Saturn V Launch Vehicle Flight Evaluation Report - AS-510 Apollo 15 Mission

8/7/2019 Saturn V Launch Vehicle Flight Evaluation Report - AS-510 Apollo 15 Mission

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SATURNOCTOBER8,1911

39) SATPBU 5 LAIJIICB II730330 19B~ALOATIOI OBOOBT, AS-510,IOB (MASA) 312 p CSCL 22c Onclas63130 19841\SATURWLAUIICHEHICLEFLIGHT VALUATIOIIEPORT-AS-S10

APOLLO5 MISSlOW

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N.VOb4.L AERONAUTICS .NO SPACE ADMINIST RATION


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MPR-SAT-FE-71-2VEHICLE FLIGHT EVALUATION REPORT - AS-510

APOLLO 15 MISSIONBY

Flight Evaluation Working Group2 C. Marshall Space Flight Center

IABSTRACT

1o 15 Mission) was launched at 9:34:OD EasternComplex 39, Pad A. 1 July 26, 1971, from Kennedy Space Center,"The vehicle lifted off on a launch azisrrth of90 degrees east of north and rolled to a flight azimuth of 80.088 degreeseast of north. The launch vehicle successfully placed the manned space-craft in the planned translunar coast mode. The S-IVB/IU impacted thelunar surface within the planned target area.This was the first Apollo Mission to employ the lunar Roving Vehicle(LRV) during Extravehicular Activity (EVA). The performance of the LRVwas satisfactory and resulted in extended EVA, and greatly increased thecrews lunar exploration capabilities.All Mandatory and Desirable Objectives of this mission for the launchvehicle were accomplished except the precise determination of the lunarimpact point. It is expected that this will be accomplished at a laterdate. No failures, anomalies, or deviations occurred that seriouslyaffected the mission.Any questions or comments Gertaining to the information contained inthis report are invited and should be directed to:

Director, George C. Marshall Space Fltght CenterHuntsville, Alabama 35812Attention: Chairman, Saturn Flight Evaluation WorkingGroup, S&E-CSE-LA (Phone 205-453-2462)


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PRECEDINGAGEBLANKNOT~

TABLE OF CWLNTSLIST OF llllJsTnATlmLIST OF TABLESACK)(OYLEO6EMNTABBREVIATIo)(SNlSSloN PLANFLIW SWIARVNlSSIo)( OO JECT IVES MC(ll9llSHENTFAILURES. RWLIES All0 DEVIATI(wSSECTIOII 1 - lNTRo&JCTlo11.1 Pulplm1.2 SCOPSEC TIOII 2 - EVENT TlllES2.1 Smy of Events2.2 Varlrblc Tim mnd Cm&dSwitch Selector EventsSECT IOII 3 - UINol WEM TImS3.13.23.3:*t 13:4:23.4.33.5i-66 13:6:2

SEcTIan4.1

t-f 1412124.2.3

S-WPmlamch ffllcstonaComtdoun EventsPropellant :ordingW-1 LordlngLOX LoedlngL&f LoeYngS-II InsulrtlonGrand Sloport Eq ulpm tGmawJ/Vehlclr Interface~~fS~lshed6mmd Support

4 - TRUECTORVS-rYTrejectoy EveluetlonAscent PhasePatilng Olbit Phase!rjec)lon Phase4.2.4 Post TL I Phase

TABLE OF CONTENTS

Pa*iii

ViI

xiixlil

rvlrlxXXV

Xxvi

l-ll-1

2-l

2-l

3-6

4-lt::t::4-9

SECT ION 5 - S-It PlDpUlSloll5.1 f-w5.2 s-ic Ignltlen TranslenntPerhmmco5.3 S-IC mslnstage Perfommce5.4 5zlC EnpIne Shutdan TmnslrtPerfomce5.5 S-K ftaga Pnlpallant~tzl66.1 S-IC Fuel Pressurlzatlan 5ystms-IC Pnssurlratlal systm !l5.6.2 S-It LOX Pmssurizatlan 5ystam5.7 S-K PnLmat1c Cmtrol PmsuvB

syS-5.6 s-IC cutge systas5.9 s-xc Pm SLppresslm system5.10 S-IC Hydnullc SystaSECTIOW 6 - S-11 PIDpl,UI(II6.16.2 5-11 ChlllQln md ruil~1rens1entPerf0mcr6.3 s-11 IlrlnsUge hrfom mce6.46.5 s-11 stag Prqmllnt

-t6.66.6.16.6.26.76.86.96.10

5-11 Plrssurlzrtial 5 OI3-11 Fual PI#surlzatan rsystmS-II Lox Pmsurlzatlm sysols-11 Clwlut1c contm1Pressure systm5-11 Ikllu InJectlen 5ys tmW605uvpressla5ystas-11 Hy&ellllc 5ysa

SLCTIOW 7 - s-~n ~lopusIa7.1 S-W7.2 S-IV6 tlrllldam UU Dull*TranslmtClrFoma forFlrat &NW

5-15-Z5-35-6s-6z;5-a5-9

5-105-125-13

6-l6-26-4

6-96-9

Cl0Cl0Cl2Cl6Cl66-16c-16

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7-2

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7.37.4

7.5

7.6

7.7

7.07.97.107.10.17.10.2

7.117.127.137.13.17.13.27.13.37.13.47.13.57.13.67.13.77.14SECTION8.18.28.2.10.2.28.2.38.2.3.18.2.48.3SECTIOK9.19.29.39.3.19.3.29.3.2.19.3.2.29.3.2.39.3.2.49.49.4.19.4.2

TABLE OF CONTENTS (CONTINUED)Page

S-IV8 Mainstage Performancefor First BumS-IVB Shutdown TransientPerformance for First BumS-IVB Parking Orbit CoastPhase ConditioningS-IVB Chilldarn and BuildupTransient Performance forSecond BumS-IV8 Mainstage Performancefor Second BumS-IVB Shutdwn TransientPerformance for Seccmd BumS-IVB Stage PropellantManagementS-IV0 Pressurization Syste mS-IVB Fuel PressurizationSys ternS-IVB LOX Pressurizationsys ternS-IVB Pneuma tic ControlPressure systemS-IVB Auxiliary PropulsionS-IVB Orbital Safing OperationsFuel T ank SafingLOX lank Dueping and SafingCold Helium DunpAmbient Helium DunpStage Pneuma tic Control SphereSafingEngine Start Tank SafingEngine Cmtrol Sphere SafingHydaulic System8 - STRUCTUiESSUl?lldl-jTota l Vehicle StructuresEvaluationLongitudinal LoadsBending HacentsVehicle Dynamic CharacteristicsLongitudinal DynamicCharacteristicsVibrationS-11 POG O Limiting BackupCutoff System9 - GUIDANCE XND NAVIG ATIWSumlayGuidance CoqarisonsNavigation and Guidance SchemeEvaluationNavigation EvaluationGuidax: Schetme EvaluatioaFirst Coo-t PeriodEarth Parking OrbitSecond Boost PeriodPost Tt I PeriodGuidance Syste m ConponentEvaluatiwLVDC and LVJAST-124H Stabi I!red PlatformSubsystem

i-2

7-6

7-7

7-07-127-15

7-157-167-167-18

T-227-277-277-277-297-327-32

7-Y7-327-337-33

a-1

9-l9-1

9-129-129-169-169-169-199-19

9-21g-219-21

SEC'IONID.110.210.310.410;4.110.4.210.4.310.4.4

10.510.6SECTIOn11.111.211.311.411.511.5.111.5.211.6

SECTIDN12.112.217.2.112.2.212.3SECTION1.i.l13.2:.:.313.4

13.5

YCTIDN14.114.214.314.414.4.114.4.2

SECTlOW15.115.2

Page10 - CWTRDL MD SEP ARA TIOIs-v 10-lS-IC Control Sys tm Evaluation 10-ZS-II Control Syste m Evaluation 10-Ss-IVB Control syste mEvaluation 10-7Cmtrol Syste m EvaluationDuring First Bum 10-10Control Syste m EvaluationCuring Parking Orbit lo-10Cmtrol Syste m EvaluationDuring SecondBum lo-13Control Syste m EvaluationAfter S-IVB Second dum 10-16InstMent Ullt Ctmtm lComponents Evaluation lo-26Separation lo-2611 - ELECTRICAL NETUDRKS AMDEIERGENCV DETECTIDK SYSTEMs-v 11-lS-IC Stage Electrical Systcl 11-lS-11 Stage Electrical Sys tm 11-ZS-IV8 Stage Electrical Systa 11-3lnstnnent Wt Electricalsystem 11-3Suay lT-3Battery 6D!O and 6D3D LoadSharing Analysis 11-8Saturn V Emtg ency DetectionSystm (EDS) 11-1412 - VEHICLE PRESSURE ENV IRDMNTS-Y 12-1Base Pressures 12-lS-K Base Pressures 12-1S-II Base Pressures 12-1S-lC/S-II Separation Press~we s 12-l13 - VEHICLE THERMAl ENV!rDm ENTSubnay 13-lS-IC Base Heating 13-1S-11 Base Heating 13-1Vehicle Aeroheating Them alEnvinwncnt 13-6S-IC/S-II Separation ThemalEnvimmnt 13-614 - ENVIROWENTAL CIWRDL SVST'WS-WY 14-1S-IC Enviromntal Control T4-1S-II Envirormental Control 14-3IU Environmcntai Control 14-3Them al Conditioning Syste m 14-3ST-124U-3 Gas Bearingsys- (US) 14-515 - MTA SVSTESs-w 15-1Vehicle Measureme nt Evaluation 15-1


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15.315.3.115.3.215.4

TABLE OF CONTENTS C~NTIN~D)Airborne VHF Tel-trySysem EvaluationPerformance SmtySIC Telemetry tktr LossAfter SeparationC-Band k&r System Evaluation

15.5 Secure Range Sifety CoPmndSystems Evaluation

15.6 Camand and Comumicationsystsn Evaluation15.7 Ground Engineertng CrrrasSECTlOW 16 - MASS CHARACTERISTICS16.1 SUilWl~16.2 Mass EvaluationSECTIOh 1: - LINAR IWACT17.1 Sumnary17.2 Translunar Coast Maneuvers17.3 Trajectory Perturbinginfluences17.4 Trajectory Evaluatlm17.5 lunar Impac t Condftim17.6 Tracking DataSECTTOW 18 - SPACEC RAFT Sv)IARVSECTIO W 19 - A$&D$ ;N$I@ iT

iSEC TIQ I 20 - LINAR ROVING VEHICLE20.1 Smly20.2 Deployment20.3 LRVtoStcwdp~ToadInterfaces2D.4 ;~~~:icability20.5 hhecl-Soil lnte ractfmto.6 Locomotirn Pcrfcmce20.7 khanical Systems20.7.1 Hamanic Drirc23.7.2 hheels tind Srspcnsloe20.7.3 Brakes20.7.4 Suspension nd St&i lity20.7.5 Har.d Controller20.7.6 Loa&20.8 Electrical Systemi5.8.1 Batteries20.8.2 Traction Driwt Systa20.63 Distribution Sg tm20.8.4 Steering20.86 &vp-Hour Integrator20.9 Control and Display Cm soTe29.10 Navigation System20.11 Crew Stattontu.12 ThcrU!20.12.1 sknneiy20.12.2 Transp ortation Phase29;12.3 Ertranhlcular Ac ttvltyPeriods

15-215-215-s15-615-615-615-8

i6-116-1

17-117-217-4

17-1017-1217-13

la-1

19-1

20-l20-l20-Z20-Z20-7

20-1120-17ii-:320117x-1720-1820-MZO-;82D-;8to-i920-19EL::20-7120-2120-2120-2320-2320-2320-23

