The words, ex luna scientia were inscribed on the mission patch worn on the uniforms of the crew of Apollo 13.

The phrase was the motto of the moon mission and was derived from ex scientia tridens, the motto of Jim Lovell's Alma Mater, the United States Naval Academy.

Jim Lovell was a former NASA astronaut and a retired captain in the United States Navy, who was most famous as the commander of the Apollo 13 mission, which suffered a critical failure on the way to the moon, but it was brought back safely to earth with the skills of the crew and the mission control staff.