MSFC Skylab Airlock Module, Volume 2

8/8/2019 MSFC Skylab Airlock Module, Volume 2

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MSFCSKYLABAIRLOCKMODULE

Vol, IiSkylab Program OfficeNASA _% ,_!,..?_ _)

GeorgeC. N_sball SpaceHight CenterN_fsbM! X_ceHight Ce_te_,Al_Mma(HAS A-TH-I-69810- Vol-21 _SFC SKYLAB NT_-25338AIRLOCK HODULE, VOLUSE 2 Final RepoEt(N_S&) 652 p HC $11.00 CSC_ 22B OnclasG_/_I _0152


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AIRL'OCK MODULE FINAL TECHNICAL REPORT MDCE0899 VOLUMEIITABLEOF CONTENTS

VOLUMEISECTIONI INTRODUCTION 1-I

l.l PURPOSEAND SCOPE I-I1.2 SUMMARY I-2-1.2.1 AirlockFeatures I-23.2.2 AirlockModuleWeightand Dimensions I-91.2.3 FASWeightand Dimensions 1-91.2.4 DA Weightand Dimensions 1-I01.2.5 PayloadShroud(PS) l-lO1.2.6 Environmental/ThermalontrolSystems(ECS/TCS) 1-111.2.7 ElectricalPowerSystem (EPS) 1-121.2.8 SequentialSystem 1-121.2.9 Instrumentationystem 1-121.2.10 Communicationsystem 1-131.2.11 Cautionand WarningSystem(C&W) 1-141.2.12 Crew Systems 1-151.2.13 Trainers I-_6l.2.14 Experiments 1-16I 2.15 GroundSupportEquipment(GSE) 1-17l 2.16 Reliabilityand Safety 1-17l 2.17 Testing 1-181 2.18 MissionOperationsSupport 1-19Jl 2.19 New Technology 1-20l 2.20 Conclusions ' 1-21

SECTION2 SYSTEMDESIGNAND PERFORMANCE 2.1-12.l GENERAL 2.l-l2.I.l ProgramInception 2.l-I2.1.2 SSESM 2.l-l2.1.3 Wet WorkshopEvolution 2.1-32.1.4 Wet WorkshopConfiguration 2.1-62.I.5 Dry _orkshopConfiguration 2.1-62.2 STRUCIURESAND MECHANICALSYSTEMS 2.2--I2.2.1 DesignRequirements 2.2-12.2.2 SystemsDescription 2.2-a

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AIRI.OCK MODULE FINAL TECHNICAl- REPORT MDCEOeggVOLUMEITABLEOFCONTENTSOLUME CONTINUED

2.2.3 SystemVerification ; 2.2-222.2.4 MissionResults ' 2.2-30:;:.?.5 Conclu_,_onsnd Recommendations 2.2-312.3 MASSPROPERTIES 2.3-I2.3.1 Airloc_WeightMonitoringPlan 2.3-12.3.2 ActualWeightProgram 2.3-32.3.3 Launch_eight 2.3-62.4 THERMALCONTROLSYSTEM 2.4-I2.4.3 Design:iRequiements 2.4-I2.4.2 IntegratedThermalAnalysls 2.4-52.4.3 Syste_Description 2.4-132.4.4 Teething 2.4-602.4.5 Mission Performnce 2.4-982.4.6 DevelopmentProblems 2.4-1212.4.7 Conclusions and Recommendations _ 2.4-1232.5 ENVIRONMENTALCONTROLYSTEM : 2.5-I

--- 2.5.1 DesignRequirements , _ 2.5-I-, 2.5.2 SystemDescription 2.5-9

2.5.3 Testing 2.5-562.5.4 MissionResults 2.5-882.5.5 DevelopmentProblems 2.5-I192.5.6 Conclusions and Recommendations 2,5-1222.6 EVA/IVASUIT SYSTEM 2.6-12.6,1 Design Requirements 2.6-I2.6.2 System Description _ ,2.6-42.6.3 Testing _ 2.6-28.6.4 MissionPerformance 2.6-462.6.5 DevelopmentProblems 2.6-522.6.6 Conclusionsand Reconm_nclations 2.6-542.7 ELECTRICALPOWERYSTEM 2.7-12,';7.1 :Design Requirements 2.7-12.7.2 System Description 2,7-32.7.3 Testing 2.7-442,7,4 Mission Results 2.7-842.7.5 Conclusions and Recommendations 2.7o143

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i AmLOCK MODULE FINAL TECHNICAL R_PORT _DC EO8990VOLUME _|_ TABLE OF CONTENTS VOLL_E I AN_ I I_ 2.8 SEQUENTIAL SYSTEM Z.8-12.8.1 Payload Shroud Jettison Subsystem 2.8-5I

i 2.8.2 ATM Deploy_e.ntSubsystem 2.8-19I2.8.3 Discone Antenna Deployment Subsystem 2.8-282.8.4 Power Control Subsystem 2.8-322.8.5 Radiator Shield Jettison/RefrigerationSubsystem

Activation 2.8-362.8.6 OWS Venting Subsystem 2.8-402.8.7 OWS Meteoroid Shield Deployment Subsystem 2.8-472.8.8 OWS SAS Deplo_nnentSubsystem 2.8-492.8.9 ATM SAS Deployment/CanisterRelease Subsystem 2.8-532.8.10 ATM Activation Subsystem 2.8-572.8.11 MDA Venting Subsystem 2.8-602.9 INSTRUMENTATIONSYSTEM 2.9-I

' 2.9.1 Design Requirements 2.9-I2.9.2 System Description 2.9-32.9.3 Testing 2.9-262.9.4 Mission Results 2.9-352.9.5 Conc|usionsand Recommendatioq_ 2.9-41I

' VOLUME II2.10 COMMUNICATIONS SYSTEM 2.10-12.10.I Audio Subsystem 2.10-62.10.2 Data Transmission and Antenna Subsystem 2.10-23

" 2.10.3 Digital Command Teleprinter and Time ReferenceSubsystem 2,|U-412.10.4 Rendezvous and Docking Subsystem 2.10-672.11 CAUTION AND WARNING SYSTEM 2.ll-I2.11.I Design Requirements _ 2.11-2

" 2.11.2 System Description 2.11-32.11.3 Testing 2.11-152,11.4 Mission Results 2,11-212.11.5 Conclusionsand Recommendations_ 2.11-242.12 CREW STATION AND STOWAGE 2.12-12.12.1 InternalArrangement and In-FlightMaintenanceProvisions 2.12-I2.12.2 Cuntrols and Displays 2.12-II

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iI AIRLOCK MODULE FINAL TECHNICAL REPORT aoc Eo899 VOLUMEI! TABLEOFCONTENTSVOLUMEI CONTIN.UEDt 2.12.3 Visibility 2.12-20l 2.12.4 Extra Vehicular Activity 2.12-23

_ 2_12.5 Lighting 2.12-33.12.6 Stowage 2.12-492.13 CREWTRAINERS 2.13-12.13.1 NASATrainer : 2.13-12.1:1.2 Zero-G Trainer 2.13-132.13.3 Neutral BuoyancyTrainer 2.13-16

' 2.13.4 Skylab Systems Integration Equipment 2.13-272.14 EXPERIMENTS 2.14-12.14.1 H_9 NitrogenRecharge Station - 2.14-12.14.2 $193 Experiment 2.14-52.14.3 D024 Experiment 2.14-72.14.4 5230 Experiment 2.14-92.14.5 Radio Noise Burst Monitor 2,14-112.14.6 Conclusions and Recommendations 2.14-122.15 GROUNDUPPORTQUIPMENT 2.15-12.15.1 GSECategories and Classifications : 2.15-4

_ 2.15.2 GSEDevelopmentand Design Requirements 2.15-52.15.3 GSEDesign Description 2.15-112.15.4 GSECertification 2.15-48

* 2.15.5 Conclusions and Recommendations 2.15-52' 2.16 SYSTEMSUPPORTCTIVITIES 2.16-1, 2.16.1 Electromagnetic CompatibilityRequirements 2.16-1:: 2.16.2 Sneak CircuitAnalysis 2.16-9' 2.16.3 Haintenance Technology Support 2.16-12; 2.16.4 ProgramSpares Support 2.16-16;-t

SECTION3 RELIABILITYPROGRAM 3-1:.- 3.1 METHODOLOGY 3-1_ 3.2 DESIGNEVALUATION 3-2 '.!, 3.3 "- SUPPLIEREVALUATION 3-11_ 3.4 TESTREVIEW 3-112:_" 3.5 NONCONFORHANCEEPORTING,ANALYSIS,AND_ . CORRECTIVECTIONCONTROL 3"13

3.6 ALERTINVESTIGATIONS 3-17

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-I AIRLOCK MODULE FINAL TECHNICAL REPORT MOOE0899 VOLUME!ABLEOF CONTENTSOLUMEI CONTINUED! 3.7 MISSIONRELIABILITY 3-19[ 3.8 CONCLUSIONSNDRECOMMENDATIONS 3-19

SECTION4 SAFETYPROGRAM 4-1" 4.1 GROUNDERSONNELNDCREWSAFETY 4-1: _ 4.2 INDUSTRIALSAFETY 4-9_:i 4.3 CONCLUSIONSNDRECOMMENDATIONS 4-11

,_! SECTON 5 TESTPHILOSOPHY 5- I5.1 TESTREQUIREMENTS .... 5-15.2 VERIFICATIONTESTPHILOSOPHY 5-6

{ 5.3 U-] VERIFICATIONTESTING 5-22I :"li 5.4 U-2 VERIFICATIONTESTING 5-36. i 5.5 MISSIONSUPPORTESTING 5-38

_" , 5.6 CONCLUSIONS 5-39/

SECTION6 ENGINEERINGROJECTMANAGEMENT 6-16. ] PLANNINGANDSCHEDULING _6-36.2 ENGINEERINGREVIEWS 0-96.3 PROJECTREVIEWS 6-156.4 ENGINEERINGREPORTS 6-20

,': 6.5 INTERFACECOORDINATION _ 6-236.6 CONFIGURATIONANAGEMENT 6-31I, SECTION7 MISSIONOPERATIONSSUPPORT ' 7-I! c-7.1 MISSIONOPERATIONSLAN 7-27.2 MISSIONSUPPORTRGANIZATION 7"37,3 MISSIONSUPPORTACILITIES 7-67.4 MISSIONSUPPORTCTIVITY 7-297,5 CONCLUSIONSNDRECOHHENDATIONS 7-43

SECTION8 NEWTECHNOLOGY 8-1

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AIRLOCK MODULE FINAL TECHNICAL REPORT MOCEOe99VOLUMEI

TABLEOF CONT_TS_VOL.JI_E1I COWr..N.UEDSECTION9 CONCLUSIONS 9-1

9.1 AIRLOCKHISSIONPERFORIM.NCE 9-19.2 . AlP,LOCKEND-OF-RISSIONSYS!EHSSTATUS 9-3"9.3 AIRLOCKPROGRANLESSONSEARNED" 9-4

APPENDIXA AlP,LOCKCONTROLNDDISPLAYPANELS A-1APPENDIXB NATRIXOFTESTINGREQUIREDOQUALIFYAlP,LOCK

EQU|PNENT B-1APPENDIXC DEVELOPNENTNDQUALIFICATIONESTREQUESTNDEX C-1APPENDIXD ECS/TCSSTUTESTREQUESTNDEX D-1APPENDIXE_ NISSIONDISCREPANCIES E-1APPENO[X END-OF-NISSIONSTATUS F-1APPENDX G ACRONYRSNDABBREVATIONS G-1APPEND] X H REFERENCES H- 1

APPENDIX I ABSORBTION CAPACITY OF ACTIVATED CHARCOAL I-1APPENDIX J FINAL TEC:_NICAL REPORT FOR THE PAYLOAD SHROUD J- I

NOTE: The Final Technical Report for the Payload Shroud ts presented tn-- HOCReport G4679A.