20.13 Structum20.14 Lmar Roving Vehicleoescriptim20.14.1 LRV Overall Dcscrlpttoa20.14.2 Subsystem Lkscrlptbn20.14.2~1 T4sbility S&system20.14.2.2 Electrical Parr Stisystam20.14.2.3 Control sod Display Console20.14.2.4 Ravigatioo Subsystem20.14.2.5 Crew Station20.14.2.6 Them1 Cmtm l20.14.2.7 Space SIlpport EqulpocntAPPENDIX A - ATlloSpHERLA.1 SunWyA.2 Crneral AtmsphericConditions rt hmch T imA.3 surfxl? mcrvat1ons atLaunch TimA.4 Upper Air Ilcasurea~t~A.4.1 Yind SteedA.4.2A.4.3A-4.4A-4.5A.4.6

i-z 1A:S:ZA.5.3A.5.4A.6

Wind DirectionPitch Wind CaponentYaw Yind CmpmentCorpannt Yfnd ShowsEm ma Mind Data in theHigh Dyomtlc RcglonTherroQnulc DataTcrpcratueAtmospheric Pmsur,Atmospheric Dmslty@tical In&x of NefractlooCogarison of SelectedAtaospherlc Data for Srtum V; l mchs

Plgc20-27M-27ZD-27ET -2%ill::20-WLo-35

A-lA-lA-l;::A-2;::A-4A-4z

A%A-15

A-15APPERDIXE - U-510 SlMTF lCAD T )(IIFIGU MlIOIcJtyltxs8.1 Introdctlm 8-l


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LIST OF ILLUSTRATIUlS

FlguFc2-l4-l

4-2

Page Figure6-6

6-7

6-86-9

6-10

PmJe6-116-136-146-15

Ground Station lime toYehirl: Time CmversimAscent Traje ctory PositionCC#!lpariSOllAscent rrajectury Space-Fixe.Velocity and Flight Psti AngleCarparisonsAscent Traje ctory AcceloratimCmarismOynam ic Pressure and HachNuder CmparismsLaunch Vehicle Ground Trac k

~--I; ,;~1 lank UllagaS-11 Fuel Plunp InletCmdi:imsS-II LOX lank Ullaga PressureS-I: LOX Pmp inletConditlnnsS-:1 CeMer Engine LOXFeeulinn AccwlatorBleea Systcn PerformanceS-11 Cexer Engine LOXFeedline Accuulator Fillbans lent

2-24-2

4-2

4-34-44-8

4-34-4 6-17

6-11

S-II Center Eng!ne LOXFeedline Accuu lator UeliuSupply Systm PerfomanceS-IVB Start 80x and RmRquireRnts - First BumS-IV8 Stea@ StatePerfomance - First RumS-MU5 Perforunco-Coast Phase

4-54-6 B-17Injection Phase Space-FixedVelocity md Flight Path Angle 6-124-9omparisons B-18

7-37-4

1-7

4-7 Injec tion Phase AccelerationCmparismS-:C LOX Start 80x RequimaentsS-IC Engines Thru st BuildupS-IC Stage PrcpulsimPerfomanceNomalized AS-510 OutboardEngine Thrust OecwClbaracterlsticS-It Fuel lank Ullage PressureS-IC LOX Tank Ullage PressureS-K Purge Systcns StorageSphere PRSSURr-l Engine Turbep ~ LOX PurgePressure at Statim 109.Engine No. 1

4-10S-25-3

7-l7-2

7-37-4

5-l5-25-3

S-IVB Ulla* Cmd itimsDurlq RepmsurlutJon'Using 82/H2 BurnerS-Iv8 &/IQ Burner lhrIstand Pmssu rmt Flawa&S-IVB Start Bar and RmRcqulm &s - Second RumS-IVB Engine Turbine InletTeiquratum tcqarlson -First BumS-IVB Engine T urbine InletTclpcm tum Coaparism -SecondBum

5-45-4

5-75-9

5-105-11

7-P7-107-11

5-55-65-75-R

7-57-67-?

5-12

6-37-12

6-l S-11 Engine Sbrt lankPerfomance

6-26-3

6-4

AS-510 CUM Start lank Bech iliPerfornilnce (Engine No. 3)AS-510 COO T Start Tank Pm-cmd ttimfng (Engine No. 3)S-11 Engine Pugr Inlet StartRequl mmnts

6-5 S-11 Steady State Opera tlm

7-87-13

7-147-17

6-5 7-9

7-107-11

S-Iv8 steady StatePerfomance - Secmd BumS-Iv8 Ltl2 UllZge Pm surc -First Bum and ParLtq OrbItS-M Lli2 Ullage Fm ssurr -Second Bum and lrmslmarcast

6-5C66-7 7-w

vi


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Figum?-12

7-137-M

I-157-167-17

I-187-197-20

7-21

8-l

B-2

8-3

a-4

8-S8-68-7

B-8

a-99-1

9-2

9-3

9-4

LIST OF ILLUSTRATItXlS (CONTINUED)S-IV8 Fuel Purp InletConditions - First BumS-Iv9 Fuel Punp InletCondltlms - Second BumS-IV0 LOX Tank Ullage Pmssu re-First Bum and Earth ParkingwitS-IV8 LoI( Plpp InletConditions - First BumC-IV8 13X Pup InletConditions - Sccm d BumS-IW Cold Hellu SupplyHIStOryPncw tic Regulator DischargePmssureS-IV6 LOX Dup andorbitalSafing SequenceS-IW LOX Tm k Ullage PITSSUR.Secmd Bum and TranslunarcoastS-NE LOX aY , Par-wHistorieslongltudlnal Accelw atim atIU and 01 Ow ing Thru st BuildupandLawxhlmgltinal Loed at Tim e ofMa;l~mBendlng tkmnt. CECOkndlng~ntanJNoma~ loadFactor Distributia, at Tlrr ofHaxlnr8cnding mtIU Accelemrter RsponscOwin g Peak 4-5 Hertz Respunse(Longltudlnal)IU nd CM LengltudtnalAcceleration After S-K CEO0IU and M LengltudlnalAcceleration After S-IC OECOAS-HO/AS-509 Acceleration andPressum Osclllatlons bringS-11 Bum (8 to 20 Hz Filter)AS-510 Pig Inlet Pvessura mdThru st Pad AccelerationOscillotlans During AccwlatorFill Transient (1 to 110 HzFilter)S-M Stage Vibration Ennlepeslmjectoy and ST-12W?Platfom Velocity C-risen.Boost-To-W0 (Trejectoy lllnusNWLVOC/21 nsy CWT x Posltlmand Velocity Caparlsans atEFOLVa/Zl Day -1 v PosItIOnend Velocity Coparlsons atEPOlVOC/21 OqV QO T 2 Positionf~a Velocity Colperlsans et

7-19

7-20

7-21

7-237-247-257-26

7-29

7-307-31

a-2

g-3

0-4

U-58-58-6

B-7

0-0a-10

9-2

9-6

FigW9-5

g-69-)-I

9-8g-9

9-109-11

9-129-139-14

10-llo-2

10-3

IO-4

lo-5l&610-llo-8lo-910-15

lo- 11

10-12

10-13

10-14lo-15lo-1610-17

IO-18

LVOC/21 OaylBPTRadlus mCVelocity cceprrisan aL EPOAS-SIG Acceleration and CVSThrust During EPOL&al Ilcasumd Velocitiesat liftoff2 Accelem rrter FloatOeflectlen Befom Liftoff2 Inertial Velocity - ManuelPulse ComtRate-Li=lted PI tch S6nrlngColrnd - AS-510 First BumRate-Li~lted Vr SteeringCound - AS-510 First BumRate-Llalted Pitch SteeringCawed - AS-510 Second B umRate-Lldted V*r SteeringCwman d - AS-510 Second BumST-12411 kcelerater andSym Plckoff OeflectlonsAear LiftoffPitch Plane Dyn.&a DuringS-It Bumvan Plme oynaics lhlrlngS-K Bumz$-Of-Attack lhwlng S-K

~l;;h,tl~ne Dynwlcs Ikrlng

',aw,P:z @n&a OurlqsPitch Plane -a IkrlngS-11 Flnt BumVW Plme @#n&a Ow ingS-IVB Fint EumPitch Plam Dynmlcs DuringParking OrbitPitch Plane Dyn~ics hwlngS-IV6 Second B umV-Plm Bynalcs &wingS-1W Second BumPitch Plnc Gynalcs ckwlnglrmslm ar Coast (Wet 1of 5)AveragePItch ContmlThruster Thrust AfterLox mPltcb. Vrr. md Roll Plmet@IaiCS hWiq Tf3Shlct 1of 2)Saturn V Stagin g MotlanAS-510 Separatim MstanceAS-510 Thrust DecaySIC Lox m Pmsu m andThemal tnvirolmtS-K/S-II Scparetim OlstmceYltb mm? Retrolbton

g-99-10

9-149-149-1s9-17

9-129-20

9-20

g-22

10-310-410-6

10-alo-9

IO-11

10-12lo-1310-MW-15

lo-17

lo-23

10-24IO-27lo-28lo-2810-29lo-29

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Figure11-l

11-ZII-3

11-411-511-Cil-711-e12-I

12-Z12-312-4

13-l13-Z

13-313-4

13-S13-6

13-714-l14-Z

14-314-414-514-6

14-715-l15-215-317-l17-217-317-4

LIST OF ILLUSTl?ATIONS (CONTINUED)S-Ii% Stage rorrard No 1Battery Voltage and CurrentS-IVU Stage Forward No. 2Battery Voltage and CurrentS-IVB Stage Aft No. 1 BatteryVoltage and CurrentS-IV8 Stage Aft No. 2 BatteryVoltage and Current6010 battery MeasurementshD20 Battery Rearurements6030 Battery Measurenents6D4D battery HeasurewntrS-IC Dase Heat ShieldDifferential PressureS-11 Heat Shield FonrrdFace PressureS-11 Thru st Cone PressureS-11 Heat Shield Aft FacePressureS-IC Sase Region Tota lHeating RateS-lr Base Region GasTemwra tureS-IC kbient tas Temp eratureUnder Engine CocoonS-Ii Heat Shield Aft HeatRateS-11 Heat Shield GasRecovery TemperatureS-11 Heat Shield AftRadiation Heat RateForward Location of SeparatedFla on S-IC StageIU TCS Coolant ControlParaznstersIU Sublimator PerfonanceDuring AscentIU TCS Hydrauiic uerfonuanceIll TCS GN2 Sphere PressureSelected IU CanponentTemperaturesIU Inertial Platfon jw2PressurasIU GBS GY 2 Sphere PressureVHF Tellcaety CoverageS-rYC-Band Radar CoverageSumnaryCCS Coverage Sma rylranslunar Coast ManeuversOvervieuDocking and LM EjectionManeuversFirst Lunar Impact TargetinflrbneuversCawarison of Accww latedLw:Jitudina? Velocity Change

