Flight Sequence Program

The flight sequence program is a series of scheduled commands that is being sent from the LVDC to the stages of the Saturn vehicle (S-IB/C, S-II, S-IVB and IU) during a mission. They are scheduled in various time bases. In NASSP the LVDC loads a flight sequence program file that is valid for a given mission. The file can be found under Config/Project Apollo.

TBD:

-Explain time bases

-Explain stage code

-List of all available Saturn IB and V commands

Sequences

Initiate LOX Dump (Saturn IB)

Prerequisites: Passivation Enable, Stage 3 (S-IVB), Channel 85

Event	Time from Event	Stage	Channel	Remarks
Aux Hydraulic Pump Flight Mode On	-22.0	3 (S-IVB)	28	The auxiliary hydraulic pump is turned on to center the J-2 engine for damping
Engine Mainstage Control Valve Open On	-0.2	3 (S-IVB)	30	Commands open main LOX valve
Engine He Control Valve Open	0.0	3 (S-IVB)	109	Provides pneumatics to open main LOX valve
LOX Tank NPV Valve Open On	10.0	3 (S-IVB)	42	The LOX NPV valve is latched open, if it is desired to do so
LOX Tank NPV Valve Open Off	12.0	3 (S-IVB)	37	Only if opened in the previous step

Terminate LOX Dump (Saturn IB)

Prerequisites: -

Event	Time from Event	Stage	Channel	Remarks
Engine Mainstage Control Valve Open Off	-1.0	3 (S-IVB)	65
Engine He Control Valve Open Off	0.0	3 (S-IVB)	110
Aux Hydraulic Pump Flight Mode Off	2.0	3 (S-IVB)	29

Initiate LH2 Tank Blowdown Vent (Saturn IB)

Prerequisites: -

Event	Time from Event	Stage	Channel	Remarks
LH2 Tank Vent Valve Open	0.0	3 (S-IVB)	38

Terminate LH2 Tank Blowdown Vent (Saturn IB)

Prerequisites: -

Event	Time from Event	Stage	Channel	Remarks
LH2 Tank Vent Valve Close	-3.0	3 (S-IVB)	76
LH2 Tank Ven Valve Boost Close On	0.0	3 (S-IVB)	77
LH2 Tank Vent Valve Boost Close Off	2.0	3 (S-IVB)	78