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AIRLOCK MODULE FINAL TECHNICAL REPORT MDCE0699 VOLUMEI

LIST OF F]'GLIRES

fIGURENO. TITLE PAGE1-1 Airlock ModuleGeneral Arrangement 1-31-2 Atrlock Components 1-41-3 Skylab Cluster Configuration - MannedMission 1-51-4 Skylab LaunchConfigurations 1-6!-5 Skylab SL-1 and SL-2 Launches 1-71-6 Skylab Mission:Profiles _ . _ 1-82.1-1 SpendStage Experiment Support Module (SSESM) 2.1-22.1-2 Wet WorkshopConfiguration Evolution from Spent Stage_, Experiment Support Module 2.1-42.1-3 Orbital Wet WorkshopConfiguration (UnmannedLaunch) 2.1-52,1-4 Apollo Applications Program- Wet WorkshopConfiguration 2,1-72.1-5 Airlock ModuleArrangement (AAP-2) ,2.1-82.1-6 WorkshopMission Proftle (AAP) 2.1-92.1-7 Airlock Weight GrowthHistory 2.1-1i2.2-1 Airlock Module .. 2.2-22.2-2 STS and Radiators 2.2-52.2-3 Tunnel Assembly 2.2-72.2-4 Internat Hatch 2.2-82.2-5 EVAHatch 2.2-102.2-6 Flexible Tunnel Extension 2.2-112.2-7 Support Truss Assembly 2.2-12'2.2-8 Dsployment Assembly 2.2-132.2-9 ATMRtgidtzlng Hechanism 2.2-142.2-10 Oeploymnt AssemblyRotation Mechanism 2,2-152,2-11 DeploymentSystemRelease Hechantsm 2,2-162.2-12 Deployment SystemPyro SystemSchematic 2.2-172.2-13 Deployment SystemTrunnion Mechanism 2.2-182.2-14 DeploymentSystemLatching MeChanism 2.2-20:2.2-15 Fixed Atrlock Shroud 2;2-212.2-16 AM/MDA/DAMechanical SystemsTest Flow 2.2-252,2-17 AH, AM/HDA,and OAStacking and Alignment 2.2-26_r2.2-18 Ffxed Alrlock ShroudMaximumDatly Temperature 2.2-32

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AIRLOCK MODULE FINAL TECHNICAL REPORT MDCE0899 VOLUME IILISTOF FIGURESCONTINUED

2.3-I WeightMonitoringPlan 2.3-22.3-2 AirlockWeightHistory 2.3-32.3-3 Weighingand Centerof GravityDeterminationFlow 2.3-42.3-4 AirlockModdleActualWeightand BalanceResultsversus2.3-5 U-I LaunchWeightversusMaximumSpecificationWeight 2.3-G2.4-I ThermalControlInterface 2.4-22.4-2 Th)rmalDesignData 2.4-62.4-3 EREP DesignManeuvers 2.4-72.4-4 ControlMomentGyrosDesaturationManeuvers 2.4-72.4-5 KohoutekCometViewingDesignManeuvers..... 2.4-82.4-6 ThermalControlSystemDesignRequirements 2.4-82.4-7 ExternalDesignHeat LoadConditions- Orbital 2.4-I02.4-8 InternalDesignHeatLoads 2.4-II2.4-9 AM CompartmentHeat Loads 2.4-122.4-I0 ExternalSurfaceTemperatureProfileDuringLaunchandAscent 2.4-142.4-II CoolantSystem 2.4-16

I 2.4-12 ECS ControlPanel203 2.4-172.4-13 CoolantSystemFlow Performance 2.4-182,4-14 TypicalCoolantReservoirCharacteristics 2.4-202.4-15 ColdplateMountedEquipment 2.4-222,4-16 ColdplateLocations 2.4-242.4-17 Pad and VAB GroundCoolingSystem 2.4-252,4-18 Pre-LiftoffCoolingRequirements 2.4-272.4-19 GroundCoolingRequlrementsfor a HoldAfter rerminationof NormalGroundCooling 2.4-28_,4-20 GroundCoolingSystemCoolantVolumeCompensatorCharacteristicsurves 2,4-302.4-2! RadiatorCapacity 2,4-312.4-22 RadiatorPerformancefor EREPManeuvers(60 Arc Pass) 2.4-332.4-23 RadiatorPerformancefor EREPManeuvers(12O Arc Pass) 2.4-342.4-24 Radi'atortretchout- LookingOutboard 2.4-352.4-25 ThermalCapacitor 2.4-36

:t 2.4-26 CoolantSystemPerformance 2.4-37_ 2,4-27 SL-4 CoolantReserviclng 2,4-39

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AIRLOCK MODULE FINAL TECHNICAL REPORT MDC E0899 VOLUMEIILISTOF FIGURES-CONTINUED

FIGURENO. TITLE PAG___E2.4-28 CoolantReservicingPressureCharacteristics 2.4-412.4-29 CoolantReservicingMass Characteristics 2.4-422.4-30 ATI_C&D Panel/EREPCoolingSystenl 2.4-432.4-31 EREPElectricalLoads(60 Arc Pass) 2.4-442.4-32 EREPElectricalLoads(12O Arc Pass) 2.4-4a2.4-33 PowerConditioningGroupWasteHeat- Two SolarArray

Wings 2.4-472.4-34 PowerConditioningGroupWasteHeat- SolarArray Wing #I 2.4-48' 2.4-35 PredictedBatteryTemperatures Two SolarArrayWings 2.4-492.4-36 _,ed,ictedatteryTemperatures- SolarArrayWing #1 2.4-.492.4-37 _i'_IDAhermaiCoatingDesignValues 2.4,1-502.4-38 DA and FAS ThermalCoatingDesignValues 2.4-512.4-39 VehicleThermalInsulation 2.4-532.4-4.0 EquipmentThermalInsulation 2.4-552.4-41 Wall HeaterLocation/Thermostatnstallation 2.4-572 4-42 MolecularSieveOverboardExhaustDuct Heater - 2.4-592 4-43 ThermalControlSubassemblyTests 2.4-65"2.4-44 CoolantSystemTest History- MDAC-E 2.4-67

- 2.4-45 ATM C&D Panel/EREPCoolingSystemTestHistory- MDAC-E 2.4-682.4-46 CoolantSystemRequirementVerification 2.4-742.4-47 CoolantSystemPump/InverteFlowTests- MDAC-E 2.4-762.4-48 CoolantSystemPump/InverterFlowTests - KSC 2.4-772.4-49 ATM C&D Panel/EREPH20 CoolingSystemRequirement

Verification 2.4-782.4-50 ThermalControlCoatingRequirementVerification 2.4-792.4-51 AM U-l RadiatorSolarReflectanceTest Results- KSC 2.4-802.4-52 Thermal/MeteoroidurtainsGoldCoatedSurfaceEmissivityMeasuredat MDAC-E 2.4-812.4-53 CoolantFlowrate 2.4-I002.4-54 CoolantSystemPump InletPressuPes 2.4-I012.4-55 CoolantSystemCoolanolMass _, 2.4-I022.4-56 CoolantLoopHeatLoads 2.4-I052.4-57 CoolantTemperaturesDuringRadiatorCooldown 2.4-I06

, 2.4-58 ThermalCapacitorPerformance 2.4-1072.4-59 SL-2 Radiator/ThermalapacitorTemperatures 2.4-I082.4-60 SL-3 Radiator/ThermalapacitorTemperatures 2.4-I08

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_ AIRLOCK MODULE FINAL TECHNICAL REPORT MDC E0899 VOLUME II! LIST OF FIGURES CONTINUEDi FIGURE NO. TITLE PAGEi 2.4-61- SL-4 Radiator/Thermal Capacitor Temperatures 2.4-108t1 2.4-62 Radiator/ThermalCapacitor Temperatures _uring a

Kohoutek Viewing Maneuver 2.4-1102.4-63 Radiator/ThermalCapacitor Temperature During an EREPZ-LV Maneuver 2.4-1102.4-64 Effect of SL-I Attitude on Airlock Module Temperature 2.4-115

I 2.4-65 STS Wall Temperature 2.4-_16} 2.4-66 STS Gas Temperature at Mole Sieve - Compressor Inlet 2.4-117! 2.4-67 FAS Skin Temperature - Solar Inertial Attitude. 2.4-118! 2.4-68 02 Tank Temperature - Solar Inertial Attitude 2.4-I19_ 2,4-69 N2 Tank Temperature - Solar Inertial Attitude 2.4-120

2.5-I Airlock EnvironmentaiControl Interface " 2.5-22.5-2 Gas System 2.5-102.5-3 Airlock Cluster Purge and Cooling Requirements 2,5-II2.5-4 STS Window Assembly 2.5-132.5-5 Ozygen and Nitrogen Tanks 2.5-142.5-6 02/N 2 Control Panel 225 2.5-162.5-7 Cabin Pressure Regulator Flowrate Characteristics 2.5-212.5-8 Control and Alarm Ranges for Two Gas Control Systems _.5-222.5-9 Forward Compartment Pressure Relief Valve 2.5-232.5-10 Atmospheric Control System 2.5-242.5-11 Dewpoint Temperature During Activation 2.5-25

'I 2.5-12 Cluster Dewpoint Temperature Range After Activitation 2 5-262.5-13 ECS Control Panel 203 2.5-282.5-14 Molecular Sieve Condensing Heat Exchanger Control Panels 2.5-292.5-15 Molecular Sieve Condensing Heat Exchanger Air Flow Valve 2,5-302.5-16 Condensing Heat Exchanger 2.5-312.5-17 Single Molecular Sieve System 2,5-332,5-18 Molecular Sieve Vent Valves and Bed Cycle N2 Supply Valves 2.5-362.5-19 Molecular Sieve A Valve Control Panels 226 and 228 2,5-372.5-20 Molecular Sieve Operating Instructions 2.5-382.5-21 PPCO2 Sensor 2.5-392.5-27 Molecular Sieve A PPCO2 Sensors 2.5-402,5-23 PPCO2 Sensor Recharge Requirements 2.5-412.5-24 Tunnel Stowage Container (01) 2 5-42

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FIGURE NO. TITLE PAGE2.5-25 Ventilation Flowrates Delivered to OWS 2.5-432.5-26 Ventilation Flowrates Deliverod to MDA 2.5-442.5-27 Atmospheric Cooling Capability- Condensing Heat ExchangerFlow Diverted to OWS 2.5-452.5-28 Atmospheric Cooling Capability - Condensing Heat ExchangerFlow Diverted to MDA 2.5-462.5-29 AM Condensate System 2.5-482.5-30 CondensateControl Panel 216 2.5-492_5-31 Effect of Cabin Gas Leakage on OWS Holding TankPressurization 2.5-502.5-32 AM Condersate Tank Pressure Buildup 2.5-512.5-33 Water Separator Plate Servicing 2.5-53

, 2.5-34 In-flight Water Servicing 2.5-54_ 2.5-35 Atmospheric Control System Test History - MDAC-E 2.5-65_ 2.5-36 Gas System Test History - MDAC-E 2.5-66I 2.5-37 Condensate System Test History - MDAC-E 2.5-67_ 2.5-38 ECS Gas System RequirementVerification 2.5-72_ 2.5-39 ECS Atmospheric Control System RequirementVerificatio_ 2.5-78

2.5-4C ECS Condensate System Requirement Verification 2,5-81, 2.5-41 Compartment Differential Pressures During Ascent 2.5-89

2.5-42 Prelaunch Loading of Airlock Module 02 and N2 Tanks 2.5-902.5-43 02 and N2 Consumable Usage Summary 2.5-912.5-44 Gas System Regulated 02 Pressures 2.5-93

' 2.5-45 Gas System Regulated N2 Pressures 2.5-932.5-46 Regulated N2 Pressures During SL-3 2.5-942.5-47 Regulated N2 PressuresDuring SL-4 2.5-9'"_.5-48 Cluster Pressurization Prior to SL-3 2.5-962 5-49 Cabin Total and Oxygen Partial Pressure Control 2.5-I002.5-50 SL-2 Dewpoint History 2.5-1022.5-51 SL-3 Dewpoint History 2.5-1032.5-52 SL-4 Dewpoint History 2.5-I042.5-53 _olecular Sieve A Inlet CO2 Partial Pressure 2.5-I062.5-54 Molecular Sieve Performance 2.5-1072.5-55 Summary of Molecular Sieve Bed Bakeouts During Flight 2 5-I082.5-56 Airlock Module Fan Performance 2.5-1092.5-57 Interchange_'_rtFan Flowrate ?.5-III

