- Date: Jul 11 1966
- From: FM/Deputy Chief, Mission Planning and Analysis Division
- Subject: Capability to do orbit navigation in earth orbit will not be implemented for AS-207 or AS-504.
MIT currently has plans for supplying a number of different modes for using their basic orbit determination program. (MIT calls this process “navigation,” so I will, too.) These modes differ in that there is a variety of types of observational data used during different mission phases.
In our attempt to simplify the AS-504 spacecraft computer program, we are reviewing the overall situation to determine that no unnecessary modes are included. For example, there is no need to perform orbit navigation while in earth orbit for the lunar mission or any recognized contingency situation. This particular orbit navigation mode was to utilize star/landmark observations along with other earth orbital service routines and special initialization capabilities to determine the spacecraft state vector prior to the translunar injection maneuver. Since this program is not required for the lunar mission, MIT will be directed not to include it in the AS-504 program. Since we do not intend to implement any programs especially for AS-207, unless directed otherwise, it will be dropped from the AS-207 computer program as well, which means that the CSM will not have the capability of determining its own orbital elements during that mission.
Accordingly, it will not be possible to satisfy that mission objective as referenced in TRW document 2132-H008-R8-000, “Mission Requirements for Apollo Spacecraft Development Mission AS-207/208” dated March 7, 1966, classified Confidential.