing ship tanks, which get cargo and vehicles right to the shoreline. “They were called L.S.T.s, with a top speed of 10 knots,” Mr. Fastook said. “We said it stood for ‘Low slow target.’”

Prompted by his sons, Eddie and Gene Jr., Mr. Fastook recalled bits of his careers at sea and in the skies.