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FIGURE NO. TITLE PAGE2.5-58 Aft Compartment Cabin Heat Exchanger Fan Flowrate 2.5-1122.5-59 Heat Removal from Cabin Atmosphere 2.5-1142.5-60 SL-2 Condensate System Activation 2.5-1152.5-61 Condensate System pressure _uring EVA on DOY 158 2.5-1162.5-62 CondensateSystem Pressur_ :_ringCWS Holding Tank Dump 2.5-]]72.5-63 SL-3 Condensate System Acz_vation 2.5-]182.6-] IVA Control Panel 2]7 t 2.6-52.5-2 EVA No. I Contro_ Pane] 3]7 2.6-6_.6-3 EVA No. 2 Control Pane] 323 2.6-7_.o-- Lock Compar[ment Control Pane] 316 2.6-82.6-5 Airlock Suit Cooling System 2.6-102.6-6 Lighting, Cautien and Warning Control Panel 207 2,6-]I2.6-7 System 1LCG R_servoir Pressure Valve Panel 223 2,6-132.6-8 LSU Stowage in AM 2.6-142.J 9 Liquid/Gas Separator 2.6-15_.6o]0 Tunnel Stowage Container 305 2.6-162.6-]] SbS Water Flowrate Performance 2.6-172.6-12 Suit Cooling System Performance 2.6-192.6-13 Suit Cooling System Performance 2.6-202.6-14 Suit Cooling System Performance 2.6-222.6-]5 Lock DepressurizationValve and Forward Hatch 2.6-252.6-16 Lock/Aft Compartment Ventin$ for EVA 2.6-262.6-17 EVA Lock/Aft Ce=npartmentRepressurizatioa 2.6-262.6-18 EVA rock/Aft RepressurizationProfile - Alternate 2.6-272.6-]9 Suit Cooling System Test History - MDAC-E 2.6-342.6-20 Suit Coo)ing System Requirement Verification 2.6-382.6-21 EVA/IVA 02 Supp)y System Requirement Verification 2.6-402.6-22 EVA/IVA Gas Delivery System 2.6-422.6-23 EVA Lock Pressure Control Valve RequirementVerification 2.6-432.6-24 Summary of Suit Cooling System Operation 2.6-472.6-25 Suit Cooling System Performance - DGY 158 EVA 2.6-482.6-26 Suit Cooling System Performance - DOY 326 EVA 2.6-492.7-] Module Layout - Solar Array Group 2.7-52.7-2 AM EPS Equipment Location 2,7-6

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AIRL OCK MODULE FINAL TECHNICAL REPORT MDc EO89_J VOLUME it.LIST OF FIGURES CONTINUED

FIGURE NO. TITLE PAGE2,7-3 PCG Component Location - Battery Module 2 -72.7-4 Typical PCG Circuit - Controls and Instrumentation 2.7-82.7-5 Battery Charger Functional Block Diagram 2.7-I02.7-6 Ampere-Hour Return Factor versus Battery Temperature 2.7-12

" 2.7-7 Battery Charging Mode Curves 2.7-142.7-8 Voltage Regulator Block Diagram 2.7-172.7-9 Voltage Regulator and Current Characteristics 2.7-182.7-10 Typical Voltage Regulator Total Output Characteristic 2.7-202.7-ii Battery Output Function Diagram 2.7-222.7-12 SimplifiedOrbital Assembly Power DistributionDiagram 2.7-242.7-13 Simplified Bus Control and Monitor Diagram 2.7-262.7-14 Shunt Regulator 2.7-312.7-!3 Continuous PCG Power DeterminationOiagrams 2.7-352.7-16 Battery State-of-Chargeversus Orbital Time for VariousLoad Conditions 2.7-362.7-17 Regulator Output Voltage and Current Curves Z.7-402.7-18 AM EPS Testing _istory 2.7-452.7-19 MDAC-EBattery Test Parameters 2.7-592.7-20 Maximum Load Capabilities of PCG's 2.7-642.7-21 Electrical Power System - SST Flow Diagram 2.7-732.7-22 Calculated AM EPS Bus Power Capability versus Day-of-Year 2.7-862.7-23 AM EPS Bus Power for SL-2 to SL-3 Storage Period 2.7-882,7-24 AM EPS Bus Power Capability versus Day-of-Year - SL-3 Mission" 2.7-892.7-25 AM EPS Bus Power for SL-3 to SL-4 Storage Period 2.7-92?.7-26 AM EPS Bus Power for SL-4 Manned Mission 2.7-942.7-27 Typical PCG Orbital Parameter Variations 2.7-972.7-28 Limitation of AM Battery Charge Voltage

SL-2 and 3 Mission Composite 2.7-992.7-29 Ampere-Hour Meter State-of-ChargeIntegration 2.7-I002.7-30 Battery State-of-Charge Integration 2,7-1042.7-31 PCG #3 Battery State-of-ChargeAccuracy 2.7-I062.7-32 PCG #8 Battery State-of-Charge Recovery 2.7-II02.7-33 SL-2 Mission Composite AM Battery Discharge CharacLeristic 2.7-III2.7-34 PCG #6 Inflight Capacity Discharge 2.7-I152.7-35 PCG _8 Inflight Capacity Discharge 2,7-116


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FIGURE _0. TITLE PAGE2.7-36 SL-3 Composite AM Battery Disoharge C_aracteristic 2.7-!172.7-37 SL-4 Composite AM Battery Discharge (,haracteristic 2.7-1192.7-38 PCG _6 InflightCapacity Discharger 2,7-1202.7-39 Typical 3800 Cycle Discharge Profile for Indicated Batteries 2.7-1222.7-40 Typical 3_00 Cyc]e Discharge Profile_for Indicated Batteries 2.7-1232.7-41 Typical Voltage Regulator Input and Output Voltages 2.7-1242.7-42 AM Bus Regulation Curves (Typical) 2.7-1262.7-43 SAS _4 Current Paths 2.7-1372.7-44 Simulated "SAS #4 Return Wire Short" Test Results 2.7-1422.8-I SL-| and SL-2 Major Sequential Events 2.8-22.8-2 IU/OWS Switch Selector System 2.8-32.8-3. Discrete Latch Actuator System 2.8-62.8-4 Payload Shroud ElectricalOrdnance 2.8-72.8-5 Payload Shroud Thrusting Joi'ntSystem- 2.8-82.8-6 Payload Shroud Component Location 2.8-I02.6-7 Payload Shroud Electrical-Commands/Functions 2.8-II2.8-8 Payload Shroud Electrical Jettison Diagram 2.8-132.8-9 System Testing - Payload Shroud Jettison Subsystem 2.8-142.8-I0 Summary of Launch Site Significant Ordnance and DeploymentProblems 2._--152.8-II Payload Shroud Jet ison 2.8-162.8-12 Typical EBW Firing Unit Charge/Trigger Curve (Telemetry Data) 2.8-172.8-14 Payload Shroud Jettison Sequence 2.8-182.8-14 ATM Dep!ovment Electrical - Commands/Functions 2.8-212.8-15 ATM Deployment Diagram 2,8-222.8-16 System Testing - ATM Deployment Subsystem 2,8-232.8-17 ATM Deployment 2.8-252.8-18 Typical EBW Firing Unit Charge/Trigger Curve (Telemetry Data) 2.8-262.8-19 ATM Deployment Sequence 2.8-26

, 2.8-'20 Discone Antenna Deployment Diagram 2.B-292.8-21 Discone Antennas 2.8-302.8-22 Deploy Bus Control Diagram 2._-332.8-23 Sequential Bus Control Diagram 2.8-342.8-24 RefrigerationSystem Radiator Shield Jettison Diagram 2.8-372.8-25 Refr;'_ration System Radiator Shield Jettison 2.8-37

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FIGURE NO. TITLE PAGE2.8-26 Refrigeration System Control Diagram 2.8-382.8227 OWS RefrigerationRadiator Temperature 2.8-392.8-28 OWSHabitation Area Vent Valves 2.8-412 8-29 OWS Waste Tank Vent Diagram 2.8-412.8-30 OWSPneumatic Sphere Dump Diagram : 2.8-422.8-31 OWS Solenoid Vent Valves (HabitationA_ea) Diagram 2.8-432.8-32 OWSHabitation Area Vent 2.8-442.a-33 OWS Waste Tank Vent . 2.8-452.8-34 Pneumatic Sphere Dump 2.8-462.8-35 Meteoroid Shield Deployment Diagram 2.8-48_2.8-36 OWS Beam Fairing Deployment Diagram 2.82502.8-37 OWSWing Deployment Diagram 2.8-512.8-38 ATM SAS Dep_oyment/ATMCanister Release 2.8-542.8-39 ATMSAS/Caniste, Co,ands/Functions 2.8-55 "2.8-40 ATM Activation/Co trol 2.8-582.8-41 Typical AM CRDUCircuit 2.8-592.8-42 MDA Vent Valve Functions 2.8-612.8-43 Typical Vent Valve Control Circuit - 2.8-612.8-44 MDA Vent Valve Operation . 2.8-632.9-1 Saturn Workshop Instrumentation System 2.9-22.9-2 InstrumentationRegulated Power Subsystem 2.9-122.9-3 PCMMultiplexer/Encoder 2.9-142.9-4 PCM Multiplexer/EncoderChannel Capability 2.9-152.9-5 Recorded Data Signal Flow 2.9-182.9-6 Mission Data Processing Flow (DRR MagneticTape) 2.9-272.9-7 Instrumentation System Test Flow (MDAC-E) 2.9-292.9-8 InstrumentationSystem Test Flow - KSC 2.9-34

, 2.9-9 InstrumentationSystem Summary First Mission 2.9-372.9-10 InstrumentationSystem Summary - Second Mission ,,, 2.9-39? 9-II InstrumentationSystem Summary - Third Mission . 2.9-40 :2.10-I Con_unications System 2.10-32.10-2 CommunicationaSystem Test Flow - MDAC-E 2.10-42.10-3 Communications System Test Flow - KSC 2.10-52.10-4 Orbital Assembly Audio Subsystem:' 2.10-9

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AIRLOCK MODULE FINAL TECHNICAL REPORT MOCE0899 VOLUMEILIST OF FIGURES CONTINUED

FIGURE NO. TITLE PAGEc.12-24 StowageLockerM30I 2.12-54Z.12-25 Stowage Locker M303 2.12-552.12-26 Stowa(jeLocker M305 2.12-562.12-27 Stowage Locations M308 and .M313 2.12-572.12-28 Stowage Locations M3IO and M311 -,; 2.12-582.12-29- Stowage Location M326 2.12-592.12-30 Film Transfer Boom/Hook Stowage 2.12-602.13-1 Early Airlock Trainer 2.13-2 -

- 2.13-2 The NASA Trainer 2.]3-3, 2.13-3 NASA Trainer Connector Panel 2.13-5

2.13-4 NASA Trainm- - Initial Support Stand 2,13-52.13-5 EVA Stand Modifications " - 2.13-72.13-6 EVA DevelopmentStand at tlSFC 2.13-92.13-7 Zero-G Trainer 2,.13-142.13-8 Zero-G Trainer - EVA Hatch Damper 2.13-15

_ 2.13-9 Zero-G Trainer Used as a High Fidelity One-G Trainer 2.13-172.]3-10 Original Neutral Buoyancy Trainer 2.13-17-

_ 2_,13-II Airldck Neutral Buoyancy Trainer on Rotating Dolley 2.13-192.13-12 Neutral Buoyancy Trainer 2.13-202.13-13 Neutral Buoyancy Trainer in JSC Facility 2.13-212.13-14 Model of Neutral Buoyancy Trainer in MSFC Facility 2.13-232.13-15 Neutral Buoyancy Trainer - Crew Training 2.13-242.13-16 Neutral Buoyancy Trainer - _lissionSupport Activity 2.13-262.14-I Experiment Locations 2.14-22.14-2 M509 Recharge Station and liold-downBracket 2,14-42.14-3 , $193 Package Installation 2.14-62.14-4 'D024Thermal Control Coating 2,14-8 .2.14-5 $230 Experime.nt 2.14-I0

2.15-I Design Criteria for Handling Equipment 2.15-72.15-2 Airlock }n Vertical Transporter 2.15-122.15-3 flaredAM/MDA in Horizontal Trailer 2,15-13

