Recommendation for DAP mass properties initialization and update requirements

PA/Chief, Apollo Data Priority CoordinationJUN 17 1968EG23-125-68-678EG/Chief, Guidance and Control DivisionRecommendation for DAP mass properties initialization and update requirements

This memorandum is written to present recommendations for simple mission rules for updating the Apollo DAP data load mass properties and engine trims. Both the Flight Control Division and Flight Crew Support Division have recently requested information in this gen- eral area.

Enclosures 1 and 2 list DAP mass properties update and initialization requirements, and indicate operational procedures for implementation of these requirements. The DAP update requirements, recommended in enclosure 1, are divided into the two categories of “mandatory” and “desirable.” These requirements are applicable to the SUNDISK, COLOSSUS, and SUNDANCE/LUMINARY DAP's, and to all docked and undocked LM and CSM vehicle configurations. The DAP initialization require- ments, recommended in enclosure 2, are intended to be general enough to cover the main line Apollo missions, yet specific enough to have concrete value for any given mission.

Detailed rules for initializing and updating the DAP data loads will vary from mission to mission, and the enclosed data load requirements are written with that fact in mind. The enclosed requirements are recommended as “rules of thumb” to be updated as additional analysis and flight test data becomes available.