Figure17-5

II-411-5

17-6

Ii771-611-7

11-10li-1111-1211-13

17-9li-9

12-t

12-Z12-3

17-102D-129-220-320-420-5

12-3 20-Li3-2

13-2

13-3

20-720-g20-9

13-413-4 29-10

13-513-6

20-11

14-Z

14-414-514-6

20-1220-1320-1414-620-1514-7

14-715-5

15-715-917-517-S

17-717-8

20-1620-17

20-1820-19A-l

A-2

A-3

PdgeReal lime and PostflightLunar Impa ct Points 17-9TCS and APS lhrustPerturbations 17-10Early Track ing Inconsistencyand Passive Thcnnal ControlOscillattons 17-11Lunar Lantirhs of ScientlflcInterest 17-l)Lunar Inpact TargetingConsiderations 17-15Track ing Data Avalldbllity 17-15LRV Traverse s 20-3EVA 1 Slope Distribution 20-5EVA 2 Slope Oistribution 20-5EVA 3 Slope Distribution 20-6SW of EVA's 1, 2 and 3Slope Distribution 20-6Grain Size Distributioncurves from Apollo 15 LunsrSoil Sampler and LSS (YESMix) 20-7LRV Energy Cons-d 29-12Lundr Surface Roughness 20-13MSFC CaputerHodel Lstiu&of Max imm LRV Speed an%lOOth ndi2 LW Range PSOSurface 20-14MSFC Computer Model EstiuWof Maximun LRV Speed onPerfectly Smoo th Surface 20-14MSFC ColputerProgrmEstimate s on LRV YheelSlip Versus Slope AnglelClder Full Throttle(Maxiaura Velocity)Conditions 20-15LRV Battery Temp eraturesfor EVA-l 20-24LRV Battery Tempe raturesfor EVA-2 20-24LRV Battery Tcapcraturesfor EVA-3 20-25LRV Battery TenpcraturesDuring Cooldam 1 20-25LRV Battey TeDperatwesDving Cooldcnm 2 20-26Deployed LRV Yltho ut StaedPayload 20-28Control dnd Display Cms~ le 20-31Deployrrnt Sequence 20-36Surfdce kather !l~ g&worimd tely 1 i/Z HounBefore Launch Jf AS-510 A-2500 Millibar Mdp Approximately1 :/2 kWrS kfOR Ldtdlch OfAS-510 A-3SCadr Wind Speed d t LaunchT'a of AS-510 A-6

viii


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LIST OF ILLUSTRATIDNS (CDNTINCJED)FigurcA 4

A-5h-6A-'

A-0

A .9

Yir.d Dif'ection dt LdmChlime of AS-510 A-7Pitch Wind Velocity Cmpo ner~t(W,) dt Launch TiIdC of AS-510 A-8VM Yind Velocity Ccqonent(W,) dt Ldrnch Tim of AS-510 A-9Pirch (St) dnd Vau (St)ctJllpOlMt Mind Skdl5 dtLdunCh Tlr of AS-510 A-10Reldtiw &VidtiOn ofTclpcrrturr nd Pn!rsu~frcn the PRA-63 ReferenceAtmo sphe m. AS-510 A-13kldtiVe kVidtiCWI Of bSityand &SOlUte kvidtiOII Of theIndex of Refraction fra thePRA-63 Reference Atmosph ere.AS-510 A-14

ix


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ldblc122-l2-22-3

3-l4-l4-z4-34-4

4-55-l5-26-l6-2

z-1

7-2

7-3

?-I7-S8-l9-l

fiiSSil BbJCCtfVCS kCmliShntntSlury of RrirtionsTllr Base 5umwySlgniflcmt Event Tirs SuauryVariable Ti m md Camand 5nltchklcctcr EventsAS-lO/Apollo IS Prtlrubchn11cstawsCorprrison or SlgnlficentTrdjcctory EwcntsConoarisan of Cutoff EnntsColprrison etf kpamtlcin LvcntsPdrkiq Orbit lmcrtloncondl tf alsTrdnslundr lnjcction Cmditlans5-K Inc;tvidual Standard SeaLevel Engine Pcrfoman ccs-IC Propcllrnt n*ss HistoryS-11 Ecglnc Pcrfoman ccAS-510 Flight S-11 PropellantRSS Historys-IVB Stcd4 State Parforaxc -Ftrst Bum STOV +l%SccmdTie Slice at Standard AltitudeCondltians)S-1%510 J-2 Eql~p- Pcrfoman ccAcccptdncc Tes t Tq sS-W6 Stcddy Stdtr Pcrfoman cc -Second Bum (ST UV +lJO-SecondTlr Sllcc at Strndsrd lltltudecaldltioIls)s-IVB strgc PrQlellmt nusHistoryS-IVB APS Pwpcllant ConsugtionPost S-11 CECO 11 tkrtzckcllIrtion~Itwrtdal Plrtfom VclocCtyCapdrlsons (PKSS 12 CoordlndtcSystm)

PH)cXX

XXVI2-32-4

2"1J

3-Z4-54-64-7k-8

4-115-55-B6-6

6-11

l-51-5

7-15T-167-20

a-9

9-3

Tulc9-29-3

9-4

9-5

9-69-79-B10-l

10-210-3lo-4

10-511-l

11-2II-311-411-515-lK-215-315-4

15-5

CtriBnce Caprrlsons (PACSS 13) 9-5St&c icctor Mffcmnca rtTrrrtsluwr InjectIon 9-11First &ad Second Bum TcmlnrlEnd Conditions 9-12Parking Orbit InscrtlonMfferencc srwly (LVOCTclenc tv - Final Trajecto iory)Hawlgrtion *date caqarisons6oost Phase Guidance EventTIRScost Phase 6uidwuc stecrlqComanL at Major EventsHdximcn Con:.,01 Parmetersbring S-lr b'li,phtAS-510 Littiff MiralQJm MtSuRdlylbxlw Control ParrtenOuriq S-11 bumMaxha Cmtrcl ParrctwsOwing S-IVB Fiat BumHdxfau Control ParrrtcnOurtq S-IVI)kcondBum5-K Stage Batb!ry PawComuptiaS-11 Stage Rttory PawConslmQtiaS-IVB Stqc Brttcy ParconslrptionIU Rattmy Pacr CansuptionIU Lord Sharing Carprrison

KG-510 Masumnm t S-yAS-510 FllcJht &rsurcmtsYalvcd Prior to FlightAS-510 NcasumntRlfulctlalsa-510 Latmch W~iclcTel-try Links

9-139-159-189-18

w-5lC-7lo-7

lo-12w-15

11-l11-211-611-911-915-215-315-3

15-4brrnd and CwlcrtlonSyste m Ca;md History. AS-510 15-10

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ACKNOWLEDGEMENT

This report is published by the Saturn Flight Evaluation Working Group,composed of representatives of Marshall Space Flight Center, John F.Kennedy Space Center, and MSFC's prime contractors, and in cooperationwith the Manned Spacecraft Center. Significant contributions to theevaluation have been made by:

George C. Marshall Space Flight CenterScience and Engineering

Ceniral Systems EngineeringAero-Astrodynamics LaboratoryAstrionics LaboratoryComputation LaboratoryAstronautics LaboratorySpace Sciences Laboratory

Program ManagementJohn F. Kennedy Space Center:;anned Spacecraft CenterThe Eoeing CompanyMcDonnell Douglas Astronautics CompanyInternational Business Machines CompanyNorth America11 Rockwell/Space DivisionNorth American Rockwell/Rocketdyne r)ivision

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ABBREVIATIONS

ACNACSALSEPANTAOSADSARIAASCBDABSTC&DCCIFccsCDDTCECOCGCMCNVCR0CRPCSMCT4cvsCYI

Ascension IslandAlternating Current PowerSUPPlYApollo Lunar SurfaceExperiments PackageAntiguaAcquisition of SignalAuxiliary Propulsion SystemApollo Range instrumentAircraftAccelerometer Signal Condi-tionerBermudaBoostControl and Display ConsoleCentral InstrumentationFacilityCommand and Connnunicaticnssys ternCountdown Demonstration TestCenter Engine CutoffCenter of GravityCmand ModuleCape KennedyCarnarvonComputer Reset PulseCommand and Service ModuleCape Telemetry 4Continuous Vert SystemGrand Canary Island

DACDDASDEEDGUDODCMDTSEBWEC0ECPECSEDSEMREMUEPOESCESTETCETWEVAFCCFM/FMFMRFRTGBI

Data Acquisition CameraDigita l Data Acquisitionsys ternDigita l Events EvalcatorDirectional Gyro UnitDesirable ObjectiveData Output MultiplexerData Transmission SystemExploding Bridge WireEngine CutoffEngineering Change ProposalEnvironmental Control SystemEmergency Detection SystemEngine Mixture RatioExtra Vehicular Mobil ityUnitEarth Parking OrbitEngine Start CownnandEastern Standard limeGoddard Experimental TestCenterError Time WordExtra-Vehicular ActivityFlight Control ComputerFrequency Modulation/Frequency ModulationFlight Mission RuleFlight Readiness TestGrand Bahama Island


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GBSGDSGGGOXGRRGSEGSFCGTKGWMHAWHDAHFCVHSKICDIGMIMUIUKSCLCRULETLH2LMLMRLO1LOSLOXLRVLSSLUTLVLVDA

ABBREVIATIOF(S (CONTINUED)Gas Bearing SystemGoldstoneGas GeneratorGaseous OxygenGuidance Reference ReleaseGround Support EquipmentGoddard Space Flight CenterGrand Turk IslandGumHawaiiHolddown ArmHelium Flow Control ValveHoneysuckle CreekInterface Control DocunentIterative Guidance ModeInertial Measurement UnitInstrument UnitKennedy Space CenterLunar Comnunication RelayUnitLaunch Escape TowerLiquid HydrogenLunar ModuleLaunch Mission RuleLunar Orbit InsertionLoss of SignalLiquid OxygenLunar Roving VehicleLunar Soil SimulantLaunch Umbilical TowerLaunch VehicleLaunch Vehicle DataAdapter

LVOCLVGSEMADMAPMCC-HMiLAMLMOMOVMRMRC?MSCMSFCMSFNMSSMTFM/WNPSPNPVNASAOATOCPOECOOFSOOMPTOTPACSSPAFB

Launch Vehicle Digita:ComputerLaunch Vehicle GroundSupport EquipmentMadridMessage Acceptance PulseMission Control Center -HoustonMerritt Island Launch AreaMobile LauncherMandatory ObjectiveMain Oxidizer ValveMixture RatioMixture Ratio Control ValveManned Spacecraft CenterMarshall Space FlightCenterManned Space Flight NetworkMobile Service StructureMississippi Test FacilityMethanol WaterNet Positive SuctionPressureNonpropulsive VentNational Aeronautics andSpace AchiinistrationOverall TestOrbital Correction ProgramOutboard Engine CutoffOverfill Shutoff SensorPostflight TrajectoryOperational TrajectoryProject Apollo CoordinateSystem StandardsPatrick Air Force Base


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MISSION PLAN

The AS-510 flight (Apollo 15 Hission) is the tenth flight in the Apollo/Saturn V flight program, the fifth lunar landing mission, and the thirdlandin ! planned for the lunar highlands. The primary misslon objectivesare: a perform selenological ins ection, survey, and sampling of materialsin the Hadley-Appennine Region; bP deploy and activate the Apollo LunarSurface Experiments Package (ALSEP); c) evaluate-the capability of theApollo equipment to provide extended lunar surface stay time, increasedExtravehicular Activity (EVA), and surface mobility; and d) conductinflight experiments and photographic tasks from lunar orbit. The crewconsists of David R. Scott (Mission Cannander), Alfred M. Uorden, Jr.(Comand Nodule Pilot), and James 9. Irwin (Lunar Mule Pilot).The AS-510 Launch Vehicle (LV) is c-posed of the S-K-10, S-II-IO, andS-IVR-510 stages, and Instrunent Unit (IU)-510. The Spacecraft (SC)consists of SC/Lunar Module Adapter (SLA)-19, Corrnsnd Module (CM)-112,Servjce nodule (SM)-112, and Lunar Module (LM)-10. The UI has beenmodified for this flight and will include the Lunar Roving Vehicle (LBV)-1.Vehicle launch from Complex 39A at Kennedy Space Center (KSC) is alonga 90 degree azimuth with a roll to a flight aziwth of approximately80.088 degrees measured east of true north. Vehicle mass at ignition is6,494,710 ttwn.The S-IC stage powered flight is approximately 159 seconds; the S-II stageprovides powered flight for approxfmately 388 seconds. The S-IVB stagebum of approximately 145 seconds inserts the S-NB/IU/SLA/LU/Camwd andService Module (CSW) into a circular 90 n mS altitude (referenced to theearth equatorial radiusj Earth Parking Omit (EPO). Vehicle mass atorbit insertion is 309,816 llxn.At approximately 10 seconds after EPO insertion, the vehicle is alignedwith the local horizontal. CcuWwus hydrogen venting Ss initiatedshortly after EPO Insertion and the LV and CM systems are checked inpreparation for the Translunar Injection (TLI) bum. During the secondor third'revolution In EPO, the S-IVB stage is restarted and bums forapproxtmately 356 seconds. This bum inserts the S-IVB/IU/SLA/LH/CSM intoa near free-return, translunar trajectory.