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FIGURENO. TITLE PAGE2.15-4 FAS in Transporter- LaunchAxis Horizontal 2.15-14

: 2.15-5 MatedDA in Transporter 2.15-152.15-6 AM VerticalTransporterand AssociatedGSE 2.15-172.15-7 AM/MDAHorizontalHandlingTrailer 2.15-lg2.15-8 MatedAM/MDABeingLoadedon ShippingPallet 2,15_202.15-9 FixedAirlockShroudTransporterand AssociatedGSE 2.15-21, 2.15-I0 FixedAirlockShroudAir Shipment 2.15-212.15-II DA Transporter 2.15-23

: 2 15-12 DeploymentAssemblyAir Shipment 2.i5-242.15-13 FAS/MDA/AM/DA/PSCylinderStackHandling 2.15-252,15-14 Accessand HoistingProvisions 2.15-272.15-15 PayloadShroudAccessPlatformTrialFit 2.15-282.15-16 AM/MDAElectrical/ElectronicSE - MDAC-E 2.15-302.15-17 O2/N2 Servicingand AM/MDAN2 Purge 2.15-412.15-18 02/N2 Servicingand AM/MDAN2 PurgeSchematic 2.15-432.15-19 AirlockGroundCooling 2.15-44

_ 2.15-20 AirlockGroundCoolingSchematic 2.15-452.15-21 AltitudeChamberFireSuppression 2.15-472.16-I ElectroMagneticCompatibilityTest Flow 2.16-52.16-2 Tools and InflightSpares 2.16-133-I FailureModeand EffectAnalysisReport- SamplePage 3-43-2 CriticalItemListReport- SamplePage 3-53-3 Nonconformanceeporting,Analysisand CorrectiveAction 3-143-4 MDAC-EAlert Summary 3-185-I Test ProgramTradeStudy 5-35-2 AirlockTest ProgramTradeStudyResults 5-35-3 Test ProgramDocumentation 5-55-4 Processfor QualificationProgramDefinition 5-75-5 FlightHardwareCriticalityCategory 5-85-6 SuggestedNumberof QualificationTest Articles 5-85-7 EnduranceTesting 5-9

, 5-8 OverallPlannedTest Flow 5-13-' 5-9 PlannedTest Flowat MDAC-E 5-14

5-10 TotalAcceptanceTest Publications(U-Iand U-2) 5-17xxi

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FIGURENO. TITLE PAGE5-11 TypicalMajor FestDocumentPreparationSec.uence 5-185-12 AcceptanceTest Documentationree 5-205-i3 GeneralizedOverallTest Flow " , 5-215-]4 AM/MDA/FAS/DAMating Activity 5-26 .-5-15 FAS and DA Test Flow FollowingSoft-MateActivity 5-285-16 U-1 '4DAC-ETest Flow - Planned 5-295-17 U-I MDAC-ETestFlow - Actual 5-315-18 U-I LauncnSiteTest Flow - Planned 5-325-19 U-I LaunchSiteTest Flow - Actual 5-355-20 U-2 MDAC-ETest Flow - Actual 5-376-I Engineering;4asterchedule- Sample 6-46-2 AcceptanceTestMasterSchedule- Sample 6-66-3 Engineering Job Saeet Flow Plan 6-86-4 System/Suosystem Design Reviews 6-96-5 Verification Documentatin Relationsi,p 6-21__6-6 InterfaceControlDocument3aselineSubmittals 6-246-7 FlightVei_iclenterfaces 6-25,6-8 GSE Intarfac_s :. : ' 6-266-_ AirlockInterfaceControlDocumentCiiangectivity 6-276-1O Technical Requi rements Documentation 6-326_11 Class I ChangeFlowPlan 5-367-1 Example Airlock Projec,, Mission Communications andResponsibilities_I:.Iesignand TechnicalGrouos) 7-57-2 MDAC-EMissionOperationsCommunicationsacility 7-77-3 SystemsTrend Charts- CommCenter 7-87-4 SystemsSchemat!csand TrendCharts- Comm C-_nter 7-97-5 U-2 BackupFlightHardware 7-13

,, 7-6 SkylabSTU/STD;'Ilock Diagram ,. 7-16: 7-7 AMIOWS/ATM/MDAimulatoralockDiagram' 7-177-8 STU/STD_IC_nmand Control C_nsole 7-18

7-9 STU/STD_Iata AcquisitionSystem 7-18_: 7-10 TV Equipment. and S-_and Ground Station 7-18

7-11 CommandControlConso'len_ut/3utputglockDiagram 7-20._ 7-12 Da;aPresentationTechniques 7-23

7-13 ,',irlock ECS/TCSSTU Capabilities 7-25xxii


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FIGURE NO. TITL..___E PAG__7-14 ECS/TCSSTU Cabin EnvironmentChamber 7-267-15 ECS/TCSSTU Exten=alEnvironmentChamberSimulationSetup 7-267-16 ECS/TCSSTU Test Configuration 7-277-17 VendorsSupportingMDAC-EMissionOperations 7-32/-18 AirlockProjectMissionOperationsSupportCoverage 7-338-1 Pup1 snedNASATechnology 8-28-2 Deploymeht AssemblyLatching Mechanism 8-2

1 This documentconsists of the following pages:VOLUMEI

- _ _ TitlePage_ iii through xxiii " 2.4-Ithrough 2.4-1241-1 through 1-22 2.5-1 through 2.5-1232.1-1 through 2.1-12 2.6-1 through 2.6-562,2-1 through 2.2-32 2.7-1 through 2.7-146_ 2.3-1 through 2.3-6 2.8-1 through 2,8-642.9-1 through 2.9-44

VOLUMEIITitle Page 7-1 through7-44iii through xxiii 8-1 through8-4: 2.10-1 through 2.10-78 9-1 through 9-14; 2.11-1 through 2.11-26 A-1 through A-20/ 2.12-1 through 2.12-64 B-1 through B-14:' 2.13-1 through 2,13-28 C-1 through C-242.14-1 through 2.14-12 D-1 through D-122_15-1 _hrough 2.15-54 E-1 through E-16

:' 2.16-1 through 2.16-18 F-1 through F-12:, _ _., 3-1 through 3-20 G-1 through G-8_,o,',. 4-1 through 4-12 H-1 through H-8:-;:: 5-1 through 5-40 I-1 through I-4,:-', 6-1 through 6-42 1-11i through _-65

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i AIRLOCK MODULE FINAL TECHNICAL REPORT MDC E0899 VOLUME III Z.lO COMMUNICATIONSYSTEM

The Communicationsystemwas requiredto sendand receiveinformationbetween: Crewmembersin the SWS (AM/MDA/OWS)r on EVA. Crewmembersand STDN.e SWS Systemsand STDN. AM and CM duringrendezvous.

Informationoriginatingin the SWS which consistedof voice,instrumentationdata, and _elevision,necessitateddownlinktransmissionto STDN in both real-timeand delayed-time.The AM transmittersere neededfor real-timeand delayed-timetransmissionof telemetrydataand for delayed-timevoice. The CM transmitterswere used for SWS real-time voice and for real-time and delayed-time television.Voiceand commandmessageuplinkinformationwas receivedfromSTDN, the commandlinkvia AM receivers,the voicevia CM receivers. The commandswere decodedin

,=.the AM and usedin the SWS to control,on-boardequipment,to uodatetiminq andto provideprintedmessagesvia a teleprinter.To facilitateCSFIto SWS rendez-vous, a VHF rangingsystemwas providedon the AM wh"'h transpondedranging

_) information to the CM. AMtracking lights were provided to facilitate visualacquisitionof the SWS duringrendezvous.

In fulfillmentof the foregoingbasiccommunicationneeds the designeffort' ,identif_iedthe subsystemequipmentrequlred,elthernewl_,esigned,off-the-shel,or modified. Specific requirements which governed equipment design and operationincludedthe following:

Compatibilityith existingSTDN and CM equipment. qaximumuse of existing flight qualifiedequipment. Redundancyto assuremissionsuccess. Capabilityof in-flightreplacementof selectedhardware.e Maximumuse of groundcontrolover equipmentoperationwith crew controlbackup. :' Minlmumencumberanceto the crew.

Antennacoveragefor all missignphases.e A goalthatthe electronicsdeslqnbe neitherthe sourceof norsusceptibleto EMI. (Referenceparagraph2.16.1).

As equipment-selectionas customerapproved,the equipment's_ertinentcharacter-tstics becamerequirements. ,

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For discussionpurposesthe Communicationsystemis dividedintosubsystemsas follows:

. Audio." Datatransmissionand antenna. Digitalcommand,teleprinter,and timereference.0 ' Rendezvus. 'This subsystemequipmentalongwith majorinterfacesare shownin block

_ diagramform in Figure2.10-1 In additionto the above subsystems a GFE supplied. , ,, televisioninputstation(TVIS)and radionoiseburstmonitor(RNBH)antennawere

installedon the AM.

"; Verificationof the Communicationsystemsdesiqnrequirementsas successfullyi_ completedduringthe courseof the testingprogram. The testin_phaseemployeda

comprehensiverogramof testsbeginningat the componentlevelin-houseand atvendorfacilitiesand continuinqthrouqhmoduleinterface,system,systemsinter-

_. face,systemsintegrationand systemssupportmode,with completionof the checkoutcycl_at the launchsite facility. At the contractorfacility,the evaluation

" and verificationof systemperformancewas accomplisheddurinasubassemblytestsandtilemajortestsas shownby Figure2.10-2. Thesetestsverifiedeachsystemindividuallyand culminatedwith all systemsbeinatestedcollectivelywith theMDA and associatedexperiments.Launchsitetest requirementsfor the-jCommunicationsystemwere definedin MDC ReportE0122,Test and CheckoutRequiremenSpecificationsnd Criteria,for use at KSC, andby the SkylabInteqratedSystem ,

. Test CheckoutRequirementsand Specifications,ocumentNo. TM 012-003-2H.Thesetest renuirementsere successfullyaccomplisheddurinnthe courseof systemleveland integratedtestingat KSC. The systemtestflowfnllowedat KSC is showninFigure 2.10-3. .,

: Missionproblemsor suspectedproblemswere usuallyresolvedby enaineerinnanalysis;however,somehardwareproblemsrequireduse of the ElectronicsSkylabTest Unit (STU)or the AM/MDAU-2 vehiclefor oDerationalconfinurationsimulationor modificationkit develonmentand validation. The AH/HDAU-2 communicationsrsystem equipment was functlo.ally ider.ttcal to AM/MDAU-1 and was nowered up

. for s_gnificantmissioneventsas wellas for probleminvestigations, ,2.10-2


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_ ANTENNASAND_ COAXIALCOMPONENTS_ ANTENNAS

e COAXIALSWITCHESRF ;- QUADRIPLEXER COAXIALCABLES RF_ DATATRANSMISSION

TELEMETRYTRANSMITTERS

DIGITALCOI_@&_U_e RECEIVERDECODERS RENDEZVOUSe COMMANDRELAYDRIVER

UNIT RANGINGe REAL TIME RELAYS e VHF TRANSCEIVERTELEPRINTER e RANGINGTONE

m INTERFACEELECTRONICS TRANSFERASSEMBLYUNIT - TRACKINGLIGHTSe TELEPRINTER , DATA& EMERGENCYVOICE VOICE e FLASHHEADSTIME REFERENCE e TRACKINGLIGHT

e ELECTRONICTIMERS ELECTRONICSe TIME CORRELATIONBUFFERSe DIGITALDISPLAYSe DIGITALCLOCK

TIMING c

F ---i --I AUDIOINSTRUMENTATONI SYSTEM 141-.-OICE--I AUDIOLOAD COMPENSATORS_(REFERENCEECTION2.9)_- -"'-.jJeSPEAKERINTERCOMSI e TAPERECORDER/ I "--'l_le EVA/IVA& IVA PANELSREPRODUCER I ...llJe CCU'S LCCU'S, AND

_ TIMING L ....... J | CONTROLHEADS

J _ EREP - ALARMCREW TONESVOICE4_1;_ _ ,,,.= PRINTEDMESSAGES CREW: v TO CREW ICAUTIONAND WARNINGSYSTEM,COMMANDS CM 4---,-- I (Reference Section 2.11) 11_ TOALLSYSTEMS / .j.

