NASA asked Grumman to make a detailed study of LM-4 to determine any constraints that might prevent accomplishment of a lunar orbit mission.

All such constraints were to be defined in sufficient detail to facilitate a NASA review, and NASA expected Grumman-recommended action in each case. The information was requested before the LM-4 Customer Acceptance Readiness Review. Grumman was further asked to study LM-5 to determine constraints that might prevent accomplishment of the lunar landing mission. Again, all constraints were to include recommended action.