Saturn 1B Launch Vehicle Flight Evaluation Report SA-208 Skylab-4

8/8/2019 Saturn 1B Launch Vehicle Flight Evaluation Report SA-208 Skylab-4

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SATURNMPR-SAT-FE-744 JANUARY 31, 1974

SATURNB LAUNCH EHICLEFLIGHT VALUATIONEPORT-SA-2Q

SKY AB-4 .9) SATURN 1U LAUNCHEVAL UATTON REPOtiT SA-208Sh) 250 p EC 57.50 N75-10140CSCL LZC Uncilasc3/15 52706

PREPARED YWORK116


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6EOR6EC. MARSHAll SPACE FLIGHTCENTERMPR-SAT-FE-74-1 JANUARY31, 1974

SATURNB LAUNCH EHICLEFLIGHTEVALUATIOI?REPORT-SA-208SKY AB-4

PREPARE0 YSATURMFLIGHTEVALUATIOWWORKlM6GROUP


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MPR-SAT-FE-74-1SATURN IB LAUNCH VEHICLE FLIGHT EVALUATION REPORT - SA-208

SKYLAB-4BY

Saturn I'light Evaluation Working GroupGeorge C. Marshall Space Flight Center

ABSTRACT

The Saturn IB, SA-208 Launch Vehicle was launched on November 16, 1973from Kennedy Space Center and placed the Command and Service Module con-taining three crew members into an 150.10 x 227,.08 km altitude earthorbit. No anomalies occurred that seriously affected the mission.Any questions or comments pertaining to the infonnation contained inthis report should be directed to:

Director, George C. Marshall Space Flight CenterHuntsville, Alabama 35812Attention: Chairman, Saturn Flight Evaluation WorkingGroup, SAT-E (Phone 205-453-1030)


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PRECEDINGPAGEBLANKN~ -TABLE OF CONTENTS

TABLE OF CONTENTSLIST ?: ILLUSTRATIONSLIS? CF TABLESACKNOYLEDGTMENTABBREVIATIONSMISSION PLANFL lGII1 SUFMARYMISSION OBJECTIVES ACCDMPLISHMENTFAILURES AND ANOMALIES

SECTION1.11.21.3SECTION2.12.2SECTIDN3.13.23.33.43.4.13.4.23.4.33.53.5.13.5.2

SECTiON4.14.24.2.14.2.2

1 - INTRODUCTIONPurposeScopePerformance PredictionsBaseline2- EVENT TIMESSumMry of EventsVariable Time and CommandedSwitch Selector Events3 - LAUNCH OPERATIONSC uma ryPrelaunch MilestonesTermlnal CountdownPropellant LoadingRP-1 LoadingLOX LoadingLH; LoadingGround Suppcrt Equipmen tGround/Vehicle InterfaceMSFC Furnished Ground SupportEquipment4 - TRAJECTORYSurmlaryTrajectory EvaluationAscent PhaseOrbital Phase

Page111VVii1IXXlxvXVIIXX Irxlil

1-ll-ll-li-l2-12-l2-13-l3-13-lj-13-l3-l3-33-3j-43-43-44-14-l4-14-l4-9

SLCTION 5 - S-IVL?/IU OEORBIT TR AJECTO RY 5-15.1 Sumnary 5-l5.2 Deorb jt Maneuvers 5-15.3 Deorbit Trajectory Eva!uation 5-2

5.4 ImpactSECTIDN 6 - S-IB PROPULSION6.16.26.36.46.5

:::.I6.6.26./6.8

SumryS-18 Ignitlon Transien tPerformanceS-IB Halnstage PerformanceS-IB Shutdown Transien tPerformanceS-18 Stage PropellantManagementS-IB Pressurlzatlon SystemFuel Pressurizatlon SystemLOX Pressurlratlon SystemS-IB Pneum atic ControlPressure SystemS-IB Hydraulic System

SECTION 7 - S-IVB PROPULSION7.17.27.37.4

7.5

7.67.6.17.6.2

7.7

7.07.97.107.10.17.10.27.10.37.10.4

SumnaryS-IV0 Chilldown and BulldupTransient PerformanceS-IV0 Malnstage PerformanceS-IVB Shutdown Transien tPerformanceS-IVB Stage PropellantManagementS-IV6 Pressurlzatlon SystemS-IVB Fuel Pressurlrationsys tenS-IVB LOX PressurlzatlonsystemS-IVE Pneum atic ControlPressure SystemS-IVB Auxiliary PropulsionSys ternS-IVWIU Stage DeorbitPropellant DumpS-IV6 Orbltal Coast and SaflngFuel Tank Orjital Coast andSafingLOX lank Orbltal Coast andSafinqCold Hellum DumpStaqe Pneum atic Control andEngine Control Sphere Safing

Page5-26-16-l6-l6-26-66-66-136-136-156-18

6-11:7-l7-l7-27-27-127-127-137-137-157-20

7-207-257-287-287-347-357-35


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TABLE OF CONTENTS (CONTINUED)

7.11SECTION8.18.28.2.18.2.28.2.38.2.48.38.3.18.3.2SECTION9.19.29.3

i99:33:*9.3.39.3.49.49.4.19.4.2SECTION10.110.2

10.310.3.110.3.210.3.310.410.510.5.110.5.2SECTION11.111.211.311.4

S-IVB Hydraulic System8- STRUCTURESSumnaryTotal Vehic le StructuresLongitudinal LoadsBending momentsCombined LoadsVehicle DynamicCharacteristicsStructural AssessmentFuel Tank Forward BulkheadDamageStress Corrosion Cracklng9 - GUIDANCE AND NAVIGATIONSumnaryGuidance ComparisonsGuidance and NavigatlonScheme EvaluationFirst Stage BoostSecond Stage BoostOrbital PhaseDeorbft PhaseGuidance and NavigatlanSystem ComponentsST-1249 Stabilized PlatformSystemGuidance Ccanputer10 - CONTROL AND SEPARATIONSunmaryS-IB Control SystemEvaluationS-IV8 Control SystemEvaluationS-IVB Control SystemEvaluation Durino BurnS-IVB Control SyitemEvaluation During OrbitS-IV8 Control SystemEvaluation During DeorbitInstrument Unit ControlComponents EvaluationSeparationS-16/S-IVB SeparationS-IYB/CSH Separationll- ELECTHICAL NETWORKS AR0

Page7-35

8-l8-l8-188::8-88-88-17B-l?8-l?9-l9-19-19-6

z-t-cj:g9-109-109-109-1210-l10-lID-110-210-810-810-1410-19lo-1910-1910-1911-IEMERGENCY DETECTION SVST EH

Sucsnary 11-lS-IB Stage Electrica l System 11-lS-IVB Electrica l System 11-4Instrument Unit Electrica l 11-9system

11.4.111.5SECTION12.1SECTION13.1SECTION14.114.214.314.3.114.3.214.3.3SECTION15.115.215.315.3.1

15.415.5is.615.7SECTION16.116.2SECTION

Prelaunch Power Transferlest AnomalyEmergency Detectlon System12 - VEHICLE PRESSUREENVIRONMENTS-IB Base Pressure13 - VEHICLE THERMAL ENVIRONR ENTS-IB Base Heating14 - ENVIRONMNTAL CONTROL SYSTEIISSunmryS-18 Environmental ControlIU EnvIronmental ControlThermal Conditionln System (TtS)Gas Bearing System 9 GBS)Component Temperatures15 - DATA SYSTEHSSumaryVehicle Measurement EvaluationAirborne Telemetry SystemEvaluationIU OF-1 Telem etry Link RFPower Output VariationsC-8and Radar System EvaluationSecure Range Safety CamiandSystems EvaluationDigltal Ccwmnand System EvaluationGround Engineering Cameras16 - NASS CHARACTERISTICSSunnaryHass Evaluation17 - SPACECR AFT SWMRY

Page11-1311-1412-112-l13-113-I14-114-l14-114-l14-114-214-215-115-l15-115-l15-2

15-715-915-915-916-l16-l16-l17-l

APPENDIX A - ATHDSPHERE A-lAPPENDIX 8 - SA-208 SIGNIFICANT B-lCONFIGURATION CHARGES

i . .


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LIST OF ILLUSTRATIONS

Figure2-l4-14-2

4-34-4

4-55-l5-26-l6-26-36-46-56-6G-76-8

6-96-106-11

G-126-136-146-15i-i7-2J-37-4

7-5

LVDC Cloc&/Ground lime DifferenceAscent Trajectory PosltibnComparisonAscent Trajectory Space-FixedVelocity and Flight Path AngleComparisonAscent Trajectory AccelerationComparisonAscent Trajectory DynamicPressure and Mach NumberComparisonLaunch Vehic le Ground TrackS-iVB/iU Stage Deorbit Alt!tudeHistory (No Breakup Assumed)S-iVS/!U Ground Track Dump toimpactS-19 Engine Thrust BuildupS-18 Stage Propulsion PerformanceS-IB LOX FlowrateS-16 Fuel FlowrateS-IB inboard Engines TotalThrust DecayS-IB Outboard Engine TotalThrust DecayS-IR LOX Mass Above Main LOXValveS-IB Fuel Mass Above MainFuel ValveS-IE Fuel Tank U!lage PressureS-10 rue1 Tank HeliumPressurization Sphere PressureS-IB Center LOX Tank UllagePressureS-IB Center LOX Tank UllagePressureS-IB GOX Flow Control ValvePositionS-Ii3 Pneum atic Control PressureS-IB Maximum Gimbal AngleS-IV0 Start Box and RunRequirementsS-IVB Steady-State PerfonsanceS-IV6 Engine Control BottlePressureS-IVB Gas Generator ChamberPressure (0010)S-IV!3 Gas Generator ValvePosition

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4-54-a

4-125-35-b6-36-46-56-56-86-96-126-12

6-146-166-176-196-206-216-237-37-57-67-07-9

Figure7-67-77-07-9?-!O7-11

7-127-137-147-157-167-177-187-197-207-21

7-228-l8-28-3

8-4B-5

8-6

0-7

B-8

V

S-IVB Engine Regulator OutletPressure (0018)S-IVE Engine Pneum atic SystemPm-Start of Cutoff ModeS-M LH2 Ullage Pressure -Preiiftoff. Boost and BurnS-IV6 Fuel Pump Inlet Conditions+IVB LOX lank Ullage Pressure -Boost PhaseS-IVB LOX Pump Inlet Condltlons -BurnS-IVB Cold Helium Supply HistoryS-IVB APS Module No. 1 PropellantUsageS-IVB APS Moduel No. 2 PropellantUsageS-IVB APS Chamber Pressure(Spacecraft Separation Disturbance)S-IVB APS Valve, injector, ThrustChamber AssemblyS-IVB Deorbit Propellant Dumpand Safing SequenceS-IVB LOX Dump Parameter HistorlesS-IV6 LH2 DumpS-IV0 LH2 Ullage Pressure -Orbital CoastS-IVE LH2 NPV Nozzle PressureOscillationsS-IV6 LOX Tank Ullage Pressure -Orbit, Dump, and SafingLongitudinal Acceleration DuringThrust Buildup and LaunchLongitudinal Load from StrainData at Station 942Longitudinal Load Distribution atTime of Maximum Bendlng Ptomentand IECOLongitudinal Acceleration DuringCutoffsPitch Bending Mrment Distributionsat Time of klarimwn ResultantMomentyaw Bending Mnent Distributionsat Tine of Maximum ResultantMoiwntResultant Bending Moment Dfstri-butlons at Tlme of MaximumResultant MomentCombined Loads Producing FiinimumSafety Margin During SA-POEI Flight

Page7-107-117-147-167-177-18

7-197-21

7-227-24

7-767-277-297-307-317-337-36 28-28-2

6-3

8-4

8-S

8-6

0-7

8-9 ;