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2.10.1 Audio Subsystem

2.10.I.1 Audio Subsystem Design RequirementsThe Skylab audio subsystem was required te Drovide voice intercommunicatie

to three crewmen within the orbital assembly (OA) and/or while engaged in extra-vehicular activity, and to provide air to ground dunlex voice communicationsbetween the crewmen and the STDN. A later requirementwas added to providerecordingof voice for delayed transmission to the ground.

2.10.I.2 Audio Subsystem Description_.:.'-_ ..... _ nrpsent the evolution of desiqn chanqes that

occurred to the audio subsystem as th_ SKy,_b nroqram orooressed from its initiaconcept to the final flight configuration. These desiqn changes were necessaryto comply with the design requirement revisions that had occurred as the needsof the audio subsystem expanded. The audio subsystem reQuired four major revisiin order to arrive at the final flight configuration.

A. The initial audio subsystem was comprised of a Gemini voice controlcenter, three hardline crewmen umbilical disconnects,and two Gemini VH,,oiceLrdnsceivers,one of w,'--'ch,as mndified by retuning the receiverThe transmitter in the modified unit was not used. In addition, thecrewman headset assemblieswere to be Gemini type. The umbilical dis-connects were to be located in the Airlock, fonvard tunnel, and afttunnel, and were interconnectedvia an audio distributionsystem, tothe voice control center wt.ichprovided the necessary amDlificationand switching control to provide sidetone, modulation, and receptionof the WlF transceivers. The VHF transceivers provided communicationsbetween the AM and the docked CM, and between the A'-', and the STDN. Inaddition, the VHF transceiversprovided communicationsbetween crewmen

; |ccated _n the Airlock and crewmen operating from the prooosed EVAportable llfe SUDpOrt system (PLSS) backpack transceivers.

B. The first major change to the audio system added an audio control unitand two portable speaker intercom assemblies. The audio control unit

_ was required to provide impedance matching to enable the crewmen to" utilize Apollo-type headset assemblies and to allow the Airlock h_rd-_- line distribution system to interface with the Apollo audio system


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The hardline audio distributionsystem (ADS) was expanded to providecrewmen umbilical disconnects throughoutthe CM, t.M,MDA, AM, and r)WS.The primary voice mode utilized the ADS in conjunctionwith the Apollovoice communication system to provide communicationsamong the crewmenand between the crewmen and the STDN. The subsystem also included asecondary voice mode which utilized the ADS in conjunctionwith theAirlock VHF transceivers, voice control center and audio ccntrol unit,to provide intercom for the crewmen and a VHF simplex link between theAirlock and the STDN. The selection of the primary or secondary voice_,v'_'l'ems _::_S "" "J,,,auey properly positioningjumper cables located in theCM and STS. A backup voice duplex VHF link was also available whichpermitted emergency voice communicationsbetween the At,;nd crewmenusing the PLSS. Two portable speaker intercom assemblie_were availableand could be connected to any communicationdisconnect throughout"thecluster should headset operation be undesirable.

C. The second nlajorchange deleted the /Hrlock RF voice communicationsub-system and added a redundant hardline audio distributionsystem, twoaudio load compensators, and three additionalspeaker intercomassemblies. The deleted equipment included the VHF transceiver, VHFduplex receiver, voice control center, and the audio control unit. Thisdeletion resulted in the incorporation of a redundant ADS, with eachADS connected to a comnlandmodul- aud;o center. Each ADS included anaudio load compensat..r(ALC_ which orGvided amplification,i.-.olation,and impedance matching 6etween the SWS and the CM. In addition, theALC provided a separate amplified output to allow for w_dulation oftrack B of the AM Lape recorder to provide voice recording capability.

The audio subsystem then included five portable speaker intercom2 assemblies that could be connected to any crewman communicationdis-' connect located throughout the cluster._- D. The third major change to the audio subsystem increased the speakeri intercom assemblies (SIA) fPom f_ve units to eleven units, installed_ the SlA's in predetermined permanent locationsand incorporated',, circuitry within the SIA's to enable interface with the Caution and_ Warning syste,1for the purpose of providing visual and audible caution._ and warning alerts. Each SIA provided the capability of selection; 2.10-7


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The following presents the SWSaudio subsystemprimary electrical character--,. istics and functions: .

. Speaker Intercom Assembly Speaker and microphonecircuitry selectable between ChannelA and B ChannelA and B crewmancommunicatioPumbilical (CCU)disconnects.e Sleep modeto provide interruption of speaker and CCUearl)honeand caution andwarning tone circuitry.

Cai-1 function to enable both Channel A and B microphone circuitssimultaneously, override sleep modeof other SIA's and headsets,

,_ and provide fixed volumelevel of SIA's.._ J Redundantcaution andwarning tone circuitry for headset and&speaker functions and visual alarm indicator, c Bio-med interface between the CCUand the instrumentation system.

Separateintercommunicationr transmitkey function.I Vaicerecorderenablefunctionwith visualrecordenableindicator! B AudioLoadCompensator

m Redudant microphonelineamDlifierswitha nominalvoltagegain_f 2 dB.

e Redundantearphonelineamplifierwitha nominalvoltagegainof 3 dB into600 ohms.

m Automaticgaincontrolledtape recorderamplifierto orvideaconstantmodulationleWl to theAM taperecorders.

C, EVA/IVAPanels.. ElectricaldisconnectswhichprovidedeitherChannelA or B earphon

i and microphonelines. RedundantDC power. Bio-MedInterface,

D. CrewmanCommunicationUmbilical Interfacebetweenan SIA ChannelA or B CC'Jdisconnectand cre,_

pressuregarmentassenC)ly. Microphone,earphone,and cautionandwarningtone lines. Earphonelinevolumecontrol. Transmitand intercomfunctionswitch. Bio-Medlines. Length- 180 inches.


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E. Liqhtweiqht Crewman Communication Umbiiical (LCCLI)and Crewman CommControlHead (CCCH): Interface between an SIA Channel A or B CCU disconnect and a comm

carrieror lightweightheadsetassembly. Microphone, earphone, and caution and warning tone lines. Earphone line volume control mounted on a separate control head

whichcouldbe disconnected. No Bio-Medlines.i LCCUcouldbe connectedin seriesfor addltlonailength. Transmit and intercom function switch on control head. Length - 208.7 inches.

2.10.1.3 Audio SubsysteJ_Verification Testin9Extensive audio subsystem development testing was conducted prior to finalizing

the desin of the subsystem configuration. The tests included the followinq: Breadboard design evaluation. Bla_k box engineering prototype testing. CSM/SWS component interface testing. Audio subsystem to caution anu warning subsystem interface testing. Crew participationof audiosubsystemoperatiunincludingemergencyvoice configuration.These series of tests provided MDAC-E with the necessary infc._mationrequired

to designand developa workableaudiosubsystemwhichwould interfacewithexisting audio components located external to the AM'and Within the orbital assemblycluster.

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A comprehensive acceptance test program was accomplished encompassing oieceparts, component level and integrated systems levels. AcceDtance tests on thepiece parts and unit black boxes were performed using pre-installation acceptance(PIA) or ._cceptance test procedures (ATP) as noted. These tests included thef_l lowing equipment:

Printed circuit boards. : Speaker. Hicrophone. Speaker intercom (ATP). Audio load compensator (ATP). - Crewmancommunications umbilici. " Lighbleight crewman communications umbilical. Control head.A. The significant anomalies exper{enced during HDAC-Ecomponent testing

are delineated in the following Daragraphs. Equioment not itemizedbelow had no significant anomalies.(1) Printed Circuit Board Modules - A total of 280 PC board modules

were built and successfullytested. The orimary oroblem experienceddurinn testinn was either no _,utoutor low outout after encaosula-tion. Performanceorior to encapsulation was acceptable. Failureanalysis determined that the fault was caused by electrostaticcharnes developed durinq handlinq and encaosulation destroyingan inteqratedcircuit. Incorporationof a process soecificationchanae which delineated orecautionary handling fabrication andoackaqinn nrocedures resolved the problem. These PC board moduleswere nrimarily used in the soeaker intercom assemblies and audioload com,ensators.

(2) Speaker - A total of 85 speakers were tested. The first unitsreceived were returned to the vendor for co_ctlon of qualityproblems (e.g., bad solder, lack of epoxy, I,,_Doer packaging,and insufficientcleanliness). Subsequent units were allacceptable. ,

.

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_ (3) Microphone - A total of 64 microphones were tested andwereacceptable with the exception of four units returned to thevendor for rework. Twoof these units were contaminated withlint from cleaning swabs, one had intermittent leads, and theother exhibited poor frequency response.

,(4) SpeakerIntercom-A totalof 53 unitswere builtand success-fully tested. Resolution of the discrenancies uncovered duringtestingwere expeditedto allow for continuedproduction.Twospeakerswhichdevelopedopen circuitsduringSIA burn-inwerefoundto havediscolored_speaker,wiring.hlswas causedbyoverheatedwiringtracedto an incorrectvendorsolderingironsize (750F,S/B 6nOFmax). The rotaryswitchesusedinspeakerintercomsexhibitedintermittentopen circuits. Failureanalysisindicatedthat thewaterproofingmaterialhad contaminated

' the internal contacts causing this condition. After the manu-facturing processwas correctedthe switchdashnumberwas changedand serialnumberscontrolledto orecludethe possibilityof instal-linq contaminatedswitches.

(5) AudioLoad ComDensator- Severalfailures(oscillationdurinqhightemneraturetest)that occurreddurin_earlyATP testinqresultedin a more co_rehensive investigation of the headset line amplifieroutoutcircuit. The problemwas tracedtca transistorwhich

- failedto meet specifications,Thermalrunawayoccurredin a random" samoleof the transistorsselectedfor individualtestlnqat one

fourth of the rated.800 N4 of nower. Selecting a different vendorto suonlythe sameoart n:'mbertransistorcorrected,thisroblem,

B. Duringsystemleveltests in St. Louis (Figure2.10-2),excessivefeedbackwas presentwhen any AM/MDAspeakerintercomassemblycallswitchwas placedin the callposition. The "call"inputsto all threeSIA'swere internallyadjusted8 dB lowerthanATP values. Feedbackwas greatlyreducedby this techniqueandwas eliminatedwhen a voicesignalwas appliedto each SIA. Finalacceptanceof 'theaboveprocedurewas delayeduntila call test couldbe performedat 5 psl (altitude

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chambertest). At 5 ps_ the crewexercisedthe call circuitson theadjustedSIA'sand feedbackwas not,presentwith satisfactorycommuni-cationsbeingestablished.The requireddocumentationas changedanda!1 SIA'swere adjustedto the nev;call inputlevels.

C. Duringsystemleveltestsat KSC (Figure2.10-3),significantproblemsresultingfromthe audiosubsystemtestswere as follows:(I) Duringthe CSM/AM/MDAelectricalinterfacedockingtest,excessiv

feedbackwas observed. The volumecontrolson SIA'sat PanelsI02, If6,and 131 alonflith Panel 98 in the CM wereadjustedforless volume,eliminatinathe feedback. As the Panelll6 SIA volucontrolwas adjustedin the ODPositedirectionduringtransmis=_fromPanel131,the feedbackreturned,_rovinathe excess.feedbawas externalto the SIA's. A retestwith propervolumecontrolsettinQswas satisfactory.

(2) The rotaryswitcheson 2 SIA'swere found to be misalignedafter' mucllu_ageat KSC due to improperinstallationtechniques.' TwelveSIA'swere removedfro,_the SWS and returnedto MDAC-E

formodificationof the rotaryswitchinstallation.

, 2.10.I.4 Audio.SubsystemissionPerformanceA. SL-I/2Mission- T_,eSkylabaudiosubsystemwas activatedon DOY 146

at approximately17:32GMT and:deactivatedn OOY 173 at approximatel05:30GMT. The audiosubsystemprovidedsatisfactoryintercommunicafor the SL-2 crewand communicationsetweenthe crewand the ground.The crew utilizedthe thirteenspeakerintercomassemblieslocatedthroughoutthe AM, MDA and OWS to greatadvantageas directvoicecommunicationas possibleonlyfor shortdistancesdue to the 5 PSIAatmosphere. Delayedtimevoi'ceas of exc,:llenl_igndl-to-noiseatioand voicequality,as determinedby reviewingtaI_erecordingsmadeduringdata/voicedumpsover the St. Louis STU/STDNtrackingstation.Communicationsuringthe twoSL-2 EVAperiodswas also highlysatis-factory.