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Within 15 minutes after iL1, the vehicle initiates a maneuver to aninertial attitude hold for CSM separation, docking, and LM ejection.Following the attitude freeze, the CSM separates from the LV and the SLApanels are jettisoned. The CSM then transposes and docks to the LM,After docking, the CSMiiM is spring ejected from the S-IVB/IU. Followingseparation of the combined CSM/LM from the S-IVB/IU, the S-IVB/IU willperform a yaw maneuver and then an 80-second burn of the S-IVB AuxiliaryPropulsion System (APS) ullage engines to propel the S-IVB/IU a safedistance away from the spacecraft. Subsequent to the canpletion of theS-IVB/IU evasive maneuver, the S-IVB/IU is placed on a trajectory suchthat it will impact the lunar surface in the vicinity of the Apollo 14landing site. The impact trajector;, is achieved by propulsive ventingof liquid hydrogen (LH2) and dunping of residual liquid oxygen (LOX)and by firing the APS engines. The S-IVB/IU impact will be recordedby t:le seismographs deplo-yed during the Apollo 12 and 14 missions.S-IVB/IU lunar impact is predicted at approximately 79 hours 15 minutesafter launch.Several inflight experiments will be flown on Apollo 15. Several experi-ments are to be conducted by use of the Scientific Instrument Module(SIM) located in Sector I of the SM. A subsatellite is launched fromthe SIM into lunar orbit and several experiments are performed by it.The inflight experiments are conducted during earth orbit, translunarcoast, lunar orbit, and transearth coast mission phases.During the 75-hour 36-minute translunar coast, the astronauts will performstar-earth lanbnark sightings, Inertial Measurement Unit (IW) alignments,general lunar navigation procedures, and possibly four midcourse corrections.At approximately 78 hours and 31 minutes, a Service Propulsion System (SPS),Lunar Orbit Insertion (LOI) bum of approximately 392 seconos is initiatedto insert the CSM/LM into a 58 by 170 n mi altitude parking orbit. Approx-imately two revolutions after LO1 a 22.9-second bum will adjust the orbitinto an 8 by 60 n mi altitude. The L1 is enteed b, astronauts Scott andIrwin, and checkout is accanplished. Buring the twelfth revolution inorbit, at 100.14 hours, the LM separates from the CSM and prepares for thelunar descent. The CSM is then inserted into an approximafely 60 n micircular orbit using a 3.9-second SPS bum. The LM descent propulsionsystem is used to brake the LM into the proper landing trajectory andmaneuver the LM during descent to the lunar surface.Following lunar landing, three EVA time periods of 7, 7, and 6 hours arescheduled during which the astronauts will explore the lunar surface inthe LRV, examine the LM exterior, photograph the lunar surface, and deployscientific instrmnts. Sorties in the LRV will be limited in radiussuch that the life support system capabi'lity will not be exceeded if LRVfailure necessitates the astronauts walking back to the LM. Total staytime on the lunar surface is open-ended. with a planned maxims of 67hours, depending upon the cutcane of current lunar surface operationsplanning and of real-time operational decisions. After the EVA, theastronauts prepare the LM ascent propulsion system for lllnar ascent.

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The CSM performs a plane change approximately 8 hours before rendezvous.At approximately 171-7 hours, the ascent stage inserts the LM into a9 by 46 n mi altitude lunar orbit. At approximately 173.5 hours therendezvous and docking with the CSM are accanplished.Following docking, equipment transfer, and decontamination procedures,the LM ascent stage is jettisoned and targeted to impact the lunar surfaceat a point near the Apollo 15 landing site, but far enough away SO as notto endanger the scientific packages. During the second revolution beforetranseerth injection, the CSM will perform an SPS maneuver to achieve a55 by 75 n mi orbit. Shortly thereafter the subsatellite will be launchedinto the same orbit. Transearth Injection (TEI) is accanplished at theend of revolution 74 at approximately 223 hours and 46 minutes with a!3g-seco;ld SPS burn.During the 71-hour 12-minute transearth coast, the astronauts will performnavigation procedures, star-earth-moon sightings, and possibly threemidcourse corrections. The SM will separate from the CM 15 minutes beforereentry. Splashdown will occur in the Pacific Ocean 295 hours and 12minutes after liftoff.After the recovery operations, a biological quarantine is not imposed onthe crew and CM. However, biological isolation garments will be availablefor use in the event of unexplained crew illness.

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FLIGHT SlMARY

The eighth manned Saturn V Apollo space vehicle, As-510 (Apollo 15 Mission)wa s launched at 9:34:00 Eastern Daylight Tina an July 26, 1971. Theperformance of the launch vehicle was satisfactory ahd at the tlllc ofthis report, all MSFC objectives have been successfully accarplishedexcept for the precise determination of the lunar impact point. Pmlim-inary assessments indicate that the final impact solutlar will satisfythe mission objective.The ground systems supporting the AS-510/Apo110 15 countdam and launchperformed satisfactorily. System canponent failures and mlfunctionsrequiring corrective action were corrected during countdown without causingunscheduled holds. Propellant tanking was accomplished satisfactorily.Damage to the pad, Launch Llabilllcal T-r (LlTT) and support equiprent wasconsidered nrinheal.The vehicle was launched on an anirwrth 90 degrees east of north. A rollmaneuver was initiated at 12.2 seconds that placed the vehicle an a flightazimuth 80.088 degrees east of north. The trajectory parroters fawnlaunch to Translunar Injection (TLI) were close to naninal. Earth ParkingOrbit (EPO) insertion conditions were achieved 4.39 seconds earlier thannominal at a heading angle 0.143 degree less than nainal. TLI was achieved0.88 second later than na9nal. The trsjectory parwaeters at CaRlRlandandService Module (CSH) separation deviated fror nonina since the eventoccurred 94.3 seconds later than predicted.All S-IC propulsion systems performed satisfactorily. In all cases, thepropulsion perfomance was very close to rrminal. Overall stage thrustwas 0.47 percent lower than predicted. Total propellant consuaptton ratewas 0.29 percent 1-r than predicted with the tutal consur0 F!?xL,ure patio(UP) 0.35 percent higher than pm&ted. Spe~iflc impulse was 0.18 percentla#er than predicted. Total propel?mt msuption from Holddoxn Am (HDA)release to Outboard Engine Cutoff iOEC0) was low by 0.03 percent. CenterEngine Cutoff (CECO) was initial by ths Instrtaqnt bit (IU) at136.0 seconds. DECO, lnttiated by LOX low level sensors, occurred at159.56 seconds which was 0.53 second later than predicted, fhe LOX residualat OECO was 31,135 lkp -ared to the predicted 36,115 ltnn. The fuelresidual at OECOwas 27,142 TbA conparedto the predicted 29,404ltnn. TheS-IC experienced a l-1-2-1 start sequence rather than the planned l-2-2sequence. Since engine No. 1 had been repTaced after the sbae static test,It was expected that the planned start seguencewould not be &tained.

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The S-II propulsion system performed satisfactorily throughout flight.The S-II Engine Start Cmand (ESC), as sensed at the engines, occurredat 161.95 seconds. CECO occurred as planned at 459.56 seconds, and OECOoccurred at 549.06 seconds giving an outboard engine operating time of387.11 or 1.16 seconds less than predicted. The eartier than predictedS-II OECO was a result of higher than predicted engine perfomance duringthe low Engine Mixture Ratio (EMR) portion of S-II boost. Four of theeight S-IC retro motors and all of the S-II ullage raoton were rraaovedfor this flight; therefore, the S-IC&II separation sequence wasrevised. This sequence change extended the coast period between S-ICOECO and S-II ESC by on2 second. The WC/S-II separation sequence andS-II engine thrust buildup perfomance was satisfactory. lhe total stagethrust at the standard time slice (61 seconds after S-II ESC) was 0.05percent below predicted. Total propellant flowrate, including pmssur-ization flow, uas 0.03 percent below predictcd and the stage specificimpulse was O.Q2 percent below pmdicted at the standard tille slice.Stage propellant mixture ratio was 0.03 percent above predicted. Enginecutoff transients were normal.This was the second flight stage to incorporate a center engine LOX feedlineaccl:mula?or system as a POGO suppression device. The operation of theaccmq;:?c.tor system was effective in suppressing PC%0 type oscillations.S-II hydraulic system prfomance was nonnal throughout the flight.The S-I@ propulsi~ systea operated satisfactorily throughout opera-tional phase of first and second bums and had normal strrt and cutofftransients. S-IVB first bum tim was 141.5 seconds which was 3.8 sec-onds less than predicted. Approxi~tely 2.6 sacon& of the shorterbum time can be attributed to higher S-IVB perfomnce. The -in&rcan be attributed to S-IC and S-II stage perfor#nces. The engilGa per-formance during first bum, as detemined iron standard altitude rem-struction analysis, deviated frau the predicted S&rtTank Mscharga'Valve (STDV) +130-second tilse slice by 1.82 percent for thrust and:J.09 percent for specific io;pulse. The S-Iv8 stage firstbum EngfneCutoff (ECD) was initiated by the Lauxh Vehicle lMg4ta.l mter (LVDC)at 694.7 seconds. The Continuous Vent Systea (CVS) adequately mgulatedLH tank ullage pmssum at an average level of lg.3 psia during orbt-tan a the Oxygen/Hydrogen (02/t@) burner satisfactorily achieued I.& andLOX tank repressurization for restart EnginemstartcondMens Mumwithin specified lilatts. The restart at full open mixture Ratis CaktmlValve (HRCV) position was successful..Abnormal teuqeratures were not&i in the tsrbine hot gas sysm between firstbum ECD and second burc ESC. kcct noticeable was the fuel turbine inlettemperature. Durirtg LHq chilldown in Tilde Base 6 (T(j), the tarpcratulvdecreased fr,az 130 to -lOoF at second ESC. The oxidizer turbi-nc 9nlett&qeraturc also indicated a small dewwe in tqereture. In rdditIan,fuel turbine inlet tmrature indicated m abnon;llTy fast teqemtum&crease afar first bum ECO. The cause of ti decrease in turbineinlet terqeratum was a snail leak past tAe teflon seal of the gas*newtor fuel valve peppit.


