Navigation vents
Ascent Routine Mode
Provides the computations required for back-up ascent guidance. After the computer has been placed in the ascent mode, special data is transferred to the computer via the Digital Command System. This data is then continually updated and used to keep track of the orbit plane and the platform attitude with respect to Earth. Thirty seconds after the special data is first transferred to the computer, the Inertial Guidance System is placed in the inertial mode. The computer continually monitors and stores the platform gimbal angle values during this time. After lift-off, the computer performs a back-up guidance function. If necessary, however, the computer can he used to perform prlmary guidance during ascent.