VEHICLE ASSEMBLY AT KENNEDY SPACE CENTERStages and modules that comprise the Saturn IB launch vehicle are brought together for the first time at Kennedy Space Center. There are over 90 operations performed for preflight testing and checkout. The S-IB stage, S-IVB stage, and Instrument Unit (IU) of the launch vehicle, as well as the major Apollo spacecraft modules, undergo numerous, complex testing operations to insure flight-ready space vehicles.
S-IB Stage Operations
The S-IB stage is transported by barge from Marshall Space Flight Center's Michoud plant to the Hangar AF-4 at Kennedy Space Center. After a receiving inspection and pre-erection preparation, the stage is transported to the launch complex and erected on the launch pedestal where the following operations are performed:
- Installation of Fins
- Power-on Checks
- Digital Data Acquisition Checks
- Radio Frequency and Telemetry Checks
- Electrical Networks Checks
- Mechanical Systems Checks
- RP-1 and Liquid Oxygen Loading Tests
S-IVB Stage Operations
The S-IVB stage is delivered from the Douglas Sacramento Test Center to Kennedy Space Center and transported to the low bay area of the Vehicle Assembly Building for receiving inspection and pre-erection preparation. The following operations are performed:
- Power-on Checks
- Digital Data Acquisition Checks
- Radio Frequency and Telemetry Checks
- Electrical Networks Checks
- Mechanical Systems Checks
The S-IVB stage is transported to the launch complex and erected and mated to the S-IB stage on the launch pedestal.
Instrument Unit Operations
The IU is delivered from Huntsville to Kennedy Space Center and transported to a hangar for receiving inspection and alignment of the inertial guidance platform. The IU is transported to the launch pad where it is mated to the S-IVB stage, and the following operations are performed:
- Cold Plate Checks
- Power-on Checks
- Digital Data Acquisition Checks
- Radio Frequency and Telemetry Checks
Integrated Launch Vehicle Operations
After the S-IB stage, S-IVB stage, and IU have been mated to form an integrated Saturn IB launch vehicle, the following operations are performed:
- Electrical Mating Checks
- Switch Selector Function Test
- Power Transfer Test
- Propellant Dispersion Functional Test
- Guidance and Control Tests
- Exploding Bridge Wire Functional Tests
- Sequence Malfunction Tests
- Emergency Detection Tests
Following these tests, the integrated Apollo spacecraft is mated to the Saturn IB Instrument Unit to form the Apollo/Saturn IB space vehicle. The following prelaunch operations are conducted:
- Integrated Test with Launch Vehicle Simulator
- Spacecraft/Launch Vehicle Electrical Mating and Interface Tests
- Spacecraft/Launch Vehicle Malfunction Detection Test
- Space Vehicle Integrated Test with Umbilicals Connected
- LES Mate and Thrust Vector Alignment Verification
- Space Vehicle Radio Frequency Compatibility and Swing Arm Test
- Space Vehicle Integrated Test with Umbilicals Disconnected
- Countdown Demonstration Test
a. Spacecraft Ordnance Installation and Removal
b. Spacecraft Water System and Oxygen System Servicing
- Space Vehicle Flight Readiness Test
- Launch Vehicle Umbilical Connection Verification
- First Stage (S-IB) RP-1 Loading
- Second Stage (S-IVB) APS Loading
- Spacecraft Hypergolic Fuel Loading
- Space Vehicle Launch Countdown
LAUNCH COUNTDOWN
Launch countdown commences many hours prior to the scheduled liftoff. Installation of pyrotechnics, final electro- mechanical checks, pressurization of pneumatic storage spheres, and loading of propellants are some of the terminal events that will be monitored from the blockhouse. The following chart identifies the countdown events and times from minus 300 minutes to liftoff. The times specified are subject to change and should not be considered final.
Launch Vehicle Flight Events
The following typical launch vehicle operations are listed for reference to post-liftoff events. The times specified are subject to change and should not be considered final.
Nominal Flight Time (Seconds) Flight Time Base (Seconds) Event 0.0 T1+0.0 Liftoff; range safety receivers on 10.0 T1+10.0 Change from S-IB stage single engine out to multiple engine out capability 39.0 T1+39.0 Command S-IB stage tape recorder RECORD 77.6 T1+77.6 Time of maximum Q 133.3 T1+ 133.3 Arm S-IB stage fuel and LOX engine cutoff sensors 138.3(approx) T1+ 138.3(T2+0.0) S-IB stage fuel or LOX cutoff sensors actuate140.3 T2+ 2.0 Command S-IB stage inboard engines shutdown 144.1 T2+ 3.8 Command recoverable cameras ON 146.6 T2+ 6.3 S-IVB stage ullage EBW system primed to fire ullage rockets 147.3 T2+ 7.0 Arm S-IB stage fuel depletion sensors; electrically interconnect outboard engines thrust OK switches 148.3 T2+ 8.0 S-IB stage fuel depletion actuates, or outboard engine thrust OK switches deactuate, and outboard engines shutdown 149.0 T2+ 8.7 Fire S-IVB stage ullage rockets to settle propellants in tanks 149.1 T2+ 8.8 (T3+ 0.0) Command S-IB/S-IVB stage separation; fire S-IB retrorocket to brake spent S-IB stage and S-IVB aft interstage start 150.7 T3+ 1.6 S-IB stage tape recorder playback and recoverable camera ejection delay timers 155.1 T3+ 6.0 Start S-IVB, J-2 engine after sufficient clearance between stages 161.4 T3+ 12.3 Activate S-IVB stage propellant utilization system 163.9 T3+ 14.8 S-IVB stage ullage rocket jettison EBW system primed to blow off ullage rockets Jettison spent ullage rockets to decrease S-IVB stage weight 171.8 T3+ 22.7 Launch escape tower jettison 630.0 T3+ 500.0 (T4+ 0.0) J-2 engine cutoff; propellant nearly depleted; engine is stopped on fuel depletion or IU command 630.5 to 632.1 T4+ 0.5 to 2.1 Auxiliary pump, range safety receiver, and PU system are turned off; all systems, having completed their functions, are turned off to conserve remaining battery power 660.0 T4+ 29.1 Telemetry turned off
Copyright 1997, 1998 by John
Duncan |