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S-IVB second burn time! was 350.8 seconds which was 5.4 seconds less thanpredicted. The engine ;erformance during second burn, .s determined fromthe standard altitude reconstruction analysis, deviated from the predictedSTDV +130-second time slice by 1.89 percent for thrust and 0.09 percentfor specific impulse. Second bum EC0 was initiated by the LVDC at10,553.7 seconds (02:55:53.7). Subsequent to seconri oum, tile stagepropellant tanks and helium spheres were safed satisfactorily. Sufficientimpulse was derived from LOX dump, LH2 CVS operation and Auxiliary Propul-sion System (APS) ullage bums to achieve a successful lunar impact.The structural loads experienced during the S-IC boost phase were wellbelow design values. The maximum bending moment was 80 x 106 lbf-in. atthe S-IC LOX tank (30 percent of the design value). Thrust cutoff tran-sients experienced by AS-510 were similar to those of previous flights.The maximum longitudinal dynamic responses at the IU were kO.25 g andf0.30 g at S-Ii CECO and OECO, respectively. The magnitudes of the thrustcutoff responses are considered normal. During S-IC stage boost, 4 to5 hertz oscillations were detected beginning at approximately 100 seconds.The maximum amplitude Teasured at the IU was f0.06 g. Oscillations in the4 to 5 hertz range have been observed on previous flights and are consideredto be normal vehicle response to flight environment. POGO did not occurduring S-IC boost. The S-II stage center engjne LOX feedline accumulatorsuccessfully inhibited the 14 to 16 hertz PO@0 oscillations. A peakresponse of kO.6 g was measured on engine No, 5 gimbal pad during steady-state engine operation. As on previous flights, low amplitude 11 hertzoscillations were experienced near the end of S-II burn. Peak engine No. 1gimbal pad response was +O.d6 g. POGO did not oc.ur during S-II boost.The PDGO limiting backup cutoff system performed satisfactorily during theprelaunch and flight operations. The system did not produce any discreteoutputs. The structural loads experienced during the S-IVD stage burnswere well below design values, During first bum the S-!VB experiencedlow amplitude, 16 to 20 hertz oscillations. The amplitudes measured onthe gimbal block were comparable to previous flights and well within theexpected range of values. Similarly, S-IVB second bum produced inter-mittent low amplitude oscillations in the 12 to 16 hertz frequency rangewhich peaked near second burn ECO.The guidance and navigation system provided satisfactory end conditionsfor the boost to Earth Parking Orbit (EPO) and the boost to TLI. knavigation update was performed at the beginning of the second revo'Iut!on,because the differrznce between the ILJ navigation vector and the trackingvector at Camarvon exceeded the allowable tolerance defined in FiightMission Rule (FMR) 7-11. The navigation differences following the up-date were ~~11 and were well witr;n all allowable tolerances at TLI.A negative shift of approximately 0.25 c/s (0.82 ft/s) occurred 'In theZ (down range) accelercmeter output approximately one second before rangezero. The probable cause of the shift has vibration ;rhich h-:13 themeasuring head off null in the negative direction. The preiise effect of

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the shift on subsc?qr;ent nayi. ation errors has not been determined. TheLaunch Vehicle Data Adapter 7 LYDA) and LYDC performed satisfactoiily withnominal values for component temperatures ano paJer supply voltages.The AS-510 control system was diffepnt from that of AS-509 because ofredesigned filters and a revised gain schedule. These changes were madeto stabilize structural dynamics caused by vehicle mass and structuralchanges and to improve wind and engine-out characteristics. The systemperformed satisfactorily. The Flight Control Computer (FCC), Thrust lectorControl (TVC) System, aijd Auxiliary Propulsion System (APS) satisfied allrequirements for vehicle attitude control during the flight. Bending andslosh dynamics were adequately stabil ized. The prelaunch programed yaw,roll, and p< tch Faneuvers were properly executed during S-IC boost. Duringthe maximum dynamic pressure region of flight, the launch vehicle experi-enced winds that were slightly greater than the 95percentile July windfrom a N-degree azimuth. The maximum average pitch engine deflectionwas in the mox.imum dynamic pressure region. The maximum average yaw enginedeflection occurred with the in itial yaw maneuver.S-IC/S-II first and second plane sepsrations were accomplished with nosignificant attituele deviations. The S-IC retro motors performed asexpected. Separation distance was less thhitn predicted because F-l engineimpulse "tailoff" was higher than expected. The effect of the closerS-II exhaust plune at engine start resulted in a more severe environmentat the S-IC forward LOX dome and resulted in S-IC telemetv systemdamage. Analysis indicates that with an S-IC stage having only fourretro motors, failure of one retro motor to ignite would Nsult inmarginal separation distance and in the 3a case, recontact of the twobtages. Consequently, S-IC-11 and subsequent stages will be equippedwith eight r&m motors rather than the planned four.The AS-510 aunch vehicle electrical systems and Emergency Detection System(EDS) perfolmed satisfactorily throughout al l phases of flight. Cperationof the batteries, power supplies, inkrters, Exploding Bridge Wisp (EBW)fir ing units and switch selectors was normal.Vehicle base pressure and base thermal environnhnts, in general, weresimi1.r to those experienced on earlier flights. The envirorunental controlsys%em perfomance was satisfactory.All data systems performed satisfactorily through the flight. Flightmeasurements fran onboard telemetry welo gg.8 percent reliable. Telesnetryperfonance was normal except that the S-IC telemetry WG lost afterS-IC/S-II separation. Radiofreqtincy (fiF) propagation was generally good,though the usual problems due to flame effects and staging were experiencedand an additional dropout occurred when S-II stage flame impinged on theS-IC stage at S-II stage ignition. LZab!e Very High Frequency (VHF) datawere received until 23,225 seconds ;6:27:05). The Secure Range SafetyComiand Systcs (SRSCS) on the S-XC, S- IT, and S-IVB stages tiere ready to

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perform their functions properly, dn crrmand, if flight conditions duringlaunch phase had required destruct. The system properly safed the S-IVBon a cornnand transmitted frail Besn~?a (BDA) at 701.5 seconds. The perfor-mance of the Command and Communications System (ES) was excellent. UsableCCS telemetry data we= received to 48,240 seconds (13:24:00) at which t imethe telmtry subcarrier was inhibited. Ascension (MN), Cailary Islanrl(CYI), Soldstonti (GDS), Hadrid (Y>D), and IYerritt Island Launch A~Pz~ (MILA)were receiving CCS signal carrier .3t S-IYB/IU lunar impact. God trackingdata ore received fron: the C-Band radar. with Carnarvop ;i;RO) indicatingfin&l Lo:s of Signal (LOS) at 53,358 seconds (14:G:18).Al ~spccts of the S-IYl3/1U lunar impact mission objectives were acccm-pi f,hed ruccessfcily with the pclssible exception of the precise determina-tion of theimpact point. Frevisus expei-ience and the high quality andlarge quantity of trircking data indicate that the fina! impact solution.&iii sa?isfy the remaining mission objective after additional analysis.it 285,381.5! seconds (79:24z41:55jn the S-IVBiIU impacted the lunar sur-face at approximately 0.99 degree south latitude and 11.89 degrees westlongitude with a velocity of 2577 m/s (8455 ft/s). This preliminary impactpoint is qproximately 154 kilometers (83 n mi) from the target of 3.67dqrees south lati tude and 7.58 degrees west longitude. The mission objec-tives k!r-re to maneuver the S-ZVS/IU such that it would have at least a50 percent probability of impac,ting the lunar surface with 350 ki Jometers(189 r\ mi) of the target, and tcJ determine the actual impact point within5 kilometers (2.7 n ml), and the time within J second. The AS-510 target-ing philosophy for seismic experiment performance and data resolutiondefined "preferred,'" "acceptable," and "undesirable" impact regions aboutthe Ago110 12 and Apollo 14 lunar seismometers. AJthough the impact Joca-tion is not within the preferred region nor with'in the acceptable regionof .the Apollo 14 seismometer, the principle seismic experiment Investigatorreports that both seismometers gave valuable scientiffc data fmm theimpact. The projected impact paint resulting from the APS-1 maneuver wasperturbed in an easterly direction by unplanned forces acting after theLOX dump. A first force was caused by the ambient heliun pressurizationspheres dumping through the aWent hel ium engine control sphere into theJ-2 ClyiiX!. Other forces were appaently caused by the IU thermal controlsystem water valve operatiens and APS attitude engine reactions. FoJ lowingthe W-2 maneuver, a smali and gradually deceasing unbaJanced force (alsounplanned) acted during I 5-hour period to perturb the lunar impact to aGoint northwest of the target.Al l Lunar Roving Vehicle (LRV) systems performed satisfactorily with therange capability being approximately twi


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ciosure error of less than 0.2 kilometer on each traverse while gym driftwas negligible. The wander factor (LRV path deviation due to obstacles)plus wheel slip was apprcximataly equal to the predicted value of 10percent.The following list of concerns kas recorded curing the lunar surfaceoperation:a. Battery MO. 2 volt-mter was inoperative at first power up.b. Forward steerin was inoperative on Extravehicular Activity (EVA)-1but was successfully activated on EVA-2 and 3.C. Seat belt fastening was excessively time consum?ng.d. Lunar Camnunication Relay Ucit (LCRU) TV dropped out after LM lif toff.e . The left front fender extension was missing after EVA-l.

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MISSION OBJECTIVES ACCOMPLISHMENT

Table 1 presents the MSFC Mandatory Objectives and Desirable Objectivesas defimd in the "Saturn V Apollo 15/AS-510 Mission Implementation Plan,"MSFC Document PM-SAT-8Dl0.8 (Rev. A), dated March 5, 19?1. An assess-ment of the degree of accomplishment of each objective Ts shown. Dis-cucsion supporting the essessmer;t can be found in other sections of thisreport as shown in Table 1.

Table 1. Mission Objectives Accomplishment

1 Launch on a fl!ghtrz luth batman 80 and100 degreec and insert the S-IVB /IU/sc.into tlm lamed clrculrr earth prrkfngarur OVJ .

2I

bstrrt the S-IV8 during rlthr the secondor third revo:utlan md Infect Or S-IWIWKonto the planned trannsluncr tra.jectmy WI).

4 Parfom an rvrrlve yI*ywr 4ttarc l ctio nof the csa/lM fra the s-IuB/IU (DO .5 iqrct the S=:VB/IU on the lunar sffw;ltM; ~Ikll~tmn of lat. 3.65 S, 1~.

6 bromine actual i~ctpointulthin 5kllmtm ud t1P ef IgKttitbinme socmd (00).7 / Aftor find LV/rt seporatfm. vent ncl, Qr3 uu rwlnlng gas and propllati to* safe the s-IvB/IU w.

Eorphb I xone

hplCtrI

xone

s

!

I

PAM6XAPii illUIICH OISUJSSEO4.1. 9.1

4.2.3. 7.6

10.4.4

10.4.4

11.5

17.5

7.13

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FAILURES. ANOPALIES AND DEVIATIONS

Evaluation of the launch vehicle and LRV data revealed seven deviations.There were no fzilures nor anom!ies. The deviations are sumarized inTable 2.Table 2. Sumnary of Deviations1I-I

q

1

-tuuy

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SECTION 1INTRODUCTION

1.; PURPOSEThis report provides the National Aeronautics and Space Administration(NASA) Headquarters, and other interested agencies, with the launchvehicle and Lunar Roving Vehicle (LRV) evaluation results of the AS-510flight (Apollo 15 Mission). The basic objective of flight evaluationis to acquire, reduce, analyze, evaluate and report on flight data tothe extent required to assure future mission success and vehicle reli-ability . To accomplish this objective, actual flight problems areident ified, their causes determined, and recommendations made forappropriate corrective action.1.2 SCOPEThis report contains the performance evaluation of the major launchvehicle systems and LRV, with special emphasis on problems. Swrmariesof launch operations and spacecraft performance are included.The officia l George C. Marshall Space Flight Center (MSFC) position atthis time is represented by this report. It will not be followed by asimilar report unless continued analysis or new information should provethe conclusions presented herein to be signif icantly incorrect. Reportscovering special subjects will be published as required.

