EG/Chief, Guidance and Control DivisionDecember 6, 196868-PA-T-265APA/Chief, Apollo Data Priority CoordinationGDC required for TLI
In reference to your November 18 memo to me in which you state that the Gyro Display Coupler (GDC) is required to be operable for commit- ment to TLI, I would like to assure you that current C' mission rules reflect this requirement. It is agreed by everyone I have talked to that redundant attitude reference systems are required prior to leaving earth parking orbit and, of course, without the GDC there is no backup to the GNCS.
Please excuse this late reply. I took action on receipt of your memo and then failed to inform you of it until I recovered it yesterday from the bottom of my “Immediate Action” basket.