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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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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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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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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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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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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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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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FIGURES CONTINUED
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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OF FIGURES CONTINUED
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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FIGURES CONTINUED
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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FIGURESCONTINFD
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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FIGURES CONTINUED
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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FIGURES CONTINUED
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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L_IST_OFFIGURESCONTINUEDi j .
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. ,
2.I0-I
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AIRLOCK MODULE FINAL TECHNICAL REPORT MDCE0899 VOLUMEII
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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AIRLOCK MODULE FINAL TECHNICAL REPORT MDCE0899 VOLUMEII
_ 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.
2.10-3
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AIRLOCK MODULE FINAL TECHNICAL REPORT MDCE0899 VOLUME
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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AIRLOCK MODULE FINAL TECHNICAL REPORT MCCE0899 VOLUM
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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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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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
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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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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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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