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Figure8-98-108-118-128-13

8-14E-158-16El-178-169-l

9- 29-39-49-5

10-l10-Z10-3lo-410-510-610-710-813-Y:o-1010-11

LIST OF ILLU~TR~~N~ (CONTINUED)

Minimum Factor of SafetyDuring SA-208 S-16 flightVibration Measured DuringFirst Stage BurnVehicle Bending FrequenciesVehicle Bending AmplitudesLow Frequency Vibration andPressure Oscilla tions t&suredDuring S-IVB Stage BurnLow frequency Analysis ofVibration and Engine PressuresS-IV6 Engine Cutoff Transien tsS-IB Outrigger Assembly ChannelRepairS-I@ Fin Rel torclng BlockInstallationS-I@/S-IVB Interstage ReactlonBeamSA-208 Trajectory and ST-124MPlatform Velocity Comparisons(OMPT Minus LVDC)Roll Cozanand During QoostPitch Cowand Uur+ng BoostYaw Command During @oostSA-208 Inertlally-ReferencedVelocity Changes in Earth OrbitPitch Plane Dynamics DuringS-1B BurnYaw Plane Dynamics During S-IDBurnRoll Plane Dynamics DuringS-IQ EurnPitch and Yaw Plane Free StreamAngle of Attack During S-IB BurnPitch Plane Dynamics - S-IVD BurnYaw Plane Dynamics - S-IV6 BurnPitch Plan e Dynamics DuringOrbit [Sheet 1 of 2)SA-208 Vehicle Dynamics DuringLH2 NPV Relief VentingVehicle Dynamics During Deorbit(Sheet 1 of 2:S-III/S-IV6 LongitudinalAccelerationAngular Veioc itles DuringS-IQ/S-IVB Separation

Page Flgure8-10 11-l

a-11 11-Z

8-12P-138-14

11-511-411-5

8-15 li-68-168-188-198-209-2

l!-711-811-912-l12-z12-312-413-l9-7

9-8s-39-11

13-2

13-3

10-3 13-4

IO-4 13-s

10-S 13-6

10-7 13-7

10-910-1010-12

13-8

13-910-15 14-l10-16

lo-20

14-214-314-4

10-21 14-5

S-18 1010 Battery Voltage andCurrentS-IEi 1020 Battery Voltage andCurrentS-IV6 Stage Forward No. 1 BatteryVoltage, Current, and TemperatureS-IVB S tage Forward No. 2 BatteryVoltage, Current, and TemperatureS-IVB Stage Aft No. 1 BatteryVoltage, Current, and TemperatureS-IVB Stage Aft No. 2 BatteryVoltag e, rurrent, and Temp erature1U 6DlO Battery Parame tersIU 6D30 Battery Parame tersIU 6D40 Battery Parame tersS-IB Stage Heat Shield PressureS-18 Stage Flame Shield PressureS-16 Stage Heat Shield LoadingS-IB Stage Gase Drag CoefficientS-1B Stage Heat Shield Inner RegionTotal Heating RateS-16 Stage Heat Shield Inner RegionRadiation Heating RateS-IB Stage Meat Shield Inner RegionGas TempEratureS-I@ Stage Hear Shield Outer RegionGas TemperatureS-IB Stage Flame Shield TotalHeating RateS-10 Stage Flame Shield GasTemperatureS-IB Stage Flame Shield RadiationHeating dateVariation ot S-16 Flame ShteldRadiant H eating with Inboard EngineThrustComparison of S-18 Stage FlameShield Radiant Heating DataIU Sublimator Start Up Parametersfor Initial CycleIU TCS Coolant Control ParametersIU TCS Hydraulic PerformanceIU TCS GN2 Sphere Pressure(025-601)IU Inertial Platform Internal GasBearina GN:, Pressure

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11-5!l-611-711-811-1011-1111-1212-212-312-412-513-213-313-4

13-513-613-713-B13-10

13-1114-314-414-514-614-7

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LIST OF ILLUSTRATIONS (CONTINUED)

Figure Page14-6

14-i

14-e

15-r

15-215-3

A-l

A-2

A-3

A-4

A-S

A-6

A-?

A-8

A-9

iu GE5 Gt i: Sphere Pressure 14-B(DlO.GO3):,elected TU Ccmponent 14-9Temperatureshelected TU Component 14-IDTemperaturesM-208 Telem etry Ground 15-5Station CoverageSA-208 DP-1 Link RF Power Outpu t 15-6SA-2U8 C-Sand Acgufsition and 15-ELoss TimesSurface Ueather Map Approxi-mate ly 2 Hours Before Launchof SA-2C0/SL-4

A-2

500 Millibar Nap Apprcxim ately A-42 fiours Before Launch ofSA-2GB/SL-4Scalar Wind Speed a t Launch A-7Time of SA-2D8/SL-4Wind Direction at Launch Time A-9of SA-208/SL-6Pitch Yind Veipcity Component A- 10(W,) at ;sunch Tim e of SA-208/SL-4Vaw Wind Velocity Component A-li(Uz) at Launch Tim e of SA-2081

SL-4Pitch (Sx ! and Vaw (Sz) Component A-12blind Shears at Launcfl Time ofSA-20E/SL-4Relative Deviation of Temperature A-15and Pressure from the PM-63Reference ,Atmosphwe. SA-20&/SL-4Relative Deviation of Density and .4-16AhsoT ute Deviation of the Indewof Refraction from the PRA-63Reference Atmospnere. SA-2DB/SL-4

rii


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LIST OF TABLES

Table

i2-l2-22-33-14-l4-24-34-44-54-64-75-15-26-l6-26-36-46-56-6Y-1

7-27-39-l

9-?

5-3

Mission ObjectiveAcco1r~plish2ent.Summ ary of Failures andAnomaliesiinle 6dSe &lfllVd~ySiynificant Event Tim es>un:maryVariable Time and CmandedSwitch Selector EventsSA-iOU/Skylab-4 PrelaunchMilestonesTrack ing Data Sum;raryCompar;sonTrajectoryComparisonCorr;parisonComparisonImpact

S-IQ SpentEnvelopeComparisonConditions

of SignificantEventsof Cutoff Eventsof Separation Eventsof S-IB Spent StageStag? Impact

of Orbit InsertionS-IVU-208 Propellant DumpDeGrbit VelocityS-!VO-208 Impact DispersionLimitsS-IC rngine Start.Char,ictpristrcsS-I f? Individual EnginePropulsion PerfornlanceS-ID Stage Propellant IJsageCuto ff Level Sensor ActuationChdrdCtCriStiCSS-10 Stqe Propellant MassI!1 storyS-113 Fctuator MaxirwmPerformance UataS-iv0 Steady State Perforr.unce(STOV Open +60 Second TimeSlice at Standard AltitudeConditions)S-IV6 Stage 2ropellant MassHistoryS-JVLI APS Propellant ConsumptionSA-208 Inertial PlatfonVelocity ComparisonsNavigation Position an@Velocity Comparison (PACCS-12)SA-208 Boost Termina l ConditionsSA-208 Orbital Phase FlightProgram Attitude Cotmnands

PagexaiXXi

2-22-32-103-24-24-64-T4-74-104-104-115-l5-26-26-7

6-106-11

6-116-237.4

7-137-239-39-4

9-59-10

Table10-llC-210-311-l11-2

11-315-l15-215-315-415-516-116-216-316-416-516-6A-l

A-2A-3A-4

A-5

A-6

B-1B-2B-3

Liftoff Hisalignmen t SunaryMaximum Control VariablesOuring S-IB BurnMaximum Control VariablesDur'ng S-IVES First BurnS-IB Stage Battery PowerConsumptionS-l&S Stage Battery PowerConsumptionIIJ Battery Power ConsumptionSA-208 Measurement SumnarySA-208 Flight MeasurementsWaived Prior to FlightSA-208 Measurement Malfunctions$A-208 Launch Vehicle TelemetryLinks Performance SumarySA-208 IU CormlandsVehicle Masses (Kilograms)Vehicle Masses (Pcunds)Vehicle Yasse s (Kilograms)Vehicle Masses (Pounds)Fl iql Sequence WJS S SurmlaryMass Characteristics ComparisonSurface Observations at SA-208Launch TimeSolar Radidtion at SA-208 LaunchTime, Launch Pad 398Systems Used to Measure UpperAir Wind Data for SA-208Maximum Wind Speed in HighDynamic Pressure Region forSaturn Launch Vehic les 201through 208Extreme Wind Shear Valves in theHigh Qynamic Pressure Region forSaturn Launch VehiLle s 201 through208Selected Atmospheric Observationsfor Sat;rrn Launch Vehic les 201thro,jgh 208 at Kennedy SpaceCenter, FloridaS-IB Significan t ConfigurationChangesS-IVB Significan t ConfigurationChangesIU Significan t ConfigurationChanges

Page10-l10-610-1111-411-911-1315-215-315-315-415-1016-216-316-416-516-616-8A-3

A-S

A-6A-13

A-14

A-18

B-lB-2B-2

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ACKNOWLEDGEMENT

Tnis report is published by the Saturn Flight Evaluation Working Group,composed of representatives of Marshall Space Flight Center (KSFC),Kennedy Space Center, and MSFC's prime contractors, and in cooperationwith the Johnson Space Center. Significant contributions to the evalua-tion have been made by:

George C. Marshall Space Flight CenterScience and Engineering

Aero-Astrodynamics LaboratoryAstrionics LaboratoryComputation LaboratoryAstronautics LaboratorySaturn Program Office

John F. Kennedy Space CenterLyndon B. Johnson Space CenterChrysle CorporationMcDonnell Douglas Astronautics CompanyInternational Business Machines CorporationRockwell International CorporationGeneral Electric CompanyThe Boeing Company

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ABBREVIATIONS

ABACNAEAOSAPSARIA

ASAP

AS1AUXBDA

CDBCDDTCGCIFCMCPCPBCSMCYIDCSDODEBW

Base AreaAscension IslandEngine Exit AreaAcquisition of SignalAuxiliary Propulsion SystemApollo Range InstrumentedAircraftAuxiliary Storage andPlaybackAugmented Spark IgniterAuxiliaryBermudaBase Drag CoefficientCountdown Demonstration TestCenter of GravityCentral InstrumentationFacilityCommand ModulePressure CoefficientBase Pressure CoefficientCwrmand and Service ModuleCanary IslandDigital Command SystemDepartment of DefenseExplosive Bridge Wire

EC0ECS

EDSESTEMREMRCEPOESCFCCFMGBSGCSGDSGFCVGGGN2GRRHAWHEHzHSKHZI

Engine CutoffEnvironmental ControlSystemEmergency Detection SystemEastern Standard TimeEngine Mixture RatioEngine Mixture Ratio ChangeEarth Parking OrbitEngine Start CommandFlight Control ComputerFrequency ModulationGas Bearing SystemGuidance Cutoff SignalGoldstoneGOX Flow Control ValveGas GeneratorGaseous NitrogenGuidance Reference ReleaseHawaiiHeliumHydmgenHoneysuckleHertzInclination

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AB3REVIATIONS (CONTINUED)

IAPXIBMICDIECOIGMIUJSCKSCKWJL"2LOSLOXLSALUT

LVDC

MADManfMAX QMCC-H

MILA

Power Transfer TestInternational BusinessMachinesInterface Control DocumentInboard Engine CutoffIterative Guidance ModeInstrument UnitJohnson Space CenterKennedy Space CenterKwajaleinLiquid HydrogenLoss of SignalLiquid OxygenLevel Sensor ActuationLaunch Umbi 1 cal TowerLaunch VehicleLaunch Vehicle Data AdapterLaunch Vehicle DigitalComputerMadridManifoldMaximum Dynamic PressureMission Control Center -HoustonMerritt Island Launch Area

Misc. MiscellaneousML Mobile LauncherMOV Mair Oxidizer ValveMR Mixture RatioMSFC Marshall Space Flight CenterP, NO. NumberNASA

NPSHNPSPOATOECOOMPTOTOTBVows

Oxid.