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SECTION 2EVENT TIMES

2.1 SUMMARY OF EVENTSRange zero time, the basic time reference for this re rt is 09:34:00Eastern Daylight Time (EDT) (13:34:00 Universal Time UT]) July 26, 1971.Range time is the elapsed tim \? from range zero time and, unless otherwisenoted, is the time used tnroughout this report. All data, except asotherwise defined, presented in "Range Time" are the times at which thedata were received at the telemetry ground station, i.e., actual time ofoccurrence at the vehicle plus telemetry transmission time. The Time-From-Base times are presented as elapsed vehicle time from start of timebase. Vehicle time is the Launch Vehicle Digital Computer (LVDC) clocktime. Figure 2-l shows the conversion between ground station time andvehicle time.Vehicle and ground times for each time base used in the flight sequenceprogram and the signal for initiating each time base are presented inTable 2-l. Start times of TO, Tl, and T2 were nominal. T3, T4, and T5were initiated approximately 0.6 seconds late, 0.6 seconds early and4.4 seconds early, respectively, due to variations in the stage burntimes. These variations are discussed in Sections 5, 6 and 7 of thisdocument. Start times of T6 and T7 were 6.2 seconds late and 0.9 secondlate, respectively. TB, which was initiated by the receipt of a groundcommand, started 66.1 seconds late.A summary of significant events for AS-510 is given in Table 2-2. Thepredicted times for establishing actual minus predicted times inTable 2-2 were taken from 40M336278, "Interface Control DocumentDefinition of Saturn SA-507 and Subs Flight Sequence Program" and fromthe "AS-510 Launch Vehicle Operational Trajectory for July 26, 1971,Laun :h".2.2 VARIABLE TIME AND COMMANDED SWITCH SELECTGR tiiENTSTable 2-3 lists the switch selector events which were issued during theflight, but were not programed for specific times. The water coolantvalve open and close switch selector commands were issued based on thecondition of two thermal switches in the Environmental Control System(ECS). The output of these switches was sampled once every 300 secondsbeginning nominally at 480 seconds, and a switch selector comMnd was

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wciIz

0 5 10 IS 20 25runa WE. 1aoLl SLCORM

, 10 2:oo:oo 4:oo:m 6:00:&l 8:akao

RlllhE Tll . nou6:nlWuTES:SEcm6

Figure 2-1. Ground Station lime to Vehicle Tim Conversion

issued to open or close the water valve. The valve was opened if thetemperature was too high and was closed if the temperature was too low.Data indicate the water coolant valve responded properly to temperaturefluctuations.Table 2-3 also contains the special sequence of switch selector eventswhich were programed to be initiated by telemtry station acquisitionand included the follming calibration sequence:

FUNCTION STAGE TIM (SEC)Telemetry CalibratorInflight Calibrate, ONTM Calibrate, 08TM Calibrate, OFF

IU Acquisition + 60.0

S-IV8 Acquisition + 60.4S-IVB Acquisition + 61.4

Telemetry CalibratorInflight Calibrate, OFF IU Acquisition + 65.0

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Table 2-1. Time Base SumaryVEHICLE TLME GROUND TIMETIME BASE SECONDS SECONDS SIGNAL START(HR:MIN:sEC) (HR:MIN:SEC)

TO -16.94 -16.94 Guidance Reference ReleaseTl 0.58 0.58 IU Umbilical DisconnectSensed by LVDCTZ 136.08 136.08 Down range velocity 2 500 m/Sat Tl +135.5 seconds assensed by LVDCT3 159.58 159.58T4 549.06 549.07T5 694.87 694.88

S-IC OECO Sensed by LVOCS-11 OECO Sensed by LVDCS-IVB EC0 (Velocity)Sensed by LVDC

T6

T7

T8

9624.83 9624.90 Restart Equation Solution(02:40:24.83) (02:40:24.90)10.553.84 10,553.92 S-IVB EC0 (Velocity)(02:55:53.84) (02:55:53.92) Sensed by LVDC16.800.44 16.800.66 Initiated by Ground Comand(04:40:00.44) (04:40:00.66)

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Table 2-2. Significant Event Times SumnaryITEN EVENT OESCRIPrlW

SEC SEC SEC SEC

1 XIDANCE REFERENCE RELEASE -16.9 P.1 -17.s 0.2IGRR)2 S-IC ENGINE ST AR T SEQUENCE -8.9 0.c -9.b 0.1COMMANO IGROUND)3 S-IC EWGIW NO.5 iWART -6.5 r .C -7.1 0.14 S-IC ENGINE NO.3 STA RT -6.3 C.1 -b.9 0.15 S-IC ENGINE NO.2 STA RT -6.3 c.0 -b.O 0.1b S-IC ENGINE NO.6 S TAR T -b. I c.a -b.b 0.27 S-IC ENGINE NO.1 STA RT -6.C 0.C -6.5 0.1U ALL S-It ENGINES THRUS T 01 -1.4 0.1 -2.0 B.29 ANGE ZERO c.0 -C.b

10 ALL HOLDDOWN 4RMS RELEASED 0.3 3.0 -0.3 0.1(FIRST MOTION)

11 IU UMBILICAL OISCONNEC Ir STAR1 0.b -9.1 0.C 0.0OF TIME BASE 1 111)12 BEGIN TOWER CLEARANCE YAW 1.7 0.3 1.1 0.1

MNEUVER13 CNO VAN MANEUVER 9.7 C.@ 9.1 0.114 I)LGIN PITC H AND ROLL R4NEUVER 12.2 Cab 11.6 0.615 S-IC OUTBOARD ENGINE CANT 20.5 4.2 2C.0 0.016 EN0 ROLL MANEUVER 23.0 -0.8 22.* -0.717 MACH 1 b5.C O.b b4.4 U.718 MAXIMUM DVNUlIC PRES SIBE 02.0 1.7 01.4 1.8

(MAX 0)19 S-IC CENTER ENGINE CUT OFF 135.96 -0.1 i 135.38 -6.C 1

(CECOI20 ST AR T OF TIM E BASE 2 (12) 136.1 4.1 c.c C.b21 END PllCH RUIEUVER t:IL7 151.9 1.P 2C.9 1.2

4RRESTb22 S-IC WTBOARD ENGINE CUT OFF 199.56 r.53 23.40 G.b2

(OECO)23 ST AR T OF TIM E BASE 3 (73) 159.6 C.b G.G 0.C

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

EVENT DESCRlPTION

24 Sl4Rl S-11 LH2 TAN K HIGHPRESSURE VEHT MOOE

25IS-II LH2 RECIRCULATION PUMPS

OFF2b S-ICIS -II SEP4R4lION COMMAND

TO FIRE SEPAIATION DEVICESAND RETRO NOTOAS

27 S-II ENGINE STA RT SEQUENCECOMMAND t ESC 1

28 S-II ENGINE SC&EN010 MT IVA T-ION IAVERAGE OF FIVE1

29 S-11 lGNIIION-SlO V OPEN

35

3b

37

3839

4041

42

43-

S-II CHlLlOOYN VALVES CLOSES-I I MAINSTAGES-11 MIW 0.51 EWR NO. 1 ONS-11 HIGH IS.51 EMR NO. 2 ONS-11 SECONO PLANE SEP ARATION

CONMANO 1JElT ISor( S-l I AFTINTEA STliGEtLAUNCH ESCAPE TOWER ILEt

JETTISONITERA TIVE GUIDANCE NOOE 1 IGfi1PHASE I IN1 TIAT EDS-11 CENTER ENGINE CUT OFF

1CECO1STAR T JF 4lTlFICIAL TW MOOES-11 LOU ENGINE MIITU IE RATIO

IEHR1 SWIFT tAClUAL1EN0 OF ARTIFICIAL TAU mQ)ES-II OUTfhOARO ENGINE CUTOFF

1OECO1S-l 1 ENGINE CUTOFF INTERRUPT.START OF TIM OASE 4 IT41

IST LRT OF 101 Pn*SE 31s-IvB ULLAC E rOTOR IGNITIOW

SEC159.7

stc0.b

159.7 c.5

lbl.2 C.5

lb1.9 0.5

162.C O.b

163.0 @.b

164.0 0.5tb4.9 c.5lb?.4 P.5117. b 0.5191.2 9.5

19s.9 -0.5

202. b 2.0

459.Sb 0.52

403.7483.9

-0.11.5

m.2 0.8549. Ob -0.b4

549. I

549.9

4.b

-0.7

P.2

1.7

2.4

2.4

3.4

5.35.41.980 t

31.T

3b. 3

43.0

299.90

SEC0.0

0.0

0.P

0.0

0.0

0.0

0.C0.00.00.00.0

-I*1

1.4

-0.01

-0.b0.9

4.4-1.19

0.0

04

2-5


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Table 2-2. Significant Event Times Sumary (Continued)ITE EVENT DESCRIPTION

-44

4s

464748495051525354555657S859b0bl

b2

63

6465

S-II/S-IVB SEPARATICW CWMANI70 FIRE SEPIRITION DEVICESAND RETRO MOTORSS-IV8 ENGINE ST4Rf CONMIND(FIRST ESC,FUEL CHILLDOWN PUNP OFFS-IVB IGNITION (SfDV OPENIS- I VB HA I NSTAGESTART OF ARTIFICIAL TW WOOES-IVB ULLAGE CASE JETTISONEND OF ARTIFICIAL TAU MWELKGIN T ERNIWI. GUI 04NCEEN0 IGN PIIASE 3BEGIN WI FREELES-IVB VELOCITV CUTOFFCONNRW NO. 1 (FIRST ECOBS-IVB VELOC ITV CUTOFFCOMMAH) NO. 2S-IVfl ENGINE CUTOFF INTERRUPTSTART OF TINE b4SE 5 tT5bS-IvB APS ULL4GE ENGINE NO. 1IGNITION COMMANDS-Iv8 APS ULLAGE ENGINE NO. 2

IGNI T ION COMNANO10x TANK MESSURIZATIW OFFPARKING ORBIT INfERTImBEGIN MANEUVER TO LOCMHORIZWTAL ATT1 TUOE5-1~6 CONTIWWS VENTSVSTEI 1CVSb ON5-1~8 APS ULLAGE ENGINE NO. 1CUTOFF CONM4NO~-1~0 APS ULL4GE ENGINE NO. 2CUTOFF COmANO

550.19i!v7mSEC

-0.bSEC

1.0SE C

0.0

550.2 -0.6 1.1 0.0551.2 -0.7 2.2 0.0553.2 -0.b 4.1 0.0555.7 -0.6 6.6 0.0s57.5 -1.3 0.5 -0. s561.8 -0.7 12.8 0.0

567.0 -1.1 n.9 a.5663.0 -2.6 114.0 -1.9687.8 -4.0 138.7 -3.3b87.8 -4.0 130.7 -3.3694-d -4.40 -0.20 0.00694.79 -0.09 0.01b94.9

