When the Apollo astronauts land on the Moon, their precise location will not be known. The real-time geologic mapping planned for the first mission could best be done if the exact position of the landing site were determined. The astronauts may have to find their position, with or without assistance from the Earth-based scientific mission center, before leaving the Lunar Module (LM), and the less time this takes, the more time will be available for exploring the lunar surface.
These considerations suggested the following questions: Could astronauts accurately locate themselves and how much time would it take?
The U.S. Geological Survey began studying this problem in July 1967. A crater field replica of a portion of the lunar surface was constructed and an LM mockup placed on it. Test subjects were asked to locate their exact position on a Lunar Orbiter photograph by comparing the photograph with the crater patterns visible through the LM windows. This "curiosity" test was part of a general survey of the problem and was intended to generate ideas that would enable intelligent planning of detailed tests if such tests become necessary.