Audiofeedbackwas observedperiodicallyduringcrewutilizationof the speakerintercomassemblies..Thisconditionwas attributedtothe crewhavingtoo many SIA'soperational,the SIA speakervolume

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AIRLOCKMODULEFINAL TECHNICALREPORT MDCE0899VOLUMEIcontrolsadjustedtoo high,and the crewvoicemodulatingthe SIA atdistancesgreaterthan 12 inches. This feedbackconditiondid not ,.

_' appearto botherthe crewas theyappearedto have made no specificattemptto controlthe SIA configuration,or had they complainedaboutthe feedback. The greatestproblemwith the feedbackconditionappearedto be a slightannoyanceto the groundstationlisteners.

The follewingcommentsrelatingto the SWS audiosubsystemperfor-mancewere providedby the SL-2 crewduringthepostmissiondebriefing. The SIA volumeleveland qualitywere adequate.

' InitialCSM volumeControlsettingswere adequateand did notrequirereadjustment. The quantityand placementof SIA'swere satisfactory.The SIAlocatedat the OWS domewas not utilizedtoooften,howeveritwas requiredon severaloccasions.The SIA locatednear the bicyclein the experimentareawas not in the best location. A betterlocationmay havebeen abovetheExperimentSupportSystem. TheSIA locationby the Ml31 chairwas not required.

The typeand numberof functionson theSIA'swere adequate.However,the ICOM/PTTsw_tchand thevoiceRECORDswitchwhichwere locatedin linewi'.1each othershouldhavebeendifferenttypesor installedperpendicularto each otherprovidingdifferenttoggleaxes. Severaltimesthe voiceRECORDswitchwas inadvertentlydepressedinsteadof the ICO".'XMITwitch.

The SIA'swereutilizedapproximately0% of the time. The light-weightheadsetswere uti,lizeduringEREP passesand forSOl9operation. The comm carrierheadsetswere uti]izedduringEVA.

Microdotand zero G connectorson the SIA'sfunctionedproperly.The Microdotconnectorwas moredesirablethanthe zero G type.

Audio feedbackwas observedin both the MDA and OWS. SIA 131wasutilizedmainlyin the MDA. The othertwo unitsusuallyremainedin a "sleep"mode. In the OWS the SIA locatedin the wardroomwasutilizednmst of the time. The SIA locatedat the ScientificAirlockdirectlyabovethe wardroomcausedconsiderablefeedbackwhen it waslefton. Also the SlA'sby the MI3Ichair,the bicycleand the one

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MODULE FINAL TECHNICAL REPORT MDC E0899 VOLUME IIIRLOCKin the commander's sleep compartment caused quite a bit of feedback.The SIA in the waste management area required a higher than normalvolume setting to cause feedback. There was no feedback betweer thethree SIA's in the sleep compartments, Adjustment of the volume control setting on the activated SIA's wasnot attempted as a means to eliminate audio feedback. The procedureutilized to eliminate the squeal was to position the problem SIA'sto the "sleep" position. The call function was not utilized and, assuch, it was not known if similar feedback would have occurred inthis mode of operation. The crew suggested that a procedure, otherthan posi'tioningthe unused SIA's to the "sleep" set_cing be con-sidered for remaining manned missions.

B. SL-3 Mission - Between the time period of SL-2 return and SL-3 launch,MDAC-E investigatedthe audio feedback problem encountered during theSL-2 mission to provide a workaround technique to eIimindte audiofeedback as a problem on future Skylab missions. MDAC-E conductedaudio/acousticaltesting employing speaker intercom assemblies in theSt. Louis STU/STDN the AM/MDA U-2 and the Huntington Beach-based,OWS-2 spacecraft. This testing resulted in the formulationof aprocedure to minimize or eliminate audio feedback on the SL-3 andSL-4 missions.

The Skylab Channel A audio subsystem was activated during SL-3 on DOY 209at approximately 22:40 G_. The Channel A audio subsystem was utilizedexclusively to orovide air/nround communications,inter-communications,and delayed time voice throuah DOY 212. Crew voice transmissionswere ofsatisfactory quality thrnuahoutthis oeriod. _n DOY 212,th Channel Baudio circuit was activated for the _urnose of pr_vidinq private record-inn caoabilitvon the AM taoe recorders. The tape dumps following thisactivationresulted in unintelliaibledelayed time voice reception at thSTDN. The crew made a number of satisfactorv Channel A delayed time wictane recordinqs on DhY 213, thereby eliminatina the tape recorder as thesource of the nrohlem. The audio system was then reconfiqured to providair/nround and intercommunicationson Channel B, and private record(delayed time.voice) communicationson Channel _. On Dr)Y221 the crewconducted a troubleshootingprocedure on the Channel B audio circuit,

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PrevioussDacecrdftt_stingat St. Louison U-I had determinedthattheaudiosubsystemsi._tonevolumel._veldevelopedduringanSWS-initiatedtransmit_'mctionwould increaseapproximately5 JBabovethesidetonevolu;,,evelaeveloDeddurinqan SWS initiatedICO_function,becauseof an increasein sidetonegainof., e CSMaudiocenteraurinqtransmit. This problemaggravatedthe feedbacksituationas adjustmentof theSIA volumecor:trolsor a satisfactorysidetone;olumelevelduringSWS ICOMfunctionswouldresultinfeedbackdurinqSWS-initiatedtransmitfunctions.Conversely,satisfactoryolumeleveladjustmentdurinqtransmitfunctionswould resultin low sidetonevolumelevclsduringICOMfunctions.This variationin sidetonelevelpromptedadditionalevaluatiGnoffeedbackoreventionwhich resultedin a requirementto fabricateananti-feedbacknetworkcommunicationassemblywhichwouldreducetheS!,JSicrophonelineqainand reducetheCSM/SWSearphcnelinesi.r_nalleveldurinainitiationof SNS transmitfunctions. Thisassemblywas fabricatedby RockwellInternational,s thedevicewas to matea CSM CCU disconnect.The flightassemblywas deliveredto MDAC-Efor compatibilitytestinqwith the STU/STDNand finaladjustmentofthe loadvalues. This unitsucc__sfullycomple+.edmechanicalandelectricalcompatibilitytest. Themlcrophonelineloadwasadjustedto reducethe SWSmicroph,._Pircuitaudio_ignalsby afactorof II dB and the earphoneline Ioadwas adjustedto reducethe earphonesidetonelevelby a factorof 6 dB durinaSWS initiationof a transmitfunction After the adjustment the unit successfully ,demonstratedthe abilityto _reventacousticalfeedbackwhen theSIA volumecontrolswere not increasedareaterthan II o'clock. Inaddition,theuolinkS-bandreceivedvoicevolumelevelwasimprovedas the STA volumecontrolscouldbe operatedhigherthanbefore At the completionof this testing the unitwas deliveredto KSC for SL-4 stowanein nlaceof the MDAC-Evariablemicroohone

r. , line!cad.

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(2) The Skvlab audio subsystem was reactivated on SL-4 on DOY 321 atapproximately 17:00 GFff. The subsvstem ooeration after activationwas nominal: however, acoustical feedbackwas occasionally noteddurinq crew transmissions,

On DqY 323 the qround controllers in.tiated a crew alert to verifythe C&W and audio subsystem interface ooerational status. The_varninqtone performed as expected; however, an attempt was made toinitiatevoice communicationsdurin_ the crew alert warning tonenresence. This mode of oDeration resulted in very weak intercomvoice transmissions. The mission controllerswere advised thatvoice transmissionsdurin_ a crew alert would be very weak asDreviousivexnerienceddurinn KSC testing. Downlink voice trans-missionswere not affected durino this mode. MDAC-E recommendedthat veice communicationsnot be attempted until after the C&W sub-system master alarm had been reset.

qn DnV 3?8 the crew installed the anti-feedback cnmmu:.ication net-work assembly. The crew reported that the unit was ooeratioqsatisfactorily a_d :,;as Dreventinq acoustical feedback as lon,1 asthe SIA volume controls were kent at a reasonable level.On DgY 333 the crew reported that the SIA located at station 131develooed a malfunction. Crew troubleshootingdetermined thenroblem to be isolated within the microDhol;echannel circuitry asthe u;,itwould receive but would not initiate voic_ communications.The crew succ,_ssfullv r_olaced the defective unit on _v 334 with

_ an onboard snare.

_ qn Do'.' OI_, the cry',,, ;"e,_orted a 6 Hz n,_ise on the Ch._nne! B earphoneline audio. This nois_ was not nre_ent on real-time downlink nor

r on Channel A. Trouhleshontinn reveal_d that the CSMaudio configu-' ratior,had no effect on the r,oblem_ however_ noeninn the Audio

Buffer Amos _I Circuit Breaker caused the noise to cease and itwould nraduallv build up when the breaker was closed, These symptoms

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indicated that the oroblem oriqinated in the Channel B ALC secondaryearphone line amolifier. Analysis i_lthe STU/STDN of a VTR dumptape containinq both Channel A and Channel B audio confirmed thatdiaqnosis and also that t}_eChannel B audio was about 6 dB belowChanne| A and remained at the same level whether or not the AudioBuffer Amps _l broaker was closed. As a result of this oroblem,the crew elected to install the emerqency/taperecorder voice cable,rovided as SL-4 stowane. This cable reolaced a tape recorder "Y"cable a_d was connected between a taoe recoreer and an SIACCUconnector Via a liqhtweightCCU, and provided audio input to thetane recorder directly from the SWS microDhone line. The cable wasinstalled on DOY 30 on tape recorder #l, but subsequent voice dumpswere of oeor quality because the audio level was too low, and thecable was removed_n DnY 32. The reduction in overall gain to the"taoe recorderwhen usinq the cable required a higher audio levelfrom crew voices than _ur the normal configuration. It is believedthat the crew did not provide a hiqh enough voice level, althouqhthey were informedof this requirement.

2.10.I.5 Conclusions and RecommendationsA. Conclusions - The Skylab audio subsystem successfullyprovided inter-

communications,air to qround communicationsand voice tape recordingfunctions throuahout the SL-2, 3 and 4 missions. There were instancesin which the subsystem incurred a definite malfunction. All but one ofthese malfunctionswere corrected or compensated for durinq flight byinfliaht replacement of Failed components or by reconfigurationof theaudio subsystem. The last audio system oroblem, which could not becompletely corrected did not siqnificantly degrade performance, and waspartially comoensatedfo;_ by workaround _rocedures.

An _',ditionalproblem which occurred hut had been orefliqht identifiedas a ootential problem was acoustical feedback occurring during operation

_ from certain SIA locations. This feedback did not hinder communications;howover, it ..lid ca:Jse miror a_c,ra,,ation to the crews. This

_ feedback problem was alleviated with the use of the anti-feedbacki communicationnetwork which was fabricated for the SL-4 mission.,_ 2.10-21


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B. Recommendations - Future manned space programs involving the use ofloud speaker transducers in a voice intercommunication subsystem mustinclude the necessary des-fgn and testing to oreclude the possibilityof acoustical feedback from occurrinQ durin 9 operation in the flightenvironment. The recommendedtechniques which could_be implemented areas fol lows:(1) Limited use of loud speakers and/or compartment acoustical

i solation between communication s rations.(2) Battery operated wireless microphones which include low sensi-

tivity microphones and are retained on the crewman person andheld in c!ose proximity to the voice source (NI to 4 inches).These devices should include individual transmission frequenciesfor each crewman.

Hearing aids should be considered for crewmen utilizationduring habitatlon of low pressure environments. These deviceswill compensate for the drop in acoustical efficiency of theatnw)sphericnedium and in ef allow loud speakervolumes to be reduced to a lower level and enable some voiceconversations to take place without the aid of ;ntercomsystems.