-4.39-4.4-4.s-4.s-4.S4*4-3.3-4.4-4.s

-*.s

0.0 0.0695.1 0.3695.2 0.4696.0704.7716.3

1.29.8

21.4753.9781.07e1.9

59.0l 7.007.1

0.00.00.00.01.10.00.00.0

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

88 S-IV8 SECOND IG YI llON ISIDV

b

OPEN)89 -1VB MAINSTAGEqcGINE MIXTURE RAT IO (EMRI

CONTROL VACVF SHIF T (BEGINVALVE MUVtfiENT)

91 S-IVR LHL STFP P4ESS URIZfi.lION(SEC)ND BURN RELAY OFF )

92 Er,lN TERMIN AL GUIDANCE9. BEGIN Ctil FREE ZE94 S-IVB SFCDND GUlOANCt CUT OfF

COMMAND NO. I (SECOND ECJI95 S-IVR SECOND GUIDANCE CU TOF F

COMMAND NO. 2I96 S-IVR tNClNE CU II-IFF INlERRUPl

START OF TIME BASE 797 S-IV6 CVS ON98 TRAYSLUNAR INJECTIUN99 BEGIN ORBITAL NAVIGA TION

1C) BEGIN MANEUVER 10 LflCAlHDRILONIAL AT7lTUDt

101 S-IVH CvS OkF132 HEGIN MANE?IVER TO TRANSPO SI

1lON AND -&CK!NG rrT!Te0FI IDLE I

103 ZS M SEPARAll3N104 csw D(YK105 SC/LV FINAL SEPA RATIO N

100 S TAR T OF TIMi L3ASE tl (181101 S-IVR APS ULLAGE ENGINE NO.

I IGNI 1 ION COMMANO1

-IVR APS ULL AGE ENGINF NO. 2ICNIT ION COMMAND I

SECllil98.C

E TIMEACT-PREDstc

b.2

-A&sSEC

573.1

lC202.9 b.3 578.C C.1

lCL5.413259.4

b.3b.8

5ac.5 a.1b34.5 0.6

10474.9 b.2 85C .c @.I?

IG52b.513 551.5LC553.69

1.9c.71.87

901.5 -4.4926.6 -5.b

-C.23 -0.03

1055 3.79 0.87 -0.12 -c.o2

lC553.9 c.9 C.0 0.c

13554.4IC 563.713 706.0

0.91 .r?

1.9

c.59.1

152.0

0.00.11.0

1T 7Cb. 2 2.1 152.3 1.2

10704. A11454.b

2.9I.7

15c.c9iic.r

0.00.8

12147.2 94.3 1593.3 93.412029.5 176.6 L215.5 175.615481.2 128.3 4927.2 127.4

16BCC. 7 b6.1 0.0 0.01bdOl.a 66.C 1.2 0.0

lbROi.0 66.0 1.4 0.0

l-

2-8


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

-lVR APS ULLACE ENGINE NO. 1CuToFF COMMANDCUTOFF COMMAND

-IVB CVS ON

115 END LOX DUMP116 Ii2 NONPROP ULSIVE VEN T (NPVI ON 18377.7Al? INITIA IE MANEUVER TO AlTITUD E 19c33.5 -16C.9 2832.8 -22b. 9

REJUIRED FOR FINAL S-IV8APS BURN

118 S-IVB APS ULLACE ENCIW NL). 1 2c 760.1 66.3 39bC.0 0.3lGNlllON COMMAND

119 S-IVB APS ULLAGE ENCIW NO. 2 20760.9 66.3 3960.2 0.3IGN IT ION COWAN0

120 S-IVB APS ULLAGE ENC1NE NO. 1 21001.7 13.3 4201.0 7.3CUTO FF CORM AND

121 S-IVB APS ULLACE ENGINE NO. 2 21001.9 73.3 42C 1.2 7.3CUTOFF COMMAND

I22 ZND LUNAR IMPA CT MANWWI COMMAND 35.e6.

I23 S-MAPS IGNllloN )hoDl .

I24 S-W APS IUIDFF #as?.

125 MANLINER TO LOX DUMP AT TITU DE 16.593.

126 0.3 MCRWYCOND ROLL CoMMAllD 3r. I62 .

I27 S-IVBIU LWAR IMPA CT 2Bs.ml.6 a5.B 2w.m.a -5n.5RI2441.0 R4YO.Bl

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

1

1I

1I111I1I1

FIJNCT ION

Yate r Coolant ValveCLOSEDLow (4.8) 04R No. 1Low (4.8) EMR No. 2lelemtry CaiibrdtorInflight Calibrate 3NTM Cailbrate ON

TH Calibrate OFF

Telemetry Cailbrator1n:liyht Calibrate O FFlelemetry Cdlibratcrlnflight Calibrate ONPI Calibrate GN

rH Calibratt OF F

leleme'.ry Calibratorlnflight Calibrate OFFlelemtry Calibratorlnflight Calibrate ONIf4 Calibrate ONft4 Calibrate OFFlelernetrj Calibratorlnflight Calibrate OFF'elemetry Calibrator,nflig ht Calibrate ON'M Caliorate OF F

Telemetry Calibratorlnflight Calibrate ONStart of Time Base 8!lt3)Yater Coolant ValveOPENUater Coolant ValveCLOSEDYater Coolant Va'.OPENYate- Coolant ValveCLOSEDWater Coolant ValveCLOSED

IU 481.4

S-11 483.7S-11 483.9IIJ 1095.8

S-IV8 1096.2

S-IV8 1097.2

IIJ ; 100.7

3191.8

S-:V8 3192.2

S-IV8 3193.2

IIJ 3196.8

IU 5351.8

S-IVB 5352.2S-118 5353.2IU 5356.8

IU 10.773.9

S-IV8 10.775.3

Ill

IU

IU

IU

IU

IU

10.778.9

16.800.7

16.980.7

17.280.7

25.080.7

25.380.8

27.780.7

TI

TIM FRon MSE(SEC)

T) 43L1.8 LVM Function

13 r324.113 l ?24.3T5 two.9

LVDC FunctionLVDC functionAcquisition by CaqaryRevolution 1

I5 l 401.3 Acquisition by CanaryRevolution 115 l 402.3 Acquisition by CanaryC)evolutIon 115 l 4os.g Acquisition by CanaryRevolution 1

T5 42496.9 Acquisition by CamarvorRevolution 1T j +2497.3 Acquisition by CamarvonRevolution 1T5 +2498.3 Acquisition by CamarvonRevolution 1Tr , +2581.9 Acquisition by CarnarvonRevolution 1T5 +4656.9

TS l 4657.3T5 l 4658.3T5 t4661.9

flee,-Ted Data, Goldstone.Texas, WLA. Eemuda

T7 +220.0 Acquisition byHawaii TLI

T7 r221.4 Acquisition byHawaii TLIT, +225.0 Acquisition byHawaii TLI

18 a.0 CCS CommandT8 +180.0 LVDC Function

T8 +480.0 LVDC Function

T8 l 828U.O LWC Function

T8 +8580.1 LVDC Function

T8 +10980.0 LVM runciion

RCMNKS

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SECTION 3LAUNCH OPERATIONS

3.1 SUMMARYThe ground systems supporting the AS-510/Apollo 15 countdown and launchperformed satisfactorily. System component failures and malfunctionsrequir ing corrective action were corrected during countdown withoutcausing unscheduled holds. Propellant tanking was accomplishedsatisfactorily. The space vehicle was launched on schedu,? at 09:34:00Eastern Daylight Time (EDT) on July 26, 1971, from pad 39A of theKennedy Space Center, Saturn Complex. Damage to the pad, LaunchUmbilical Tower (LUT) and s' ,,ort equipment was considered minimal.3.2 PRELAUNCH MILESTONESA chronological summary ,i prelaunch milestones for the AS-510 launchis contained in Table 3-l.3.3 COUNTCCIWN E\;'ENTSThe AS-5lD/Apollo 15 terminal countdown was picked up at T-28 hours onJuly 24, 1971, at 19:OO:OO EDT. Scheduled holds were initia ted atT-9 hours for a duration of 9 hours 34 minutes, and at T-3 hours30 minutes for a duration of 1 hour. Launch occurred on schedule at09:34:00 EDT on July 26, 1971, from pad 39A of the Kennedy Space Center(KSC), Saturn Launch Complex.3.4 PROPELLANT LOADING3.4.1 RP-1 LoadingThe RP-1 system successfully supported countdown and launch withoutincident. Tail Service Mast (TSM) l-2 fi ll and replenish was accom-plished at T-13 hours and S-IC level adjust and fi ll line inert atabout T-l hour. Both operations were completed as planned. Launchcountdown support consumed 212,060 gallons of RP-1.Launch damage was not extensive or serious. The Ansul dry powder fireextinguisher system activated inadvertently in LUT room 4A. The Ansulsystem failure should be evaluated and design corrective action taken ifrequired to prevent problem recurrence. Extensive cleanup was required.

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3.4.3 LH2 LoadingDuring CDDT, the S-IVB LH2 Depletion Sensor No. 1 fai led "wet" after LOXloading and prior to the start of LH2 loading. Investigation disclosedthat the level sensor control unit had been misadjusted during calibrationsuch that its response to input changes was approximately 10 times toogreat. The controller was recalibrated. During inspection, prior tofinal cable reconnection, it was discovered that the unit coaxialconnector teflon insulation had been punctured. The control ler wasremoved and replaced.The LH2 system successfully supported countdown and launch. The fi llsequence began with start of S-II loading at 03:ll:OO EDT, July 26, 1971,and was completed 86 minutes later when al l stage repienish was estab-lished at 04:37:00 EDT. S-II replenish was automatic unti l TerminalCountdown Start (TCDS) at T-187 seconds with one exception at T-3 hours,when both the S-II and S-IVB levels were temporarily controlled in themanual mode to obtain reference data in the event of a PropellantUtilization (PU) system failure. S-IVB replenish was controlledmanually from T-l hour unti l TCDS per the loading procedure. Two minorproblems were encountered with the LUT vent lines; two leak alarms werenoted during fil l and replenish operations; and the S-IVB heat exchangersupply valve failed to open after launch. However, none of theseaffected loading operations. Launch damage was not excessive or serious.Launch countdown support consumed about 470,000 gallons of LH2.3.5 S-II INSULATIONOverall performance of the insulation system on the S-Ii-10 stage wassatisfactory prior to and during launch of the AS-510. No anomalies ofthe insulation system from data readout and visual observation (opera-tional television) were observed. Purge pressures and flows in theforward bulkhead uninsulated area and J ring area were satisfactory.Vacuum in the common bulkhead was recorded as 1.2 psia, well below theredline value of 5 psia.The heat leak to the LH2 was estimated to be approximately 65,000 BTUfor the total mission. This was well within the allowable of209,000 BTU.A limi ted number of defects were noted in the external insulation duringpost-CDDT inspection. The defects included 12 foam divots (occurringprimarily around the feedl ine areas), 3 cork insulation debonds, and15 coating blisters. These defects were repaired within the allottedschedule time.Post-CDDT inspection also revealed defects in the internal spray orablative insulation. These defects were lim ited to approximately 4-squareinch debonded arcas at six locations and hairline cracks located in the