PAPACSS

PBPCMPEAPWA

National Aeronautics andSpace AdministrationNet Positive Suction HeadNet Positive Suction PressureOverall TestOutboard Engine CutoffObserved Mass Point TrajectoryOperational TrajectoryOxidizer Turbine By-,Pass ValveOrbital Workshop (ModifiedS-IVB Stage)Oxidizer

Ambient PressureProject Apollo CoorainateSystem StandardBase PressurePulse Code Modulat ionPlatform Electronics AssemblyPrinted Wiring Assembly

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AGGREVIATIONS (CONTINUED)

PressPSDPTCS

PLIQtr.9RRDSM

RFRF1RLH

S/ASACSSCSCFk!

SC Jli?

SLSLA

SMSrefSVsws

PressurePower Spectral DensityPropellant TankingComputer SystemPropellant UtilizationQuantityDynamic PressureRadiusRemote Digital SLY-MultipleRadio FrequencyRadio Frequency InterferencePetrograde Local Horizontal

Service ArmService Arm Control SwitchSpacecraftStandard Cubic Feet perMinuteStandard Cubic InchesPer MinuteSkylabSpacecraft Lunar ModuleAdapterService ModuleReference AreaSpace VehicleSaturr Workshop

TANTBTCS

TEXTMTVCUCRusUTVABvWLPhOT

TananariveTime BaseTerminal Countdown Sequenceror Therm21 Conditioning SystemCorpus Christi, TexasTelemetryThrust Vector ControlUnsatisfactory Condit ion ReportUnited StatesUniversal TimeVertical Assembly Bui ldingVelocityWallops IslandDescending NodePath Angle

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SA-208 MISSION PLAN

The Saturn IP $A-208 (SL-4 Launch) is to place the Comand and ServiceModule (CSM-118) in a 150 x 224 km 81 x 121 n.mi.) orbit coplanarwith the orbiting Saturn Work Shop I SW). SA-208 is comprised of theS-16-8, S-IVR-208, and Instrmmt Unit (IU)-207. This is the thirdand final manned flight of the Skylab Program.Launch is scheduled to occur on the 16th of Novtir 1973 from LaunchComplex 39, Pad B of the Kennedy Space Center (KSC) at 9:Ol a.m. EasternStandard Time (EST). Flight will be along an azimth dependent onlaunch time. The nominal flight azimuth will be 53.781 degrees measuredeast of north. The launch window duration is 13 minutes. Vehicleweight at ignition is nominally 594,214 kg (1,310,021 lbm).The S-18 stage powered flight will last approximately 141 seconds. TheS-IV8 stage will provide powered flight for approximately 434.7 secondsinserting the CSM into a phasing orbit for rendezvous with the orbitingsws. Then the S-IV8/IU will separate from the CS?LOn the fourth revolution, residual S-IV8 stage propellants will be drnpcdthrough the J-2 engine to produce a &orbit Illpulse. By controllingvehicle attitude, and time and duration of propellant w, the spentS-IVB/I'J will be directed towards inplct In an bland-free area of thePacific Ocean.After rendezvous, the crew will transfer fnr the CSM to the SUS to per-form the on-orbit scheduled misslon actfvities. These l ctiviths cur-rently call for inhabiting the SWS for a naximm period of 84 days.After campletiun of these activities. the SUS will be prepared for longduration orbital storage. The crew will transfer to the CSM and theSUS will be left in a solar inertial attitude. The CSH rtiii undo&and deorbit for m-entry.


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FLIGHT SUfWARY

The space vehicle was laubiched at 09:01:23 Eastern Standard Time (EST)on 16 November, 1973 from pad 398 of the Kennedy Space Center (KSC),and placed the Comnand Service Module containing three crew members intoearth orbit for rendezvous with the orbiting Saturn Work Shop. The per-formance of ground systems supporting the SA-208/Skylab-4 countdown andlaunch was satisfactory. Some concern was expressed during prelaunch count-down about stress-corrosion in the launch vehicle. The launch was re-scheduled from a November 10, 1973 date to replace all eight fins on theS-IB stage after post Countdown Demonstration Test inspections revealedcracks in the fin attachment fittings.The vehicle was launched on an azimuth of 90 degrees east of north. Aroll maneuver was initiated at approximately 10 seconds that placed thevehicle on a flight azimuth of 53.781 degrees east of north. The downrange pitch program was also initiated at this time. The reconstructedflight trajectory (actual) was very close to the Post Launch PredictedOperational Trajectory (nominal). The S-IB stage Outboard Engine Cutoff(OECO) was 0.31 seconds later than nominal. The total space-fixed velocityat this time was 0.82 m/s greater than nominal. After separation, theS-IB stage continued on a ballistic trajectory until earth impact. TheS-IVB burn terminated with guidance cutoff signal and was follti byparking orbit insertion, both events being 2.17 seconds earlier than naninal.An excess velocity of 0.73 m/s at insertion resulted in an apogee 2.84 kmhigher than nominal. The parking orbit portion of the trajectory from in-sertion to Ccmznand and Service Module/S-IVB separation was close to nominal.The crew-initiated separation of the CSM from the S-IVB stage occurred20.45 seconds later than nominal.All aspects of the S-IVB/XU deorbit ware accomplished successfully. Thepropellant dump was performed as planned with impact occurring in theprimary disposal area. honeysuckle confirmed that the vehicle was safedfollowing the propellant dump. Although breakup occurred after loss ofsignal at Kwajalein, BeparWnt of Oefenre sources confinned the deorbit.The S-IB stage propulsion system perfornrance was satisfactory throughoutflight. Stage longitt. : site thrust averaged 0.13 percent lower thanpredicted. Stage LOX, fuel, and total flour&es averaged 0.10 percent,0.18 percent, and 8.13 percent 1-r than predicted, respectively. Stagemixture ratio averaged 0.08 percent higher than predicted. Stage specificimpulse was within 8.04 percent of predicted. Inboard Engine Cutoff (MO)occurred at 137.82 seconds (O-16 seconds earlier than predicted). OEC8occurred 3.47 seconds after IfC8 at Ml.29 seconds. OEC8 was inltfated byLOX starvation, as planned, At OECO, the LOX residual was 2925 WI c-redto the predicted 3287 lbm, and the fuel res'ddual was 6878 I#MI compared tothe predicted 5989 lbm. The stage hydraulic system perfomd satisfactorily.

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na S,-:i'E propulsion system performed satisfactorily throughout the opera-tional phase of burn ard had norn;a? start and cutoff transients. S-IVBbiiri; time was 432.22 seconds, 2.46 seconds shorter than predicted for theactual flight azimuth af 53.8 degrees. This difference is composed of-0.07 second due to S-ID/S-IVl3 separation velocity, orbital radius, andweight and -2.33 seccnds due to higher than predicted S-IVB performance.The ehoine performance dur'ng burn, as determined from standard altitudereconc;rlIrTion analysis,-. __b deviated from the predicted Start Tank DischargeVal ve (STDV) open +O? second time slice by +Q.20 percent for thrust.Specific impulse was as predicted. The engine control system performedL z ibv


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The structural loads experienced during the SA-208 flight were well belowdesign values. The maximum bending moment was 10.3 x 106 in-lbf (approxi-mately 18.5 percent of design) at vehicle station 942. The S-I8 thrustcutoff transients experienced by SA-208 were comparable to those of theSA- 207. The S-IY5 engine cutoff transients did not produce the 55 Hz oscil-lations noted on the SA-207 flight. All vibration and pressure oscillationswere nominal during the entire launch and there was no indication of anyPOCO instability. The maximum ground wind experienced during the prelaunchperiod was 21 knots and during launch was 7 knots. Both values were wellbelow the allowable limits. There was no evidence during flight of anycompromise af structural integrity due to either the prelaunch RP-1 tankbulkhead reversal or the stress corrosion incidents associated with the S-15E-Beam, S-15 fin rear spar fitting, and S-IS/S-IVB interstage reaction beam.The stabilized platform and the guidance computer successfully supportedthe accomplishment of the SA-208 Launch Vehicle mission objective. Targetedconditions at orbit insertion were attained with insignificant error. Noanomalies nor deviations from nominal performance were noted. The stabilizedplatform indicated unplanned velocity changes between 3440 and 5735 seconds.The control and separation systems functioned correctly throughout thepowered and coast flight of SA-208. Engine gimbal deflections were nominal.Bending and slosh dynamics were adequately stabilized during boost flight.Separation dynamics were normal.The electrical systems and Emergency Detection System (HIS) of the SA-208launch vehicle performed satisfactorily during the flight. Battery perform-ance (including voltages, currents, and temperatures) was satisfactory andremained within acceptable limits. Operation of all power supplies, inverters,Exploding Bridge Wire (EBW) firing units, and switch selectors were nerninal.During the countdown at T minus 75 minutes, an out-of-tolerance indicationterminated the Instrument Unit (IU) internal power test by switching powerto external.Base pressure data obtained from SA-208 have been compared with preflightpredictions and/or previous flight data and show good agreement.Data from the seven SA-208 S-18 stage base thermal taeasurents have beencompared with corresponding data from the flights of SA-203 through SA-207.These comparisons indicate an Sk-208 base region them1 enviromnt ofcomparable magnitude, with the flame shield radiant data trend beingsimilar to that recorded on SA-207. Al? measured thermal enviromnt datawere well below S-IB stage design levels.The S-IB stage engine compartment and instrument comparwnt require environ-mental control during prelaunch operations, but are not actively controlledduring S-IB boost. The desired temperatures were maintained in both coopart-merits durinSystem (ECS 4

the prelaunch operation. The ?U stage Environarental Controlexhibfted satisfactory perfor~nce for the duration of the IUmission. Coolant tetnperatures. pressures ) and flr#rates were continuouslymaintained within the requtred ranges and design ?iaits.

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The vehicle data systems performed satisfactorily except for a problemwith the IU DP-1 telemetry link. This problem resulted in the loss ofsome IU and S-IV8 data, but sufficient data were recovered to reconstructall important flight information and to provide real time mission support.The overall measurement system reliability was 100 percent. The usualtelemetry interference due to flame effects and staging was experienced.Usable telemetry data were received until 20,480 seconds (05:41:00). Goodtracking data were received from the C-Band radar, with Kwajalein (KWJ)inidcatin final Loss of Signal (LOS) at approximately 21,180 seconds(05:53:00.. s The Sec;rre Range Safety Cbmnand Systems on the SIB and S-TVSstages were ready to perform their functions properly, on cOrmMndr ifflight conditions during launch phase had required destruct. The DigitalCommand System (DCS) performed satisfactorily from liftoff through deorbit.In general, ground engineering camera coverage was good.Total vehicle mass, determined from post-flight analysis, was witi;.n 1.47percent of predicted frum ground ignition through S-IVB/spacecraft separation.Hardware weights, propellant loads and propellant utilization were closeto predicted values during flight.The SA-208/Skylab-4 space vehicle on the third visit to the Saturn Work Shop(SWS), was manned by Lieutenant Colonel Gerald P. Carr, Coasnander; DoctorEdward D. Gibson, Science Pilot; and Lieutenant Colonei William R. Pogue,Pilot. The Command and Service Module (CSH) was inserted into earth orbitapproximately 9 minutes and 47 seconds after liftoff. The orbit achieved was227.08 by 150.10 kilometers. Stationkeeping with the SUS began approximately7.5 hours after liftoff. A hard dock was achfeved at approxfmately 8 hoursafter liftoff following two unsuccessful docking attempts. Activation ofthe SWS was accomplished during visit days 2 through 4.Undocking, CSM deortit, and comrwnd module landing is planned for visit day85, February 8 at 2C:lS:OO UT in the Pacific Ocean, southwest of San Dlego,California.

