The Massachusetts Institute of Technology Instrumentation Laboratory, charged with the development of the Apollo guidance and navigation system, was in the process of studying the earth's sunset limb to determine if it could be used as a reference for making observations during the mid-course phase of the mission.

To obtain data for this study, the laboratory requested that photographic observations be made during the Mercury-Atlas 9 (MA-9) 1-day orbital mission. Photographic material from the Mercury-Atlas 7 (MA-7 - Carpenter flight) had been used in this study.