Most sailors are familiar with the names of Weems and Plath, a company which produces navigation equipment. But half of that duo, Captain Philip Van Horn Weems, also had a great impact on aviation and space exploration. Have any of the Mercury astronauts written about being trained by Capt. Weems? I knew him well in the 1960s as he worked with my father on Timation, a precursor system to GPS, and my family frequently went to Annapolis for Sunday brunch with him.
Both seafaring folks and pilots have grown used to depending upon computer-aided navigation, but it's easy to take for granted. Those who have heard of Weems tend to connect him to Charles Lindbergh, who had a great deal to learn from the Navy man about steering by the stars. He pioneered the Weems System of Navigation, which revolutionized the field.
By the time the space age dawned, Weems was in his seventies. But he had yet another patent in him: The "Method for Space Navigation." Weems taught the original Mercury Seven astronauts how to navigate celestially with his system.
Although guidance systems would do most of the work on the way to the Moon, it was important to have a human backup. The system was also later taught to a new recruit named Jim Lovell. Lovell applied his knowlegde on Apollo 8, and most likely the ill-fated 13 as well.