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MISSION OBJECTIVES ACCoMpLISMENT

Table 1 presents the MSFC Launch Vehicle objective for Skylab-4 asdefined in the "Saturn Mission Implementatbon Plan SL-I/SA-208, HSFCDocument PM-SAT-8010.24, Revision A, dated July 20, 1973. An assess-ment of the degree of accomplishnmt can be found in other sections ofthis report as shown in Table 1.

Table 1. Mission Objective Accomplishment *FzEE SECTIONNO. LAUNCH VEHICLE OBJECTIVE DSSCNE- IN HHICHi$kNT PAWES DISCUSSED/1 Launch and insert a manned CSH into Cmplete Hone 4.2the earth orbit targeted for duringthe fIna launch countdown. [SL-4was targeted for an 81 x 121 n.mi.(150 x 224 km) orbit].i


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FAILURES AND IRNOMC\LIES

Evaluation of th; launch vehicle and launch vehicle ground supportequipment data revealed the following five anomalies, none of whichare considered significant.

Table 2. Sumnary of Failures and Anomalies


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SECTION 1INTRODUCTION

1.1 PURPOSE

This report provides the National Aeronautics and Space Administration(NASA) Headquarters, and other interested agencies, with the results ofthe SA-208 launch vehicle flight evaluation (Skylab-4 launch). Thebasic objective of flight evaluation is to acquire, reduce, analyze,evaluate and report on flight data to the extent required to assurefuture mission success and vehicle reliability. To accomplish thisobjective, actual flight problems are identified, their causes deter-mined, and recommendations made for appropriate corrective action.1.2 SCOPEThis report contains the performance evaluation of the launch vehiclesystems with special emphasis on problems. Sumnaries of launch opera-tions and spacecraft performance are included.The official George C. Marshall Space Flight Center (MSFC) position attnis time is represented by this report. It will not be followed by asimilar 1.eport unless continued analysis or new information shouldprove the conclusions presented herein to be significantly incorrect.1.3 PERFORMANCE PREOICTIONS BASELINEUnless otherwise noted, all perforn!ance predictions quoted herein forcomparison purposes are those used in or generated by the Skylab-4(SA-208) Post Launch Predicted Operational Trajectory (OT) S&E-AERO-MFP-162-73, dated November 28, 1973.

l-l/1-2


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SECTION 2EVENT TIMES

2.1 SUWARY OF EVENTSRange zero occurred at 09:01:23 Eastern Standard Time (EST) (14:01:23Universal Time [UT]) Noverr,Ser 16, 1973. Range time is the elapsedtime from range zero, which, by definition, is the nearest wholesecond prior to iiftoff signal, and is the time used tiWoughWt thisreport unless otherwise noted. Time from base time is the elapsedtime from the start of the indicated time base. Table 2-l presents thetime bases used in the flight sequence program.The start of Time Bases TO and Tl were near nominal. T2 and T3 wereinitiated approximately 0.2 second early and 0.3 second late, respectively.These variations are functions of S-15 stage cutoff times discussed inSection 6 of this document. Tq was initiated 2.2 seconds early, consistentwith the early S-IV5 engine cutoff discussed in Section 7. Start of TS wasinitiated by the receipt of a ground colnrand. 1.9 seconds earlier thanscheduled as discussed in Section 5.2.Figure 2-1 shows the difference between teler&ry signal receipt at aground station and vehicle (Launch Vehicle Digital Cmuter [LVDC]clock) time. This difference between ground and vehicle time is afunction of LVDC clock speed.A sunrmary of significant event times for SA-ED8 is given in Table 2-2.The preflight predicted times were adjusted to match the actual firstinotion time. The predicted times for establishing actual minus pre-dicted times in Table 2-2 were taken fran 68MWoOlC, "Interface ControlDocument Definition of Saturn SAG07 and Subs Flight Sequence Program"and fran the Skylab-4 (SA-208) Post Launch Predicted Operational Tra-jectory (OT) S&E-AERO-MFP-162-73, dated November 28, 1973, unless other-wise noted.2.2 VARIABLE TIME AND C-ED SUITCH SELECTOR EVENTSTable 2-3 lists the switch selector events which were issued during theflight, but were not progr& for specific times.

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Table 2-l.: 1 Time Base SumnaryUNGE TI?lETIME BASE SECONDS SIGNAL START

To -16.954 Guidance Reference ReleaseTl 0.471 IU Umbilical Disconnect Sensed by LVDCT2 134.839 S-IB Lok Level Sensors Dry Sensed by LVDCT3 141.287 S-IB OECO Sensed by LVDCT4 577.379 I S-IVB EC0 (Velocity) Sensed by LVDC

18,637.674 I Initiated by Receipt of Ground Comnandl2-

30 -.

01 I I I 4D 5,000 10,000 15,000 20,000RANGE TIME, SECONDS* I I I LD 1:oo:DO 2:OD:oo 3:OO:o0 4:oo:oo 5:oo:oo

RANGE TIME o HOURS:MiNUTES:SECONDS* RANGE TIME OF GROUND RECEIPT OF TELEMETERED SIGNAL FROM VEHICLE

l * RANGE TIME OF OCCURENCE AS INDICATED BY UNCORRECTED LVDC CLOCKFigure 2-l. LVDC Clock/Ground Time Difference

2-2


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CPNbE TIME TlMEI lf l f vt..l i )t \ cr IPT i(! *

5F. c 5tC SEC SEC

1 c ,lllO8brCt itftntbLt +ti.fA bt -17.i) -0. I -17.4 0.0l,c)C)

? L-lb4 th(, I~Jt 5lA1 L!!PM ,$? - 3. A -0.1 -3.5 0.07 t-li STAt.1 ill,hAL t* IbI~Jt &LO. 7 -3. z -0.1 -3.4 0.0.c -1r 514~~ 5lkdL.L thcT I1t JLJ. L,5 c -10 il8~1 \llT .AL tth( .I.t h

-3.0 -0.1 -3.4 0.0,,:. -2.u -0. i -3.3 0.0

6; -1R s74ri ~l(JJAC thlillrt 40. r( -2.v -c. I -3.3 0.07 b-b SlAsl 5ll.N~~ t%uC,*~f .(I . / -r.r -0.1 -3.2 0.0 I- 16 ST4W T ,llbNAL thC.INt NO. . -.c( -0.1 -3.2 0.n9 k-lti 514n1 bI(,hAc thc-,lw IVlJ. 3 -2. ! 4.1 -3.1 0.0

I 0 -I+ ! STA VT \iL-N&C tNt~iNt cl,,. 1

i I*51 WT!U N

-r.7 -n. 1 -3. I 0.0Ii 4PJuGt :f YV n . 0 -4.512 li. 3 0.0 -0.2 0.0i3 lU UHdiLlC4L ~Ji\CUNWtCT. \lAt iT

I 1NGl.t tNG l~t. CulOFF tNAnLt

0.5 0.0 0.0 0.0OF lI*? t!A bt 1 (111If Tut F

14 3.4 -0.1 3.0

I t(.iN PITCW . YAr ANU WOLL

0.015 01 JAW. Pb!L5> u*iZ~liUh 6.4 -0.1 6.0 cl.0ShllTC Iff VPLVt 5 CLUSEI6 10.3 -0.5 9.9 -0.4

n4Nt UVtk17 1 LJLTlPit thblkt CUT Off th4bLt in.4 -0.1 10.0 0.0l lid .ULTlPLE t%blNt CUlOfF th4bLt 10.5 -0.1 10.1 0.00219 tLErtlfr CALIWA~~ oh 20.4 -G. 1 20.0 0.0

20 ELLMtTEc( CALitjH ATt Ufr 23.4 -0.1 25.0 0.0di ELE-ET rtV C4L1a;UATW IbfLlGH T 2T.4 -0.1CALIU*4lt Oh 27.0 0.0

22 rtLteTa v c4~1nwa~ov lh-F ~[Gt iT 32.4ALIHUAT~ off -0.1 32.0 0.0

23 .AUNCn VEnICLE ENGlNtS EOS 40.4UTO f F tN4tlLE -0.1 40.0 0.0

2-3


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REpRc~)l~UClBII,I?I OF THE()RIc;ISX, PAGE Is IdOK.

Table 2-2. Significant Event limes Sumnary (Continued)

40.4 1.4 44.0 1.55G.5 al. I S9.0 0.1hY.5 -6.0 by.0 -4.9

3~ EaCCSS RrTE (r.YvH l 4uTu-4tlCnT 120.3 -0.1 128.9 0.0Ihr~ltilT LkD SbuITCh v4TtGYRO5 SC IWICAT~W &

3V S-It TrC


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Table 2-2. Significant Event Times Sumnary (Continued)

L4GE E%r flUIN UNIT> HtiSETCIGE roToRs xGw1110~ 4wl

JtTTXSON WELIVS RtSET,T-EKnrNGEW c)VPISS Y4LVECONTuM LNIWE

C4CIMU4Tf 6,N

POINT NO. 5

26


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Table 2-2. Significant Event Times hmnary (Continued)TWE caon BASE

ITEM EVENT OESCHIPTIOY vSEC SEC SEC SECtic) TtLEM ETvY CPLIt.w4TUk Ir*FLIGHl 4Yb.7 0.3 3ss.4 0.0

CILIbPArE Oh~9 TELEMETRY ~4~ItbfrTw Iruv~1G~l 499.9 -1.5 XI).6 -1.090 PYOPELL~N T OLPLCT IUrU CUTW-F 561.3 0.3 400.0 0.0

4QU91 MGIN TEw MI?,~ L GUID4%Ct 553.0 -4.0 411.7 -4.3~2 GllIDn!uCE CUT OFF 51ch4L t(rCSb 577.ld -2.17 43s.ea -2.49

ECU93 S-1vn SOLtfvOlO nCTlv4fIohi 577.2 -2.3 435.9 -2.6

SiGh4Lv4 Sf4YT LIF Tlkt b4SL 4 (141 s77.4 -2.2 0.0 0.095 5-IV8 M4liuST4GE OK P*tSSUl)t 577.4 -2.3 0.0 -o* I

SUITCH UHOPOul 01or, 02 577.4 -2.3 0.0 -0.1

IhrERTI4L 4TTlTuDf FutELE97 S-:Va ENGINE CUT OFF hrO* 1 UN 577.5 -?.2 0.1 0.098 SIVC) tNGINE CUTOFF NO. 2 ON 577.6 -2.2 0.2 0.099 ruEv4LvfS CLOSE 577.7 -2.2 0.3 0.0

100 ,OI TIN K wPV VILVE WEN ON 577.9 -2.3 0.6 0.0ST4ctT LOU VEtuf101 -04 t4Nr( PRESSWILATIO~ SMUT- 570.1 -2.3 0.0 0.0ffc W4LV ES CLOSE ON102 LOIt TINK FLIGHT PWSS SYSTW 578.3 -2.3 1.0 0.0Off103 $~:,~I DEPLETION CUToe 579.1 -2.3 1.0 0.0

104 S-IV& MIRlMrL nrr1r, CO~TUOL 579.6 -2.2 2.2 0.0V4LVE CLOSE10s s-IVB Ri4fUW RITIO CONTWOL 579.7 -2.3 2.4 0.0V4LUk ercnue CLOSE106 FL1Gn T CONWOL CWPUTCR S-iv(, so0.e -2.3 3.5 0.0NUN WWE Wf 4107 FLIGHT CONTWL CulluUTfm S-Ivy 581.0 -2.3 3.7 0.0BUUN ROM OFF 'I'100 bU4 HVM14lkIC PW CLiGwT WOE -1.2 -2.3 3.9 0.0OFF

2-7


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- ..iZI i

Table 2-2. Significant Event Times Sumary (Continued)

2-8 .