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+ 2.10.2 Data Transmission and Antenna Subsystem

2.10.2.1 Data Transmission and Antenna Subs_st.emDesi9n RequirementsA. Data TransmissionSubsystem- The data transmissionsubsystemwas required

to provide RF transmission capability to the STDN during pre-launch,

! launch, and orbital phases of tne Skylab mission. The transmissionsystem modulation was to be comprised of real tlme PCM and delayed timePCM.B. Antenna Subsystem - An antenna subsystem was required to provide forreception and transmissionof RF signals to and from the STON.

2.10.2.2 Data Transmission and Antenna Subsystem DescriptionThe following paragraphs present the evolution of design changes to the data

transmissionand antenna subsystem, equipment characteristics and configuratiort_ of the final flight subsystem utilized on Skylab I. The flight subsystem was

configured as shown in Figure 2.1025,

. TELEMETRY STUB--_i_ TRANSMrlER /F- D)SCONE LAUNCH

I 2304MHz /_ ANTEN]AS_._ _

TELEMETRY 7 _TRANSMITTER COAX

REALTIMEANDRECORDED 2304Mltz ] SWITCHPCMDATA,RECORDED COAX _

+ VOtCE,NDEMERGENCY _ ]0WATTB SWITCH t !VOICE TELEMETRY COAXTRANSMITTER SWITCH" 246.3kliz

QUADRIPLEXERTELEMETRY JTRANSMI'rI'ER HYBRID COAX R+..omz Ring SmTCHFOMws UMBILICAL

RINGTODCSRECEIVER/DECODERS

FIGURE2.10-5 AIRLOCKDATATRANSMISSIONNDANTENNASYSTEM2 I0 23


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A. Data Transmission Subsystem- The data transmission subsystem requiredtwo major changesto arrive at the final flight configuration. Thesechangeswere requiredto complywith programrequirement_shat expandedas the needsof the Skylabvehiclewerebetteridentified.(1) The initialconfiguratior,ws comprisedof two (2} 2-wattGemini

typefrequency-modulatedelemetrytransmitters.One transmitteroperatingon 230.4MHzwould providerealtimePCM transmissions.The second transmitter operated on a frequency of 246.3 M_iZandprovideddelayed.'timeCM transmissions.Modulationswitchir.gcontrolledmanuallyor by the DCS wouldpermiteithertransmitterto be selectedfor each typeof data transmission.

(2) The firstmajor changeimplementedto the data transmissionsystemaddeda thirdtelemetrytransmitterto enablerecordedvoicedatato be dumpedto the STDN simultaneouslyith the transmissionofreal timePCM and delayedtimePCM. The incorpor_tio'nf a thirdtelemetrytransmitteroccurredconcurrentlyitl,__ deletionofthe voicesubsystemVHF transceiverstherebymakingavailableaquadriplexerchannel. The initialconceptfor the thirdtrans-mitteruseda retunedGemini2-wattunit;however,tradeoffsbetweentransmitteravailabilltyversusgroundstationsignal-to-

" noiseratiorequirementsustifiedincorporationf a lO-watttransmitter.

(3) The secondmajorchangeto the data transmissionsubsystemcon-figurationresultedfromthe datamodulationbandwidthrequirementbeingexpandedto a pointwhere2-watttransmitterswouldnotpr_.ucea satisfactorysignalto noise ratioat the STDN. AMDAC-Estudywas conductedwhichdeterminedthat lO-watttrans-mitterswouldprovidethe neededtransmittedDower. The unitschosenwere existingdesiqnand qualifiedfrequencymodulated ..telemetrytransmitterspreviouslyflo_vnon the Apollo proqramblock I boosters.(4) The finalfliohtconfigurationutilizedthree(3) lO-watttrans-mittersand one (1) 2-watttransmitter.The 2-watttransmitterwas requiredto providerealtime telemetrytransmissionsduringthe launchohaseof the missionas the lO-wattunitswouldcause

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All#LOCK MODULE FINAL TECHNICAL REPORT MDC E0899 VOLUME II -+"

corona within the antenna subsystemquadrtplexer when the vehicletrajectory passed through the altitude regions conducive to

-- orona. Aftervehicleorbitalinsertion,the launch2-watttrans-mitterwas to be deactivatedand the threelO-wattunitsactivated.Modulationswitchinq,controled eithermanually or by groundcommand,oermittedanyof the-datasourcesto be transmlttedandprovidedthe capabilityto transmitthreedatasourcessimultaneously.The lO-watttransmittersthatwere flownwereversionsof the unitsthatwere initiallyprocuredand modifiedto utilizehigh reliabilityscreenedpartsand incorporatea VHF isolator.

TelemetryTransmitter Characteristis:.. TelemetryTransmitter2-Watt - The Airlock"A" 2-watttransmitter was frequency_modulated and operated on a

centerfrequencyof230.4MHz. Itwas utilizedtoproviderealtimetransmissionto the STDNduringthelaunchphaseof SL-I,servingas a backuptransmitterduringthe orbitalphaseof themissfon. The transmitteroutputpowerwas attenuatedby a 2.8 dB lossycoaxialcableto preventcoronafrom occurringwithinthequadriplexerduringascent. The transmitterhad thefolIowlng characteritics:

InputPower 20.5wattsmaximumOutputPower 2.0wattsminimum,2.6wattsnomlnalFrequencyStability +0.01%of.assignedafter

., )'0 second warmupModulationSensitivity IV +l dB peak for lO0 KHzpea]TdeviationLocation ElectronicsModuleNo. 2 "

, ..

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m TelemetryTransmitterlO-WaLt- The AirlocklO-watttrans-mitterswere frequencymodulatedand designatedas "A","B",and "C". The "A"centerfrequencywas 230.4MHz, _the "B" center,requencywas 246.3 MHz and the "C" centerfrequencywas 235.0MHz. Transmittersinputmodulationswitchingwas controlledeithermanuallyor by groundcommand permlttedtransmissionof eitherrealtime ordelayedtimedataand voice to the STDN. The transmitterhad the followingcharacteristics:

InputPower 80watts maximumOutputPower IOwattsminimum,15 wattsmaximumFrequencyStability +0.01%of assignedafter=3"0econdwarmuD,Modulation Sensitivi:ty IV +__!B peak for lO0 VHzpeak deviation

: Location ElectronicsModuleNo. 2B. AntennaSubsystem- The antennasubsystemrequiredthreemajorchanges

to arriveat the finalflightconfiguration.Thesechangeswere requirto complywithprogramrequirementsthatexpandedps the needsof theSkylabvehiclewere betteridentified.(1) The initialantennasubsystemconfigurationas comprisedoftwo GeminiVHFwhip antennas,one GeminiUHFnose stub antenna,

one Gemin_quadriplexermodifiedto accommodatea new +ransmitterfrequency,one Geminidiplexerretunedto accommodatea new voicereceiverfrequency,and one GeminiRF coaxialswitch. The antennasubsystemprovidedthe capabilityfor receptionof450 MHz commandtransmissions,eceptionof 259.7MHz voicetransmis._ions,ndtransmissionof 296.8MHz voiceand 230.4,246.3MHz telemetry.The modifiedGeminiquadriplexerpermittedtransmissionand/orreceptionof fourseparateRF.signalsfromeitherthe launch/orbitalor orbitalantenna. The retunedGeminidiplexerpermittethe receptionof two separateRF signalsfrom the receiveantennaThe coaxialswitchprovideda means to permitootimumselectionbet_Weenhe launch/orbitalnd orbitalantennas,

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(2) The firstmajor changeimplementedto the antennasubsystemaddedtwo disconeantennasmountedon 30 footextendiblebooms,aparasiticantennasubsystemconsistingof a GeminiUHF nose stuband a modifiedGeminiVHF descentantenna,a secondcoaxialswitchand two DCS hybridrings. The disconeantennaswere neededtoprovideadequateantenna.coverages the originalwhip antennacoveragewas.degradedby the incorporationf solararrays. Afterorbitalinsertion,the disconeantennaswere extendedon booms tominimizeshadowingeffectsfrom the solar arrays. The originalcoaxialswitchwas used to selectthe optimumof the two discones.The originalwhip antennaswere to be locatedon the aft SLApanels. Oneof the whip antennaswas to providetelemetrytrans-missionand commandreceptiondurin_ launch,and backupfor thedisconesduringorbitalphases;the secondwhip antennawas toprovidecommandreceptionduringlaunch,and receptio,_f commandand voiceduringorbitalphases. The parasiticantennaswere toconsistof a modifiedGeminiUHFnose stubantennalocatedon theexternalportionof the AM structuraltransitionsection,and a

, modifiedGeminiVHF descentantennalocatedin the EVA lock compart-ment. This antennaconfigurationouldenablepre-EVAcheckoutof the crewmenportablelifesupportsystem(PLSS)RF communications.Concurrentwith this revisionto the antennasubsystem,an additionalDCS receiver/decoderas added to provideredundancy.This DCSadditionrequireda methodto couplethe quadriplexercommandchanneloutputand the diplexercor,_andhanneloutputto the fourDCS receivers.Two coaxialhybridringswere incorporatedintothe antennasystemto satisfythe DCS receiversantennacouplingrequirements.The additionof the secondcoaxialswitchenabledthequadriplexerantennaport to be selectedbetweenthe disconeantennasor the launchwhip.\

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LaunchStub - The launch stub antennawas mountedon theFAS undera protectivefairingand wa; utilizedfortelemetrytransmissionand commandreceptionduringthevehiclelaunchphaseof the mission. Duringthe orbitalphaseof the missionthe antennaservedas a backuptothe disconeantennasystemfor telemetrytransmissionsand commandreception.Duringlaunch,the antenna,a I/4wavelengthmonopoleradiator,provideda gainof O dB or betterwhen referencedto an isotropic,radiatorover 44% Of a spherefor telemetrytransmissions,nd againof -14 dB or betterover83% of a spherefor commandreception.During phaseof the mission,he orbital itprovideda gainof -5 dB or betterover 58% of a sphere"fortelemetrytransmissions,

e CommandStub - The commandstub antennaw_s lo_atedon the, Fixe_AirlockShroudundera protectivefairing,and was

utilizedfor commandreceptionduringthe vehiclelaunchand orbitalphasesnf themission. The antenna,also a

I/4wavelengthmonopoleradiator,provideda gainof -14 dBr better,wi_enreferencedto an isotropicradiatorover83% of a sphere,duringlaunchand -14 dB gainor betterover 88% of a spherein orbit,

DisconeAntennas- Two disconeantennaswer_ installedonantennaboomserectedafterpayloadshroudjettison,andwere configuredso thatradiationcoverageof one antennawas 90 (degrees),lithrespectto the other. Eachwas abi-conicalradiatorconsistingof a lOHnch diameterdiscmountedand insulatedfrom the apexof a coneassembly.The conewas approximatelyI/4wavelengthat its widestpoint and approximatelyI/4wavelengthlong,referencedto its lowestoperatingfrequencyof 230MHz. Theseantennaswere the radiatingelementsfor telemetry

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transmissionand command reception during the orbitalphase. The STDN operators could select the proper disconeantenna by ground command to optimize coverage. Thediscone antenna provided a gain of-5 dB or better whenreferenced to an isotropic radiator over 70?;of a spherefor the telemetry transmission frequencies and -14 dB gainor better over 969;of a sphere for the command receptionfrequency. STDN selection of the optimum discone antennavia the command system resulted in an antenna gain of -5 dB

, or better over 85% of a sphere for the telemetry frequencies,. and -14 dB or better over 97% of a sphere for the command

reception frequency. DCS Hybrid Ring - The AM hybrid coaxial ring assembly

permitted two DCS receivers to be operated from one antenna,and consisted of a l I/2 wavelength section of coaxial :cable connected in a loop configuration. One half (3/4wavelength) of the loop was tapped in four places withcoaxial tee connectors sDaced I/4 wavelength apart. Oneport was connected to the antenna. The two ports that wereone half wavelength apart were connected to the receivers.The remaining purt was terminated with a 50 ohm load. Thisdevice had an insertion loss of 3 dB from the antenna toany one receiver_-and maintained an isolation of at least20 dB between the receivers. The antenna subsystem utilizedtwo hybrid ring assemblies to enable the 4 DCS receivers tobe connected to two antennas.

