Free-return trajectories were studied by Arthur Schwaniger of NASA in 1963 with reference to the Earth–Moon system. Those trajectories were used for the first Apollo missions.
Mr. Schwaniger, who was referred to by friends and family as “A.J.” or “Art”, was born in Louisville, KY and attended Ahrens Trade School. He later attained a physics degree from the University of Louisville in the 1950s and was later drafted into the U.S. Army.
Mr. Schwaniger’s superiors quickly noticed his training and skills in the fields of mathematics and physics. A.J. began work with the ballistic missile program at the Redstone Arsenal in Huntsville, Alabama. His agency later became known as the Marshall Space Flight center under direction of NASA. A.J.’s career spanned the multiple missions to the moon and several shuttle launches. Mr. Schwaniger wrote several technical reports during his career that help immortalize him.
In these technical notes D-1833 and MTP-AERO-62-19, he only used metric units and nautical miles but no feet and other non metric units.
He used meter and km for distances, even Mm for 1000 km. Speeds in m/sec and km/sec.
His papers were distributed also to a few NASA scientists born in Germany, see the distribution list on page 47.