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Table 2-2. Significant Event Times Sumnary (Continued)

VALVE WEM OF F (LrUD LOX UUMP)135 FNCINE HE CONTROL VALVC 19ltb.3 8.1 530.5 9.9OPEN ON (Sl4kf MZ IWMP,136 STIR1 SEOliEIuCE c 19i?bi?.3 -9.9 624.6 1.0STOP Hi? DUMP .SlWf SIVli srttlufi131 S-1V9/IU IHPACT Zl71hO 12t.t 3074.3 129.b

2-9


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Table 2-3. Variable Time and Commanded Switch Selector Events

%F TMFUKTION STAGE (SEC) 6AS~EC) ~REMRUSTelemetry Callbrator Ill 660.691 T4 + 63.312 Bcmda Revolutlom 1In-Flight CalibrateonTM Calibrate On f-Iv9TN Calibrate Off S-Iv5Telemetry Calibrator IUIn-Fllght Callbrrteoff

663.691 T4 + 85.312 '* " =664.692 T4 l 4,313' 'i !( a665.699 T4 + a.320 .I 'I 'I

Telemetry Calibrator IUIn-Flight Calibrateon1214.710 T4+ 667.331. Mrld Revolution 1 .

TM Calibrate On S-IV6 1247.720. 14 + 670.341 " " "TM CalIbrrk Off s-199 1269.726 14+ 671.347 " m .*Telemetry Clllbrator IU 1249.710 14+ 672.331 I I .In-Flight QllbNkoffm CdlbNtor Iu 6716.716 i4+ 6136.337 Madrid Rwolutlan tIn-Flight CalibrateonTM CallbraG On s-199 6719.717 T4+ 6142.336 l I ITn kllbrrta Off S-XVI 6729.710 14 l 6143.336 m * bTeleaetrp CallbNDr IU 6721.717 T4+ 6111.336 l *In-Flight Callbrrteoff.Uater Coolant Value IU 6760.175 T4 l 6766.175 LVEFunctlonTel-try Callbrrtor IU 10960.765 T4+16403.386 6olQtom Rcrolutlon 2In-Flight hltbr8konTN Callbrak QI s-Iv9 10993.766 T4+10466.377 l . .m kllbNt@ otf s-m 109w.766 T4 + 10407.377 . I Ifelmtty CllibNtOr IU lom5.765 14 + 1om.a6 r . IIn-Flight hlfbr8hoff

2-10


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Table 2-3. Variable Time and Commanded Switch Selector Events (Continued)

FUNCTIONTelemetry CalibratorIn-Fllght CalibrateonTM Cdllbrdte OnTh! Calibrate Of fTelemetry Cdl lbratorIn-Fllght CallbrdteOf fTelemetry CdlibrdtOrIn-Flight CallbrateOnTM Calibrate OnTM Cdlibrdte OfiTelemetry CalibratorIn-Flight CalibrateDffTelemetry CallbratorIn-Flight CalibrateDnTM Calibrate OnTN Calibrate Of fTel-try Cdl IbratorIn-Flight CdlCbrdteOf fTelemetry CalibratorIn-Fllght CalibrateOnm Cdllbrdte OnTfJ Callbrdte OffTR CalibratorIn-Fllght CalibrateOf f

STAGEIU

s-IVBs-IVBIU

IU

s-IVBs-IVBIU

IU

s-IVBS-IV8IU

IU

s-IVBS-IV6IU

___--RANGETIME(SEC)

12252.729

12256.72912257.72812257.05

14756.761

14759.75014760.75014761.750

15948.761

15951.7661' 952.7611' 953.05

1 748.807

17751.77417752.782(17753)

TIMEFROMBASE (SEC)T4 + 11675.350

T4 + 11679.349T4 + 11680.35tIT4 + 11679.68

T4 + 14179.382

T4 + 14182.371T4 t 14183.371T4 l 14184.371

T4 + 15371.382

T4 + 15374.387T4 + 15375.382T4 + 15375.67

T( + 17731.835

T4 + 17734.820T4 + 17735.028

REMRRSNadrld Revolution 3

TMDmpout.Timed FromCaRpressed DataHoneysuckle Revolutlon

Hawall Revolution 3

II .

II .

TNDropout,Timd FromCornpressedData

l

l

t+

l Telemetry dropout caused data processin problems. These camands were received byCYI Rev. 4 and are shown wlth the sam Gmund Range Tlmt as In Table 3-3.l * This camand occurred at a time when the quality of the data received was so poorIt was not processed.

2-11/2-12


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SECTION 3LAUNCH OPERATIONS

3.1 SUMMARYThe space vehicle was launched at 09:01:23 Eastern Standard Time (EST)on 16 November, 1973 from pad 39B of the Kennedy Space Center (KSC),Saturn Complex. Damage to the pad, Launch Umbilical Tower (LUT) andsupport equipment was considered minimal.The performance of ground systems supporting the SA-208/Skylab-4 count-down and launch was satisfactory. Some concern was expressed duringprelaunch countdown about stress-corrosion in the launch vehicle. Thelaunch was rescheduled from a Ncvember 10, 1973 date to replace alleight fins on the S-IB stage after post Countdown Demonstration Test(CDDT) inspections revealed cracks in the fin attachment fittings.3.2 PRELAUNCH MILESTONESA chronological sumnary of prelaunch milestones is contained in Table 3-l.The fuel tank damage problem is discussed.in paragraphs 3.4.1 and 8.3.1.The stress corrosion problem is discussed in Paragraph 8.3.2.3.3 TERMINAL COUNTDOWNThe SA-208/Skylab-4 terminal countdown was interrupted to allow for removaland replacement of the S-IB fins (see paragraph 3.4.1). The countdorm wasresumed on 14 November with the space vehicle countdown start at T-42.5hours. Scheduled holds were initiated at T-3 hours 30 minutes for a dura-tion of 60 minutes and at T-15 minutes for a duration of 2 minutes. Duringthe countdown power transfer test (IAPX) the IU internal power was automati-cally returned to external indicating an out-of-tolerance IU Power measure-ment. The IU console engineers verified acceptable IU internal power condi-tions by manual tests immediately after the IAPX test was completed. Thepower transfer by terminal countdown sequencer at T-50 seconds was accom-plished smoothly and no countdown delay was experienced (see paragraph 11.4.1).The space vehicle was launched at 09:01:23 EST on 16 November, 1973.3.4 PROPELLANT LOADING3.4.1 RP-1 LoadingThe RP-1 system successfully supported countdown and launch. Fuel wasinitially placed onboard the S-IB stage October 23, 1973. During anonnal gravity drain to the 600-inch level, the bulkheads were subjectedto a negative pressure because the vent covers had not been removed.

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Table 3-1. SA-208/Skylab-4 Prelaunch MilestonesDATE ACTIVITY OR EVENT

November 4, 1971 S-IVB-208 Stage ArrivalJune 12, 1973 Instrument Unit (IU) S-IU-207 ArrivalJune 20, 1973 S-IB-8 Stage ArrivalJuly 31, 1973 S-IB Erection on Mobile Launcher (K)-1July 31, 1973 S-IVB ErectionAugust 1, 1973 IU ErectionAugust 4, 1973 Launch Vehicle (LV) Electrical Systems TestCompleteAugust 14, 1973August 20, 1973

LV Transfer to Pad BLV Propellant Dispersion/Malfunction OverallTest (OAT)

August 22, 1973August 30, 1973October 11, 1973October 23, 1973October 25, 1973November 2, 1973

SV OAT 1 (Plugs In)Space Vehicle (SV) Electrical MateSV Flight Readiness Test (FRT) CompleteRP-1 Loaded (forward fuel tank bulkhead damage)S-IB Fomard fuel tank bulkhead r-e-formedCountdown Demonstration Test (CDDT) CompletedNetI

November 7, 1973 RP-1 Drain (for fin replacement)November 13, 1973 S-IB Fin Replacement CompleteNovember 14, 1973 RP-1 ReloadedNovember 14, 1973 Launch Countdown BegunNovember 16. 1973 SL-4 Launch

3-2


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This resulted in iocai fzed curvature reversal of the upper bulkheads of tanksF3 and F4. The bulkheads were returned to flight-worthy configuration byapplying a positive pressure to the fuel u?lage (see paragraph 8.3.1). OnNovember 7, 1973 the fuel wbs drained from the S-IB stage to reduce the loadon the fins to allow their removal and replacement (see paragraph 8.3.2).Fuel was again placed onboard the S-IB stage November 14, 1973. Tailservice mast fill and replenish was accomplished at T-8 hours and leveladjust/line inert at about T-l hour. Both operations were completedsatisfactorily as planned. Launch countdown support consumed 41,522gallons of RP-1.The fuel temperature was monitored during the launch countdown and atT-l hour, a final fuel temperature of 57OF was projected to ignition.The final fuel density was obtained using the projected temperature.When the fuel level was raised to the overfill sensor level 8-l/2 hoursprior to launch, the Propel1 ;zt Tanking Computer System (PTCS) mass readoutindicated no error in the fuel reight.the final PTCS number. No error correction was required to

3.4.2 LOX LoadingThe LOX loading system successfully supported countdown and launch. Thefill sequence began with S-IB chilldown November 16 at 12:42:00 A.M. ESTand was completed 1 hour 50 minutes later with all stage replenish. Re-plenish was automatic through the Terminal Countdown Sequencer (TCS) with-out incident. LOX consumption during launch countdown was 133,000 gallons.

LOX was reported emanating occasionally fror the four outboard tank ventvalves during the countdown. The magnitude and frequency of these dis-charges were considered to be less than those observed during the count-down of SA-207.The LOX vent valves were closed for three periods during the countdownto preclude the possibility of safety hazards to personnel from LOX dis-charges. Each of the three vent closure periods was approximately twominutes in duration.3.4.3 LH2 LoadingThe LH2 system successfully supported countdown and launch. The fillsequence began at 02:20:22 EST and normal S-IV8 replenish was establishedat 03:15:28 EST. Replenish was nominal and was terminated at the startof terminal countdown sequence. Launch countdown support consumed about125,000 gallons of LH2.

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3.5 GROUND SUPPORT EQUIPMENT3.5.1 Ground/Vehicle InterfaceIn general, performance of the ground service systems supporting allstages of the launch vehicle was satisfactory. Overall damage to the pad,LUT, and support equipment from blast and flame impingement was consideredminimal. Detailed discussicn of the Ground Support Equipment is containedin KSC Skylab/Saturn IB (SA-208) "Ground Support Evaluation Report'.The Propellant Tanking Computer Systems (PTCS) adequately supported allcountdown operations and there was no launch damage.The Environmental Cc:trol System (ECS) performed satisfactorily throughthe countdown and launch. Changeover from air to GN2 occurred at 23:56:00EST on Novetier 15, 1973.The Service Arm Control Switches (:ACS) satisfactorily supported SL-4countdown and launch. Readjustment was required after S-IB fin replace-ment. Launch damage was minimal.The hydraulic charging unit and service arms lA, 6, 7 and 8 satisfactorilysupported the SL-4 countdown and launch. Performance was nominal duringterminal count and liftoff.The damping systems supported the countdown and launch. There were nosystem failures.The 3igital Event Evaluator -3 and -6 systems satisfactorily supported allcountdown operations. There was no system damage.3.5.2 MSFC Furnished Ground Support EquipmentAll ground pawer and battery equipment supported the prelaunch operationssatisfactorily. All systems performed within acceptable limits. Thehazardous gas detection system successfully supported SL-4 countdown.