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i 2.10.2.3 DataTransmissionand AntennaSubsystemTest Results_ The data transmitters,oaxialswitches,and quadriplexerfollowedthe_ normaltest flow: vendorATP,benchlevelPIA,electronicsmodule,then the_ vehiclesystemslevelat both MDAC-Eand KSC. Referto Figure2.10-2and 2.10-3

for MDAC-Eand KSC vehicle-systems-levelest flow. Detailedcomponentand_ moduleleveltestswere emphasizedon the antennasas the reflectiveenvironment_ was not conduciveto RF free-spacetests. The disconeboom rotaryjointswould

notwithstandone "G"vehicledeployment;therefore,disconeantennaandboom_ coaxialsegmentswere VSWRmonitoredduringtestingperformedon a specially_ designedfixturewhichwouldsupportboom deploymentin aone-g environment.I VSWR testsof thedisconeantennaassent)liesere made in a nearlyreflection-i freeenvironmenton a ti_er-tower. Satisfactorytestingof the launchstubi and commandstubwas accomplishedon the FAS module. RF compatibilitytestsi usingflightantennaprototypesweresuccessfullyperformedduringsimulated!i flighttests. CoaxialcableVSWR andinsertionlossmeasurementswere made at_ moduleand totalvehiclelevels.,_ A. ComponentTesting- The significantproblemsexperiercedduringMDAC-E c._mponentestingare discussedbelow. Thosecomponentsnot discussed! experiencedno significantproblemsat the componentlevel.

(1) StubAntenna- Duringacceptanceteststhe 450 MHz VSWR of twocantennasdid-notmeetthe "not-more-than:1"specification.The ca_'seas tracedto improperantennaasse_ly and wascorrected,

(2) 10-_#attM Transmitter- DurinnP!A of S/_I100,a randomfailureof one transistorandtwo resistorscausedan increasein inputcurrent. The faultycomponentswere replaced.

(3) 2-WattTH Trans_itter- Randomfailure.PxperienceddurinnPIAtestingincluded: S/N 20 RF power lossdue to a capacitorfailure,and S/N 21 RF powerlossdue _o capacitormetalcontamination,esultingin a short Replacementof failedcomponentsresolvedthe problems.

(4) CoaxialSwitch- Duringpost requalificationibrationtest,port 2 of S/N Ill coaxialswitchindicatedan out ofspecificationinsertionoss. Failureanalysisshowedburned

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RF switching contacts presumably overstressed at MDAC-E duringPIA Power Altitude tests. The power altitude test was deletedfrom the PIA procedure. All flight s_itches incorporatednewRF switching contacts.

B. System Testing -The evaluation and verification of subsystem performancewas accomplished during Electronics Module I_o.2 test, antenna andcoaxial tests and six major vehicle level tests as shown by Figure2.10-2. Significantantenna and data transmission subsystem problemswere:(1) During Electronics Module 2 tests, it was discovered that

defective coaxial cable connectors were being utilized duringthe coaxial cable a;:.sembly.Rework of Airlock U-l cableassembliesand future built assemblieswas accomplished usingX-rays to determine acceptability of coaxial.cable connector

i- fabrication.(2) During systems validation test, the two-watL telemetry trans-

_ mitrer, S/N 21 output RF power, when measured on the antennaside of the quadriplexer,was 1.74watts _should be not-less-than 2 watts). The fault was isolated to the transmitter,Failure analysis revealed a capacitor had failed due to aminute metal flake which created a resistanceshort causingthe transmitter to be mistuned.

(3) During systems assurance test, the lO-watt transmitters "A" and"C" PCM peak deviation measured 160 KHz and 189 KHz respectively,(should be 87.5 +35 KHz) Excessive noise was Found on-16transmitters "A" and "C" due to a "ringing" between the transmittervoltage regulator and the power iqput in-line filters. Thisresulted in oscillatiunsthat caused the voltage regulator to dropin and out of regulationwith subseque_itfrequencymodulation ofthe carrier. Since the new transmitters had internal filtersinstalled, the separate power ir.putfilters ;vereremoved andflight jumper cables were installed,

(4) During altitude chamber tests, corona of the quadripleker occurredafter an eleven minute period at 150,000 feet while t_singthe two-watt transmitter. Laboratory tests determined that corona in

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residual atmosphere within the 235.0 NIz cavity and resultedin intermittent corona until the quadrip]exer venting wascomplete.

On DOY 158 the STDN reported a loss of signal from the "A"lO-watt transmitter. This loss of signal coincided with thespacecraft atmospheric venting process during EVA preparation.This problem was speculated to have been corona occurringwithinthe quadriplexer. The "A" 2-watt transmitterwas activated andrestoredtelemetry data. Approximately.6hours later the "A"]O-watt transmitterwas reactivatedand provided real timetelemetry transmissions unti] DOY 163.

During DOY 163 the ':A"]O-watt transmitter receiversignals1:rengthindicateda decrease of approximately 12 to 14 dB,in comparisonwith transmitter "B" and "C" receivedsignalstrengths and with transmi;;ter"A" receivedsignal strengthof previous days. This decrease was observed over the Hawaiitrackingstation pass at 163:19:14GMT through 163:19:20.During this period of time, the ;'A"]O-watt transmitterreceived signal varied between -120 dBm to -I06 dBm. For thesame time period, the "B" transmitter receivedsig._alstrengthvariedbetween -102 dBm to -93 dBm. At 163:19:20 GHT the "A"2-watt transmitterwas activated. The receivedsignal throughoutthe 2-watt activation period varied between -114 dBm to -lOl dBm.At 163:19:45GMT over the Vanguard trackingstation the "A"]O-wattand the "A" 2-watt transmitterswere each activated forl minute a?id15 seconds. The received signal strength "indicatedthat the 2-.wattcarrier was approximately3 dB greater than the]O-watt carrier. Durin_ the remainder of DOY 163 and periodicallythroughout DOY 164, the mlssion control]ers continued to cyclebetween the "A" 2-v'attand the "A" ]O-watt transmitters. Each

of these tests indicated that the 2.-watttransmitter was providing

" : approximately2-3 dB greater received signai at the ground stationDuring the.remainder of DOY 163 and through DOY 165 the "B"

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transmitterhad been time shared between real time and delayedtime data. Nn _OY 164, HDAC-E revim_ed [he St. louis STU/STDNRev 428 and 429 data pertaininn to transmitter case temperatures,AM bus currents and received siqnal levels. Evaluation of thisdata revealed that the "A" ]O-wa_t transmittercase temperaturewas siqnificantIvcooler thanTthe other operational transmitters,and that the AM bus current indicated no change, or a decreasein currentwhen the lO-watt transmitterwas selected in p]ace of the2-watt.unit. In addition, the "A" lO-watt case temperaturemeasurements prior to DOY 163 indicated a higher operatingtemperature. These facts coupled with the decrease in receivedsiqna] indicated that the ";'_"O-watt transmitterRF outputDower ha. deeraded siqnificantlv.

_-MDAC-E recommended a transmitter reconfiguration to operatethe "B" transmitter for real time-telemetryuntil a tape dumputil_zinq that frequency was required. At that-time.the realtime telemetry would be temporarilyconfiqured to the "A"2-watt transmitter. This recon=endationwas implemented andcontinued to be utilized throuqh this period.

(2,)_ SL-3 Misslon Results - The "A" 2-watt, and "B" and "C" lO-watt trans-mitters all continued to operate nominally th,'oughout_thisperiod.From DOY 173 through 245, the transmitterconfigurationwas mainitained the same as the latter portion of the SL-2 mission. FromDOY 246 through the end ot the mission, the "B" transmitter wasutilized exclusively for transmissionof real time telemetry andthe "A" 2-watt transmitterwas confiqured for transmission*ofdelayed time voice. Transmitter"C" was _Jtilizedonly for trans-mission of delayed time data.

t"4

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(3) SL-4 Mission Re_Its - The data trapsmissionsubsystem oerformedsatisfactorily throughout the SL-4 Mission, except for the occasionsdiscussed below. The transmitterswere confinured in the samemanner as in the latter portion of the SL-3 mission.

On two occasions, on DOY 335 and on D(_Y353 transmitter "C"failed to respond to DCS commands to power it. These problemseach occurred over a different trackina station and on eachoccasion the oroblem disapoearedwhen transmissionwas attemptedover the next tracking station. A review of telemetry for bothoccasions revealed that the proner DCS co.ands were received.(On one of the occasions, attempt to Dower the transmitterwasmade unsuccessfullyvia two differentDCS commands), Review ofbus current and transmitter temperature indications could notisolate th_ source of the problem. Its cause was speculated tu be

" either temporary contaminationof a relay contact throuqh whichtransmitter "C" power was routed, --ran intermittentmalfunction

.internal to the transmitter.

On DOY 17, no signal was received from Transmitter B at ._r}St_ Carnarvon. Real-ti_m.eelemetrywas s_itched to transmitter C which

provided a siqnal for about lO seconds. Transmitter B wasreselected and it onerated for about 1.5 minutes before aqaindropDin_ off. At Artsat Goldstone, the next station, no siqnal wasreceived from Transmitter B and the A-2-watt transmitterwasselected for real-time telemetry and Drnvidea adequate sianal.Transmitters B and C o_erated satisfactory over the Vanguardstation for a tane dumn and.the normal configurationwas successfullyreestablished; No subsequent problems were noted until DOY 20,when a similar sequence of events occurred. It _,Jasoted that both

, of these occurrences were durinq '1509experiment runs. Examinat.onof cabin Dressure histories indicated pressures high enough to causethe AM cabin oressure relief valves to open. Although the flightolan called for these valves to manually be closed durinq M509

-, runs, the crew stated that the one at panel 3gl (aft compartment)

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AIRLOCK MODULE FINAL TECHNICAL REPORT MDCE0899 VOLUME IIL On DOY176 instrumentationarameterK374whichmonitorsthe2-watt/lO-wattransmittercoaxswitchactivationceasedindicatingthe changefromthe 2-wattto the lO-watttrans-

_ mitter. A reviewof data receivedat the St. LouisSTU/STDN. flcilityrevealedthattilecoaxswitchwas successfullyswitching; betweenthe transmittersand onlythe indicationhad failed,

(3) SL-4 MissionResults- Theperfo'-_ancef all portionsof theantennasubsystemwas consideredcompletelysuccessful during

- the 137-daySL-4mission,exce.otor the two occasionsnotedabove; on DOY 17 and 20, when.thequadrio!exeris believe_to have_- experiencedcorona. The disconeantennaswere againused for_-- telemetrytransmissionand commandreception(withthe command;- stub)exceotfor rareoccasionswhen thelaunchstub antennawasselected. Ootimumantennacoveragewas maintainedby selectinq_ betweendisconesl and 2 approximately6000 times.

2.10,2',5Conclusionsand Recommendations: A. DataTransmissionSubsystem

(1) Conclusions- The data transmissionsubsystemsuccessfully_ providedrealtime PCM,delayedtime PCM,and recordedvoice: transmissitnsthroughoutthe periodfromSL-I launchto SL-4 :

deactivation.The "A" 2-watttransmitterprovidedrealtim,.,telemetrytransmissionsfrom prelaunchthroughorbitalinsertion,The "A" ]O-watt,"B" and "C" transmittersprovidedrealtimePCM, delayedPCM and recordedvoicetransmissionssuccessfully

; , throughoutthe Skylaborbitalmissionswith the exceptionthatthe "A" ]O-watttransmitterdevelopeda malfunctionafter29days of operation. The lossof the "A" lO-watttransmitter

, did not reducethe amountof data transmissioncapabilityas! the "A" 2-watttransmitterwas reactivatedand providedbackup -i capabiIity,

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(2) Recommendations Future space programs requiring the use oftelemetrytransmittersshouldemploysystemswhich will minimizethe n_ber of transmittersrequiredto processmultiplePCM data,A typicalsystemwhich couldbe employedto a_hievethisgoal is_. as fol lows:e Transmittermodulationbandwidthsincreasedby a factorof

I0 overthe existingSkylabunits. Modulationcapabilityto enablesimultaneoustransmissionof

experimenthighbit ratedata via an FM main carrierand lowbit ratehousekeepingdata via a PM modulatedsubcarrier.

o Transmissioncarrierfrequencieshigherthanthe presentV

Documents

MSFC Skylab Airlock Module, Volume 2