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SECTION 4TRAJECTORY

4.1 SUMMARYThe Skylab-4 vehicle was launched at 09:01:23 Eastern Standard Time(Range Zero), November 16, 1973, from Pad 398 at Kennedy Space Center.The vehicle was launched on an azimuth of 90 degrees east of north. Aroll maneuver was initiated at approximately 10 seconds that placed thevenicle on a flight azimuth of 53.781 degrees east of north. The downrange pitch program was also initiated at this time.The reconstructed flight trajectory (actual) was very close to the PostLaunch Predicted Operational Trajectory (nominal). The S-IB stage Out-board Engine Cutoff (OECO) was 0.31 seconds later than nominal. The totalspace-fixed velocity at this time was 0.82 m/s greater than nominal. Afterseparation, the S-IB stage continued on a ballistic trajectory until earthimpact. The S-IVB burn tenoinated with guidance cutoff signal and was fol-lowed by parking orbit insertion both 2.17 seconds earlier than nominal.An excess velocity of 0.73 m/s at insertion resulted in an apogee 2.84 kmhigher than nominal.The parking orbit portion of the trajectory from insertion to Commandand Service Module (CSM)/S-IVB separation was close to nominal. The crew-initiated separation of the CSM from the S-IVB stage occurred 20.45 secondslater than nominal.4.2 TRAJECTORY EVALUATIONThe standard coordinate systems used in the following paragraphs are definedin S&E-AERO-MFT-10-74, "SL-4 (SA-208) Launch Vehicle Postflight Trajectory".4.2.1 Ascent Phase

The ascent phase spans the interval from guidance reference releasethrough parking orbit insertion. The ascent trajectory was establishedfrom telemetered guidance velocity data and tracking data from five C-Bandstations and one S-Band station listed in Table 4-l. Approximately 2 per-cent of the tracking data was rejected due to inconsistencies. The initiallaunch phase trajectory (from first motion to 20 seconds) was establishedby a least squares curve fit of the initial portion of the ascent trajectorydeveloped above. Comparisons between the resultant best estimate trajectoryand the available tracking data show consistency and good agreement.

4-1


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.

Table 4-l. Tracking Data Sumnary

DATA SOURCE, TYPEBERMUDA, C-BANDBERMUDA, C-BANDBERMUDA, S-BANDBERMUDA, S-BANDCAPE KENNEDY, C-BANDHAWAII, C-BANDMERRITT ISLAND, C-BANDPATRICK, C-8ANDTANANARIVE, C-BANDTANANARIVE, C-BANDWALLOPS ISLAND, C-BAND

RAN&E TIME INTERVALPHASE (SEC)ASCENT 290 - 620ORBITAL 577 - 709ASCENT 413 - 620ORBITAL 597 - 747ASCENT 1 - 418ORBITAL 15,997 - 16,195ASCENT 6 - 524ASCENT 25 - 514ORBITAL 7807 - 8167ORBITAL . 13,333 - 13,693

ASCENT/ORBITAL 210 - 620

Telemetered guidance data were used as a node1 for obtaining propervelocity and acceleration profiles through the transient areas of Mach 1,maxfmum dynamic pressure, S-IB thrust decay and S-IVB thrust decay.Actual ano nominal altitude, cross range, and surface range for the boostphase are presented in Figure 4-1. Figure 4-2 presents similar cwpari-sons of space fCxed velocity and flight path angle. Comparisons ofactual and nominal non-gravitational accelerations are displayed fnFigure 4-3. Inspection shows the actuals were very close to the naninalvalues.Trajectory parameters at significant events are presented in Table 4-2.Table 4-3 presents the trajectory conditions at engine cutoffs. Table4-4 presents significant parameters at the S-IB/S-IVB and S-IVB/CSHseparation eventsThe S-IB stage OECO was a result of LOX depletion. The S-IVB cutoffsignal was issued by the guidance computer when end conditions weresatisfied.


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1600

Jz 1200

400

0

P--L

-160; 100 200 300 400 500 600RANGE TIME, SECONDS

Figure 4-1. Ascent Trajectory Position Comparison

---


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8000

7000

6000rr.2 .zg 5000id>E:; 4000s2Y,

3000

2006

1000

0

- FLIGHT PXY .MGLEI I /

ACTUAL -NOMNAL--

500 6RANGE TINE, SECONDS

Figure 4-2. Ascent Trajectory Space-Fixed Velocity and Flight PathAngle Congari son


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5or----7-----

--

-

---

LEGEND:ACTUAL -NOMINAL - -

-v S-IB IECOv S-IB OECO -+--v EMR SHIFTv S-IVB GCS

0 400 500 6RANGE TIME, SECONDS

Figure 4-3. Ascent Trajectory Acceleration Comparison


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Table 4-2. Comparison of Significant Trajectory Events

__--EVENTFirst Motion

Mach 1

Haxbnun Dynamic Pressure

l Maximum Non-GravitatfonalAcceleration: S-16

S-IV6

l MaximumEarth-FixedVelocity: SIB

S-IVB

Warest Time Points Available

PARAMETERRange Time, setNon-GravitationalAcceleration, m/s2Range Time, setAltitude, km

Range TM. setDynamic Pressure,N/cdAltltude. km

ACTW NOMINAL0.271 0.271

ACT-NON7.OW12.347 12.218 0.12959.500 59.372 0.1287.48 7.47 0.01

69.500 74.358 -4.8583.258 3.337 -0.07910.72 12.59 -1.87

Range Time, set 137.814 137.975 -0.161Acceleration, m/s2 42.198 42.642 -0.444Range Time, set 577.176 579.351 -2.175Acceleration, m/s2 28.742 28.588 0.154Range Tlme,secVelocity. m/sRange T!me, setVelocity, m/s

141.500 141.271 0.229D37.59 037.27 0.32581.000 581.271 -0.271534.33 533.52 0.81

Mach nuber and dynamic pressure history cmparisons are shown in Figure4-4. These parameters were calculated using measured meteorologicaldata to an altitude of 59 km. Above this altitude the U.S. StandardReference Atmosphere was used. ,A theoretical free-flight trajectory was canputed for the spent S-18stage, ;rsing initial conditions from the actual trajectory at S-IB/S-IVBseparation signal. Three trajectories were integrated from that pointto impact using nominal retro-motor performance and outboard engine decaydata. The three trajectories incorporate three different drag conditions

4-6


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Table 4-3. Comparison of Cutoff Events

PARJXTER S-16 IECO S-:8 OECO I S-;YB KS

Range T ime ;sec)Altitude (cm)Space-Fixed Velocity [m :s)Flight Path Angle (de9)

I Madin Angle (deq)Surface Range (km ;Cross Range ikm)Cross Range Velocity (m/s ) ( -16.30

Table 4-4. Comparison of Separation Events

I S-IB/S-IVB s- IVB/CSMPARAMETER ACTUAL NOMINAL 1 ACT-NOM , ACTUAL NOMINAL ACT-NO!'Range Time (set) 142.54 142.28 / 0.26kltitude (km) i

j 1080.00 1059.55 20.4558.54 1 58.54 0.00 j 169.62 168.74 ,

7825.58 Ij 0.88/Space-Fixed Velocity (m/s) 2345.79 1 2344.93 0.86 7826.21 -0.63

Flight Path Angle (deg) 23.449 ! 23.576 -0.127 0.201' 0.188 0.013'eading Angle (deg)

I59.918 59.983 1 -0.065 87.334 85.614 1.720

Geodetic Latitude (deg. North 28.984 1 28.980 , 0.004 50.165 50.067 0.098Longitude (deg. West) 80.355 1 80.060 ) -0.005 21.767, 23.936 2.169Surface Range (km) I67-8g i 67.27 i

!O-62 _ _ _ _ _ _Cross Range (km) 0.60 0.75 -0.15 - - -- --Cross Range Velocity (m/s) -19.12 -17.07 -2.S 1 -- -- --


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4.0

3.5

3.0

1.0

0.5

0

-MACH NUMBERMACH NUMBER

0 40 80 120 160RANGE TIME, SECONDS

Figure 4-4. Ascent Trajectory Dynamic Pressure and Mach Number Comparison


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for 1) stabilized at zero angle of attack (nose forward), 2) tumblingstage, and 3) stabilized at 90 degree angle of attack (broadside).Tables 4-5 and 4-6 summarize the results of these simulations and presentthe impact envelope. Tracking data were not available, but previousflight data indicates the tumbling drag trajectory to be a close approxi-mation to actual flight conditions. The calculated impact for this casewas 31.19 degrees north latitude, 76.46 degrees west longitude.4.2.2 Orbital PhaseOrbital tracking was conducted by the National Aeronautics and SpaceAdministration (NASA) Space Tracking and Data Network. One C-Band(Bermuda) and one S-Band station (Bermuda) were available for trackingcoverage during the first revolution. Tananarive provided second andthird revolution coverage while Hawaii afforded additional third revolu-tion coverage. Some high speed tracking data beyond insertion wereavailable from Wallops Island. These data were edited to provide addi-tional orbital tracking information. The trajectory parameters at orbitalinsertion were established by adjusting the preliminary estimate of theinsertion conditions to fit the orbital tracking data. A comparison ofthe actual and nominal parking orbit insertion parameters are delineatedin Table 4-7. Figure 4-5 presents the SL-4 ground track from lift-offthrough CSM separation.


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Table 4-5. Comparison of S-IS Spent Stage Impact

PARAMETER ACTUAL NOMINALRange Time (set) 534.26 534.78Surface Range (km) 492.58 494.65Cross Range (km) -0.51 1.53Geodetic Latltude (deg. North) 31.193 31.187Longltude (deg. West) 76.455 76.425

NOTE: Data reflects simulation of tumbling stage

ACT-NOM-0.52-2,07-2.04

0.0060.030

Table 4-6. S-IB Spent Stage Impact Envelope 7DRAG SIMULATIONPARAMETER NOSE FORWARD TUMBLING BROADSIDE,

Range Tlme (set) 472.67 534.26 575.39Surface Range (km) 505.91 492.58 483.07Cross Range (km) -0.43 -D.51 -0.55Geodetic Latftude (deg, North) 31.26 31.19 31.14Longltude (deg. West) 76.34 76.46 76.54


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Table 4-7. Comparison of Orbit Insertion Conditions

r ----- -.._--._. .--

PARAMETERRange Time (set)Altitude (km)Space-Fixed Velocity (m/s)Flight Path Angle (deg)Heading Angle (deg)Cross Range (km)Cross Range Velocity (m/s)Inclination (deg)Descending Node (deg)

(EccentricityApogee AltitudePerigee AltitudePeriod (min)

km)(km)

I eodetic Latitude (deg. North)Longitude (deg. West)

--__-. -.----ACTUAL NOMINAL587.18 589.35158.33 158.22

7836.82 7836.090.006 0.003

54.853 54.935-145.68 -146.92

-1199.93 -1196.7450.048 50.033

156.979 156.9660.0059 0.0057

227.08 224.24150.10 149.96

R8.26 88.2328.432 38.48764.841 64.744

4-11

ACT-NM!-2.17

0.110.730.003

-0.0821.24

-3.190.0150.0130.00022.840.140.03

-0.0550.097-


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D --


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SECTION 5S-IVB/IU DEORBIT TRAJECTORY

5.1 SUMARYAll aspects of the S-IVBJIU deorbit were accomplished successfully. Thepropellant dump was performed as planned with impact occurring in theprimary disposal area. Honeysuckle confirmed that the vehicle wassafed following the propellant dump. Although breakup occurred afterloss of signal at Kwajalein, Department of Defense (DOD) sources con-firmed the deorbit.5.2 DEORBIT MANEUVERSTimebase 5 (start of S-IVB/IU deorbit events) was initiated at 18.637.7seconds (301 minutes past Timebase 4) with the vehicle already in theretrograc- attitude. A deorbit LOX dump of 475 seconds duration andan LH2 dump of 86 seconds were implemented. Remaining pneumatic pressurewas sufficient for vehicle safing.The retrograde velocity incrementis achieved from the LOX and LH2 tankdumps are presented in Table 5-1, and compared with the real time predic-tions. The actual total dump velocity was slightly less than nominal,but well within the -3 sigma prediction.

Table 5-l. S-IVB-208 Propellant Dump Deorbit Velocity

REAL-TIME IACTUAL PREDICTED ACT-RTLOX Dump AV (m/s) 17.93 10.17 -1.24LH2 Dump Av (m/s) 2.61 2.70 -0.09Total Dump AV (m/s) 20.54 I 21.87 -1.33

(LOX Dump Duration = 475 SecondsLH2 Dump Duration = 86 Seconds I


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5.3 DEORBIT TRAJECTORY EVALUATIONA timebase 5 state vector, obtained from the orbit trajectory reconstruc-tion (actua;) discussed in Section 4, was utilized to initialize the re-entry trajectory which terminates with breakup. The LOX and LH ? dumpdata used in setenining this trajectory were taken from the te emeteredaccelerometer data. The altitude profile developed differs only slightlyfrom the real time prediction, as shown in Figure 5-l. The difference inaltitude is attributable to the slightly lower than nominal (real timepredictionj *etragrade velocities mentioned above.Honeysuckle verified that the vehicle was safed following the propellantdump. Kwajalein radar tracked the S-IVB/IU, but did not establish break-up since it occurred after loss of signal. Other DOD sources did confirmdeorbit. A breakup altitude of 81.7 km was assumed for the concludingpart of the reentry simulation. This altitude was selected c,',nce it wasobserved by Kwajalein as the actual breakup altitude during the SA-207flight.5.4 IMPACTThe impact area of the S-IVB/IU is illustrated in Figure 5-2, which alsoshows the ground track past Kwajalein. The limits of the impact areawere defined by simulation, assuming a range of ballistic coefficientsfrom 47 to 650 kg/m2. Table 5-2 presents the short range, nominal,and long range impact point coordinates as they occurred in the plane ofthe trajectory. These data show that the impact area was approximately925 km (500 n.mi.) in length and well within the planned disposal area=

Table 5-2. S-IVB-208 Impact Dispersion Limits1

SHORT LONGRANGE NOMINAL RANGERange Time (set) 21,836 21,732 21,672Latitude (deg), N 24.5 26.5 30.1

1 Longitude (deg), W 172.3 170.3 166.2

5-2


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axduq 02 dwna )(3eq punoq ~I/~AI-S 1-5 am6kj

533u930 '3afu19t407

SOE

soz

308 II

39NV?J INOHS. *NOEI- -~ -- ~-. IV3dV 13VdWIi ^~. _- .._ -_--._ ._-- .___ _~_ -J


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SECTION 6S-IB PROPULSION

6.1 SUlWARYThe S-IB stage propulsion system performance was satisfactory throughoutflight. Stage longitudinal site thrust averaged 0.13 percent lower thanpredicted. Stage LOX, fuel, and total flowrates averaged 0.10 percent,0.18 percent, and 0.13 percent lower than predicted. respectively.Stage mixture ratio averaged 0.08 percent higher than predicted. Stagespecific impulse was within 0.04 percent of predicted. Inboard EngineCutoff (IECO) indicated by measurement VKOOOl-012 occurred at 137.82seconds (0.16 seconds earlier than predicted). Outboard Engine Cutoff(OECO) indicated by measurement VK0003-012 occurred 3.47 seconds afterIECO at 141.29 seconds (0.31 seconds later than predicted). OECO wasinitiated by engine no. 1 thrust OK pressure switch deactuation (LOXstarvation). At OECO, the LOX residual was 2925 lbm compared to thepredicted 3287 lbm, and the fuel residual was 6878 lbm compared to thepredicted 5989 lbm. The stage hydraulic system performed satisfactorily.6.2 S-IB IGNITION TRANSIENT PERFORMANCEAll eight B-1 engines ignited satisfactorily. The automatic ignitionsequence, which schedules the engines to start in pairs with a 100-millisecond de1 ay between each pair, began with the time for ignitioncorunand at -3.050 seconds range tillle. The start sequence that occurredwas close to optimum. The maximum spread in the start time, defined bythe intersection of the extrapnlated maximum slope of chamber pressureor thrust buildup with the zero line (Pc prime times) of en ines withina pair was 25 milliseconds and was between engines 2 and 4 9 third pair ofengines). The smallest interval in the planned 100-millisecond sequencebetween pairs was 75 milliseconds and was between the third pair's laterengine and the fourth pair's earlier engine (specifically, between engines2 and 3).Table 6-l compares predicted and actual start event times. The individualengine thrust buildup curves are shown in Figure 6-1. The thrust valuesshown are the engine chamber thrusts and do not account for cant anglesor turbine exhaust thrust.

6-l


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Table 6-l. S-IB Engine Start Characteristics

(1) Values referenced to Termina l Countdan Sequencer (TCS) event"Time for Ignition Comnand"(2) Values presented are mean values S-18-6 through S-18-12 static test.Technical Bulletin - FLVE-65-148. Revision. 3. Swbple means andstandard deviations wre: Time to thrust chrllber ignition 583.7msec mnd 18.4 msec ; time tp PC prime B74.6 mse c and 22.6 IRSU.

6.3 S-IS MAINSTAGE PERFORMANCES-IB mainstage flight performance, Figure 6-2, was satisfactory. Stagelongitudinal site thrust averaged 2330 pounds (0.13 percent) lower thanpredicted. The stage specific impulse d2-ing flight was within 0.04 per-cent of predicted. Stage mixture ratio averaged 0.0019 (0.08 percent)higher than predicted.lower than predicted. Total flowrate averaged 8.0 lbm/sec (0.13 percent)Stage LOX and fuel flawrate, Figures 6-3 and 6-4,averaged 4.5 lbm/sec (0.10 percent) and 3.5 lbm/sec (0.18 percent) lowerthan predicted, respectively. These average deviations were taken be-tween first motion and IECO.The fuel temperature was 5.4OF lower than predicted which normally wouldhave significantly decreased thrust and total flowrates; however, *Lheeffects of the more dense fuel were almost entirely compensated for by aslightly higher LOX tank pressure and a lower LOX temperature than pre-dicted.Early IECO (0.16 seconds earlier than predicted) and late OECO (0.31seconds later than predicted) were primarily the result of a greaterthan predicted level difference between the outboard LOX tank number 2(O-2). which signalled level sensor actuation and the other fourtanks, particularly, the center tank. The lower than predicted level inthe O-2 tank caused less LOX to be consumed by the inboard engines before


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I-i-E


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A----T-----c--e. . - ! 1 ,

6-4


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2ooo~ .- ACUAL I--- PREDICTED I

loooc I vm ,-0 20 40 loo 120 140

Figure 6-3. S-IB LOX Flwrate

- ACTUAL---PREDICTED

.2500

500

RAKE TIM E. SEWDSFigure 6-4. S-IB Fuel Flow-ate

6-5


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, 5.

LOX depletion occurred. The predicted performance was determined beforeany stages with 205Klbf thrust engines had flown. Since the flight ofS-16-6, it was expected that the fuel and LOX tank pressures would behigher, the fuel temperature lower, and the LOX level in O-2 lower thanpredicted for S-IB-7 and S-IB-8. The combined effects of these smalldeviations do not significantly affect stage performance and predictionupdates were not considered necessary.Table 6-2 compares individual S-IB engine propulsion performance to pre-dicted values when reduced to standard sea level conditions.The predicted sea level values for the S-IB-8 engines were calculated ina similar manner to the sea level values for the S-IB-7 engine pre-diction data. The predicted thrusts, turbine speeds and flowrate sealevel data were derived by increasing the engine manufacturer's accept-ance test data to be consistant with the trends noted durl>g the flightsof S-IB-1 through S-IB-5 with 200Klbf thrust engines. The 8-engine averagesea level thrcr;t, LOX flowrate, and specific impulse were within 0.1percent of those predicted. The average sea level fuel flowrate andmixture ratio were within 0.26 percent of those predicted.6.4 S-IB SHUTflOWN TRANSIENT PERFORMANCEThe cutoff sequence began at 134.88 seconds with the actuation of the 1~level sensor in LOX tank O-2 as indicated by measurement VKOOO15-002. Itshould be noted that this measurement has an 83 millisecond sampling rate,therefore, this event could be as much as 0.083 seconds earlier thanindicated by this measurement. IECO was initiated 2.94 seconds later bythe Launch Vehicle Digital Computer (LVDC) at 137.82 seconds as indicatedby measurement VKOOOl-012. Thrust of each inboard engine was normal.The total IECO impulse was 238,258 lbf-sec. Inboard engine total thrustdecay is shown in Figure 6-5.LOX starvation occurred in the four outboard engines as planned. Out-board engine total thrust decay is shown in Figure 6-6. The total OECOimpulse was 181,550 lbf-sec. Each engine has three thrust OK pressureswitches, and as engine performance decays during LOX starvation, thefirst outboard engine to lose thrust OK signal fran two-out-of-threeswitches, will simultaneously cut off all outboard engines. Engine 1initiated OECO which occurred at 141.29 seconds range time as indicatedby measurement VKOOO3-012.6.5 S-IB STAGE PROPELLANTMANAGEMENTThe effectiveness of propellant management may be aPasured by the ratioof propellant consumed to propellant loaded which is an indication of thecapability of predicting mixture ratio and of the propellant loading systemto load the proper propellant msses. The predicted and actual (recon-structed) percentages of loaded propellants utilized during the flightare shown in Table 6-3.


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Table 6-2. S-IB Indivldual Engine Propulsion Performance*

a WI, 56266,662 206, SDS06, SDS J. M4. M4 262.H62.2R 262.6462.64 v. 137.137 545.35S.35 550.4450.42 u. 9nu. 9nu 242.2242.22 243.11043.110 u..6S252 2.2515.2515 2.2577.2577 0. 27S. 37S3 205,16705,167 204,33604,326 -0.4100.410 262.7762.77 262.6762.67 -0.03A0.03A 539.9539.95 53n. 173% 17 -u.311u.311 240.9640.95 239. m039. m0 -0. 5130. 513 2.2405.2405 2.2452.2452 u.210.2104 264.16764.167 2s4,662s4,662 0. u37. u37 262.1362.13 2w.19(i& 19 U.923. 923 Sm.67m. 67 SJO. 14JO. 14 II. w:I. w: 241. 5.441. 5.4 241.1241.12 -IL 149IL 149 2. 233!I. 233!I 2.2392.2392 1l.237.23;5 299,73299,732 296,96696,966 -0.6460.646 264.0864.09 263.6563. d5 -0.u470. u47 517.7417.74 S43.0943.99 -U. iU3U. iU3 24iS.664L 66 24% 534% 53 -0. 9780. 978 2.2572.2572 2.2612.2612 II.I. 177776 262,10662,lOL 20% 7470% 747 0.316.316 262.7062.70 262.8662.86 0.061.061 S36.5736.57 53% 353% 35 0.332.332 236.S736. S7 236.7636.76 u. 090. 090 2.26132.26R2 2.2739.2739 0.251.251.7 208,60608,696 204,15004,150 -0. n530. Rs3 263.3363.33 263.u963.u9 -0.0910.091 :AI. 90l. 90 538.1538.15 -0.7070.707 239.9539.95 237. no37. RO -0. 9960. 996 A2544.2544 2.2630.1630 0.196.1966 205,66105,661 204,99404,994 -0.2950.295 263.7663.76 263.7363.73 -0.0190.019 539.6939.69 538.7638.76 -0.2U90.2U9 239.5539.55 236.5236.52 -0.4300.430 2.2533.2533 2.2517.2517 U.Zli.?li

AVOVO 265,61165,611 206,61206,612 -0.0960.096 262.9762.97 262.9862.98 0.006.006 542.0442.04 541.6641.66 -0.0320.032 240.6040.60 239.9939.99 -0.2570.257 2.2529.2529 2.2S40.2S40 0.224.224 14I *Standard'Sea Level Conditions at 30 SetStandard'Sea Level Conditions at 30 Set II LOX density 70.79 lbm/ft3Fuel density 50.45 lbm/ft3 Fuel pump Inlet pressure 57 pslaAWent Pressure 14.696 psia LOX pump inlet pressure 65 pslaFuel temperature 60F I


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N SOL 'ISIIWU 39VlS

0 ul a0 h 40 u) t c3 N c 0c441 $01 1snw 39vlS


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1 1 I I I

v,I3 I I I I I I

Ii I I I I I I Ie

0 m a0 h rg In e (3 cv c fC441 SOL 1smtu 39VlS


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Table 6-3. S-IB Stage Propellant UsagePROPELLANT PREDICTED (L) ACTUAL (X)

Total 99.20 99.12Fuel 98.34 98.02LOX 99.58 39.61

The center LOX tank sump orifice was lg.0 (+D.OOS) inches in diameter,and a liquid level height differential of aEproximately 3.0 inches be-tween the center and outboard LOX tanks was predicted at IECO (centertank level higher). The LOX and fuel level cutoff sensor heights andflight sequence settirigs were determined for a 3.00-second tilne intervalbetween cutoff sensor actuation and IECO. The planned time interval be-tween IECO and OECOwas 3.00-seconds. The planned mode of OECO was byLOX starvation. OECOwas to be initiated by the deactuation of two ofthe three thrust OK pressure switches on any outboard engine as a re-sult of LOX starvation and the subsequent thrust decay. It was assumedthat approximately 271 gallons of LOX in the outboard suction lines wereusable. The backup timer (flight sequencer) was set to initiate OECD13.00 seconds after level sensor actuation.To prevent fuel starvation, fuel depletion cutoff sensors were locatedin the F2 and F4 container SUIIPS. The fuel bias for S-16-8 was 1550 lbm.This fuel mass, included in the predicted residual, was available forconsumption to minimize propellant residual due to off-nominal conditionsand is not expected to be used during a nominal flight.The cutoff Lequence on S-IB-8 was initiated by a signal from the cutofflevel sensor in tank O-2 at 134.88 seconds. The IECD signal was received2.94 seconds later at 137.82 seconds. OECO occurred 3.47 seconds afterIECO at 141.29 seconds. OECOwas initiated by engine no. 1 thrust OKpressure switch deactuation. Fuel depletion probes in the fuel tank supswere not actuated prior to retm'ior ignition.Based on discrete probe data, liquid levels in the fuel tanks were nearlyequal and approxilllately 24.7 inches above theoretical tank bottom at IECD.This level represents a loss of 11,580 lbnr of fuel onboard. At that tim,11,033 lbm of LOX Mined onboard. Corresponding liquid height in thecenter tank was approximately 14.7 inches and average height in the out:board tanks was approximately 10.3 inches above theoretical tank bottan.Propellants remaining above the main valves after outboard engine decaywere 2,390 ltxs of LOX and 5,549 l&I of fuel. Predicted values for these


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quantities were 2,642 lbm of LOX and 4,628 lbm of fuel.Cutoff level sensor signal times and setting heights from theoreticaltank bottom are shown in Table 6-4.

Table 6-4. Cutoff Level Sensor Actuation Characteristics

TANKI

HEIGHTI

ACTUATICN TIME(inches) (seconds)i: 27.57.5 135.0534.WF2 31.4 136.36F4 31.4 136.44I * 83 millisecond sampling rate I

Total LOX and fuel masses above the main propellant valves beginning atignition corrnrand are shown in Figure 6-7 and 6-8. A s-t-y of the pro-pellants remaining at major event times is presented in Table 6-5.

Table 6-5. S-18 Stage Propellant Mass History

EVENT

Ignition CammdIU UabilicalDisconnectIECDDECO

PREDICTED (lbm) RECONSTRUCTED (lbm)FUEL Lox 1 TOTAL FUEL 1 LOX 1 iDTALi I279.594 632.015 1 911.609 28D.540 1 632,415 912.955

275.625 620,632 1 096.257 276.709 1 619.910 896.61910.247 10.437 i

i2Dmm4 1 11.580 1 11,033

I22,613

I5,989 3.287 , 3.276 f 6,878 ! 2,925 1 3.803Separation Comand 4.900 2.725 i 7,5g2 i 5.823 2,473 j 8,296,. 1

IZero Thrust 4,623 2,642 7.270 5.549 i 2,390 7,939


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I I I III I

1_ _-..700

300

250

300 I I I \I I I I II I 1 I I I

%I 0 20 40 60 60 100 120 140 160RAN6E TIME, SECONDS RANtiE TIME. SECONDS

150

la0

,w

100

0-20 0 20 40 60 60 100 120 140 160

100

2CIs! I9?dz

' 50

-0

Figure 6-7. S-IB LOX Mass Above Main LOX Valve Figure 6-8. S-IB Fuel Mass Above Main Fuel Valve


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6.6 S-18 PRESSURIZATION SYSTEM6.6.1 Fuel Pressurization SystemThe fuel tank pressurization system performed satisfactorily during theentire flight and no anomalies were observed. With the exception of achange in the vent valve relief pressure setting and minor changes inthe vent valve sensing lines, the pressurization system was the same ason S-IB-7 and included the two 19.28 ft3 high-pressure helium spheres,light weight tanks and fuel vent valves. Because of the accidentaldamage to the upper bulkheads on fuel tanks F3 and F4 during prelaunchactivities (see Section 3.4.1), the vent valve relief pressure was loweredfrom the normal 21.0/21.5 psig to 19-O/19.1 psig to maintain adequatestructural margin. In addition, expansion loops were added to the ventvalve sensing lines on the upper bulkheads to relieve the strain on thesensing system caused by the increased bulkhead deflection. To reducethe peak pressure during tank prepressurization, a pressure switch wasselected which showed the lowest actuation pressure during pressureswitch calibration tests. The switch installed on S-IB-8 actuated at31.5 psia and deactuated at 30.3 psia during calibration.Helium flow into the fuel tank ullage is metered by a sonic nozzle be-tween the high-pressure spheres and the tanks. The orifice diameter ofthe sonic nozzle was 0.220/0.221 inches. Sufficient pressure must beprovided by this system to meet Fuel Net Positive Suction Head (NPSH)requirements at the end of flight and maintain structural integritythroughout flight. Both requirements were met. The pressures that de-fine the operating band are 10 psig minimum for structural integrity andthe minimum vent valve relief pressure of lg.0 psig. Fuel ullage pressureremained within these limits.A comparison of measured ullage pressure and predicted ullage pressureis presented in Figure 6-9. Measured ullage pressure compared favorabiywith predicted ullage pressure during the flight and at no time exceededa difference of 1.0 psia from the predicted value.The Digital Events Evaluator showed that fuel vent valves 1 and 2 closedat the beginning of the pressurization sequence and remained closed untilliftoff. No vent valve position instrumentation is available duringflight but inspection of the fuel tank ullage pressure history revealsno reason to suspect that the vents opened during flight.Tank pressurization began at T-159.86 seconds. The 1527-gallon (3.61 per-cent) ullage volume was pressurized to 32.2 psia in 2.43 seconds. Due tothe ullage cooling, the pressurization valves opened again at T-135.73seconds for a period of 0.23 seconds to repressurize the fuel tank ullage.This is about 15 seconds earlier than in previous flights and results fromthe increased ullage pressure decay rate due to fuel vent and relief valve


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pilot valve leakage, and from the tighter operating band on the pressureswitch.S-IS-8 was the first stage to have noticeable pilot valve leakage be-cause the pilot valve assembly is normally adjusted to provide reliefactions at 21.0/21.5 psig and poppet reseating at 19.0 psig. The valvesused on S-IB-8 differed from the normally qualified valves in that therelief setting was reduced to 19.0/19.1 psig to accommodate a loweredproof pressure for tne tanks. The effect of the reduction of reliefpressure was also to reduce reseat pressure to approximately 17.0 psig.Pilot valve leakage was then approximately 4000 SCIM per valve at atank ullage pressure of 18.0 psig, whereas there was zero leakage at18.0 psig for valves qualified to relieve at 21.0/21.5 psig.The Digital Events Evaluator shows that the pressurizing valves openedthree times to repressurize the fuel tank. Two of these repressurizationcycles occurred during the engine start sequence.Telemetry data show helium sphere pressure to be 2903 psia at liftoffwhich is slightly higher than it was on S-IB-7. The sphere pressure isshown in Figure 6-10.Because the fuel temperature and ullage pressure were different in eachof the tanks, the liquid levels were different. The maximum differencebetween tanks Fl and F3, determined from recorded discrete probe data,was 10.2 inches at 8.2 seconds. The levels converged to a difference of0.6 inches at approximately 138.0 seconds.6.6.2 LOX Pressurization SystemThe LOX tank pressurization system performed satisfactorily during theentire flight.Following the LOX bubbling test at T-4 hours, 8 minutes; the LOX ventswere closed on three occasions prior to prepressurization as a personnelsafety procedure against LOX spillage through the vents. The vents wereclosed at T-4 hours, 2 minutes; T-2 hours, 40 minutes; and T-55 minutesfor durations of 129 seconds, 135 seconds, and 150 seconds, respective'y.Prepressurization began with the hellum pressurizing valve opening atT-102.893 seconds as shown in Figure 6-11, and was accomplished in 55.21seconds, compared to 73.3 seconds for S-IB-7. The faster pressurizingrate occurred because of increasing the ground pressurizing orifice dia-meter from 0.100 to 0.114 inch.With the additional 18 seconds for ullage decay, the pressure switch cycled6 times prior to ignition, which is 3 more than S-IB-7. The switch actu-ated at approximately 57.7 psia and deactuated at 56.2 psia, which iswithin the switch limits. The bypass orifice flow was initiated at T-2.38?


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- 1500

RANGE TIME, SECONDSFigure 6-10. S-IB Fuel Tank Helium Pressurization Sphere Pressure

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seconds, while the pressurizing valve was open during the final cycle.The reconstructed LOX ullage volume prior to vent closure of 994 gallons(1.48 percent) was the same as that on S-IB-7.The ullage pressure during flight is compared with the predicted pressurein Figure 6-12. The minimum pressure of 47.2 psia occurred during theengine start transient and the maximum pressure of 52.7 psia occurredat 33 seconds. The GOX Flow Control Valve (GFCV) started to close atignition, and after the normal hesitations during the start transient,reached the fully closed position at 20 seconds and remained closed until50 seconds as shown in Figure 6-13. The predicted GFCV position is notshown because the valve was originally installed on S-IB-6 and removedafter the stage test.The GFCV moved of f the minimum position at 50 seconds, which was 22seconds earlier than S-IB-7. The earlier opening time is attributedto a lower ullage pressure than on S-IB-7, because GFCV opened at anullage pressure of approximately 52 psia on both flights. The GFCVcontinued to open gradually for the remainder of the flight to 21 percentopen at IECO, while the ullage pressure decayed to 49.5 psia.6.7 S-IB PNEUMATIC CONTROL PRESSURE SYSTEMThe S-IB pneumatic control pressure system supplied GN2 at a regulatedpressure of 769 to 686 psia to pressurize the H-l engine turbopuAp gear-boxes and to purge the LOX and lube seal cavities and the two radiationcalorimeters. This regulated pressure was also used to close the LOXand fuel prevalves at IECO and OECO. The actual sphere pressure historyrecorded by measurement XWO40-009 mined within the acceptable bandas shown in Figure 6-14.6.8 S-IB HYDRAULIC SYSTEMThe system hydraulic pressures were satisfactory during flight and weresimilar to those of the SA-207 flight. At zero seconds the systm pres-sures ranged from 3190 to 3250 psig. The pressure decreased approximately50 psi on each engine during flight. This nonaal pressure decrease wasdue to the main pump temperature increase during the flight.Reservoir oil levels were also similar to those of the SA-207 flight.There was a rise of approximately 2 percent in each level during flightindicating about 7OC rise in each h draulic system's average oil teeqera-ture (not reservoir oil temperature,. 3The reservoir oil temperatures were satisfactory during flight. Thetemperature

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Saturn 1B Launch Vehicle Flight Evaluation Report SA-208 Skylab-4

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