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vicinity of the engine No. 3 area. The ablative insulation wasconsidered acceptable based on structural and heating criteria andno rework was required.All rework if required, however, could have been accomplished within a24-hour turnaround interval.3.6 GROUND SUPPORT EQUIPMENT3.6.1 Ground/Vehicle InterfaceIn general, performance of the ground service systems supporting allstages of the launch vehicle was satisfactory. Overall damage to thepad, LUT, and support equipment from the blast and flame impingementwas considered minimal. Detai led discussion of the Ground SupportEquipment (GSE) is contained in KSC Apollo/Saturn V (AS-510) "GroundSupport Evaluation Report."The S-IVB J-2 engine start tank pressure reached 1400 psia during theplus time operation of Countdown Demonstration Test (CDDT). FlightMission Rule 7-20 was changed from 140G to 1450 psia for the firstopportunity restart pressure lim it in the start tank. The pressureremained below the launch redline and reached 1390 psia prior torestart.The PTCS satisfactorily supported countdown and launch operations.There was no damage or system failures noted. During all-stagereplenish at about T-2 hours 20 minutes, immediately after the S-ICLOX boiloff.test, the tank was replenished to an indicated level of100.16 percent f light mass. The level remained at this value for20 minutes with the replenish valve closed before any noticeablechange was observed. Subsequent operation of the replenish systemwas normal for the remainder of the countdown. A design investigationis recommended.The Data Transmission System (DTS) satisfactorily supported countdownand launch. There were no failures or anomalies and no launch damage.The Environmental Control System (ECS) performed satisfactorilythroughout countdown and launch. Changeover from air to GN2 purgeoccurred at 23:lO:DO EDT, July 25, 1971, 24 minutes before resumingthe count at T-9 hours. GN2 purge was terminated at 09:44:00 EDT,July 26, 1971. One minor problem and one waiver condition wereencountered during countdown operations but did not seriously affectsystem support. During inspection of the chiller solenoid valves atabout T-21 hours, water was found in the connection compartment ofchiller No. 1 valve A6973. The valve was replaced. The cover wasleft off so that if water entered the replacement it could drain offbefore the electrical terminals were shorted. Similar failures of thisvalve occurred on April 21, 1971, and June 23, 1971. Additional failure

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analysis has heen requested. S-IVB aft canparbnent temperature fell belowspecifications for about 1 hour on July 20, 1971 when ECS electrical wireswere disconnected to allow replacement of failed ECS linear power control-ler components. Normal temperature was restored when potter controllerwork was canpleted. A waiver request was prepared by S-IVB engineering tocove;. specification deviation. No adverse effects to the S-IVB were reported.Launch damag s was minor and confined to slightly scorched ducts andsome loose anchor studs on the remote air plenum attached to the ECSroom exterior wall.The Holddown Arms (HDA) and Service Arm Control Switches (SACS) satisfac-torily supported countdown and launch. All HDA released pneumaticallywithin a 3-millisecond period. The retraction and explosive releaselanyard pu ll was accomplished in advance of ordnance actuation with a45-millisecond margin. The pneumatic reiease valves No. 1 and No. 2opened simultaneously 24 milliseconds after the SACS armed signal. TheSACS primary switches closed within 27 milliseconds of each other at449 and 476 milliseconds after comit and the SACS secondary switchesclosed simultaneously 1.112 seconds after commit. Launch damage wasminimal.Overall performance of the Tail Service Masts (TSM) was satisfactory.Mast retraction times were nominal; 2.307 seconds for TSM 1-2,2.151 seconds for TSM 3-2 and 2.688 seconds for TSM 3-4, measured franumbil ical plate separation to mast retracted. There was a minimalamount of heat and blast damage to all masts.At about T-6 hours 25 minutes the TSM 3-2 accumulator pressure meter (M4)indicated approximately 150 psig lower than the alternate monitoringfacilities. This indicated that an end item component in the LaunchControl Center (LCC) Panel had experienced some degradation. Systempressure switch status was monitored as an indication of system readi-ness for the remainder of the countdown. Troubleshooting and correctiveaction were postponed until after launch.The Preflight and Inflight Service Arms (S/A 1 through S/A 8) supportedcountdown satisfactorily. The performance of the Inflight Service Armswas within design parameters during terminal count and liftoff. Onlyexpected minor damage, similar to previous launches, occurred on thelower Pref light Service Arms (S/A 1, 2, and 3). Damage on the InflightService Arms was also minor, with damage judged even less than on previouslaunches.3.6.2 MSFC Furnished Ground Support EquipmentThe S-IC Mechanical GSE performance for countdown and launch was nominal.Launch damage was negligib le and only one minor problem occurred. TheAnsul fire extinguisher activated, apparently due to launch vibrations,blanketing Mobile Launcher Room 4Ab equipment with chemical powder.

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The S-IC electrical GSE satisfactorily supported countdown and launch.No failures or anomalies were noted in any of the electrical GSE systems.Launch damage was minor.Al l ground power and battery equipment satisfactorily supported countdownfrom the start of precount through launch. All systems performed withinacceptable limits. No significant damage occurred to ground power equip-ment during AS-510 launch. A minor problem occurred at T-48 hours whenthe S-IVB flight battery console intermittently printed out erroneousvoltage values and channel numbers. The console was replaced and noproblems were experienced with the replacement.The Hazardous Gas Detection System (HGDS) became active in countdown andlaunch operations at 23:00:00 EDT, July 25, 1971, and maintained satis-factory support through lifto ff with no significant system problems.The system continued to operate satisfactorily after launch and wassecured at 13:30:00 EDT, July 26, 1971. There was no reportable launchdamage to the HGDS or the HGDS sample lines.The S-IC flight control system performed satisfactorily throughout pre-launch checkout and flight. One waivered exception was encountered.At about T-4 hours 30 minutes the No. 3 pitch actuator indicated a gainof 0.352 at switch point 2. Nominal at this point is 0.300 and theupper limit is 0.342. This condition had been anticipated. A waiverrequest dated May 12, 1971, increased the upper limit for No. 3 pitchactuator to 0.362. Because of this prior approval no impact to count-down operations resulted.

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SECTION 4TRAJECTORY

4.1 SUMMARYThe vehicle was launched on an azimuth 90 degrees east of north. A rollmaneuver was initiated at 12.2 seconds that placed the vehicle on aflight azimuth of 80.088 degrees east of north. The reconstructed tra-jectory was generazed by merging the following four trajectory segments:the ascent phac-, parking orbit phase, injection phase, and postTranslunar 1njt;tion (TLI) phase. The analysis for each phase wasconducted separately with appropriate end point constraints to providetrajectory continuity. Available C-Band radar and Unified S-Band (USB)tracking data plus telemetered guidance velocity data were used in thetrajectory reconstruction.The trajectory parameters from launch to TLI were close to nominal.Earth parking orbit insertion conditions were achieved 4.39 secondsearlier than nominal at a heading angle 0.143 degree less than nominal.TLI was achieved 0.88 second later than nominal. The trajectoryparameters at Command and Service Module (CSM) separation deviated fromnominal since the event occurred 94.3 seconds later than predicted.4.2 TRAJECTORY EVALUATION4.2.1 Ascent PhaseThe ascent phase spans the interval from guidance reference releasethrough parking orbit insertion. The ascent trajectory was establishedby using telemetered guidance velocities as generating parameters to fittracking data from five C-Band stations and one Hand station. Approxi-mately 15 percent of the C-Band tracking data and 10 percent of theS-Band tracking data were eliminated due to inconsistencies. The launchphase portion of the ascent phase, (liftoff to approximately 20 seconds),was established by constraining integrated telemetered guidanceaccelerometer data to the best estimate trajectory.Actual and nominal altitude, surface range, and cross range for theirrcent phase are presented in Figure 4-l. Actual and nominal space-fixed velocity and flight path angle during ascent are shown inFigure 4-2. Actual and nominal comparisons of total inertial accelera-tions are shown in Figure 4-3. The maximum acceleration during S-ICburn was 3.97 g.

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RANGE TIRE . SECONDSFigure 4-1. Ascent Trajectory Position Comparison

_---eooo

if!%+

:g/ 1 ,v7000

9000 I- I- ACTUAL I I I

NOMINALs-IC OECOI s-11 OECOS-IV9 FIRST

6000

RAISE TINE , SEcOaoSFigure 4-2. Ascent Trajectory Space-Fixed Velocity and FlightPath Angle Coqwisons

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- ACTUAL---- NOMINAL

35 v S-IC CECOw S-IC OECOv S-11 CECO

30. V EMR SHIFTv S-II OECO

S-*"B FIRST EC0, , ! , , , , v ,

100 200 300 400 500 600 700 BOORANGE TIME, SECONDS

Figure 4-3. Ascent Trajectory Acceleration Comparison

Mach number and dynamic pressure are shown in Figure 4-4. Theseparameters were calculated using meteorological data measured to analtitude of 58.0 kilometers (31.3 n mi). Above this altitude, themeasured data were merged into the U. S. Standard Reference Atmosphere.Actual and nominal values of parameters at significant trajectory eventtimes, cutoff events, and separation events are shown in Tables 4-1,4-2, and 4-3, respectively.4.2.2 Parking Orb-it PhaseOrbital tracking was conducted by the NASA Manned Space Flight Network.Four C-Band stations (Merritt Island, two Bermuda radars and Carnarvon)provided six data passes. Two S-Band stations (Texas and Merritt Island)furnished two additional tracking passes.

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Fi gure 4 -4. Dynamic Pressure and Mach Number Comparisons

/

wl i !i1 I Ia0 !OO II20 IGO 160 1.90IANGL TI*i. SECOMOS

The parking orbit trajectory was obtained by integrating a comprehensiveorbit model with corrected insertion conditions forward to 10,010 seconds(2:46:50). The final insertion conditions were obtained through adifferential correction procedure in the Orbital Correction Program (OCP)which adjusted the preliminary estimate of insertion conditions to finalvalues in accordance with relative weights assigned to the tracking data.The orbital acceleration model was derived from telemetered guidancevelocity data generated by the ST-124M-3 guidance platform.A comparison of actual and nominal parking orbit insertion parameters ispresented in Table 4-4. The ground track from insertion to S-IVB/CSMseparation is given in Figure 4-5.4.2.3 Injection PhaseThe injection phase was generated by the integration of the telemeteredguidance accelerometer data. These accelerometer data were initializedfrom a parking orbit state vector at 10,010 seconds (02:46:50) and wereconstrained to a state vector at TLI obtained from the post TLI tra-jectory. The S-Band tracking data available during the early portion ofthe injection phase were not used in the trajectory reconstructionbecause the data were inconsistent with parking orbit and translunarorbit tracking solutions.Comparisons between the actual and nominal space-fixed velocity andflight path angle are shown in Figure 4-6. The actual and nominaltotal inertial acceleratiobi comparisons are presented in Figure 4-7.

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Table 4-l. Comparison of Significant Trajectory EventsINN1 PAPA*tlfP ACltIAL YCWINAL Ml-NOW

F1r5t *ot1an Pdnqe :*me . rer 0.3 0.3 0.0T,(dl InertrII P:celrratl"n. "3,s 2 IO.61 IO.74 [email protected]) (35 241 (-C.43)(I.OF ) II 10) (-0.02)

NBCk 1 aanqe TV*e .


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Table 4-2. Comparison of Cutoff EventsPARNWt I I acluAl I *O"!""l 1 ACT-MOM ~ClUAl 1 no*l*AL 1 ac:-no*I I 1 I I

S-1: CfCO (tItGlME SOlEMOlD) 5-IC OEC O (t?lGlllt 5OltNOlO)n4nqc TlrnC. *ec 135.96 116.07 -0 II 159.56 159.01 0.53Altltudc. km 46.6 47.3 -0.5 68.4 68.6 -0.2In ml) (25.3) (25.5) I-0.2) 06.9; (37.0) (-0.1)SV4cr-Fl.ed Velocity. 81, 2.044.l 2.061.4 -16.7 2.756.4 2.747.2 9.2

(ft/s) (6.70.3.3 ) (6.76 1.1) (-54.0) (9.043.3) (9.013.1) (30.2:tlfqht P4th bnqlc. deq 21.217 24.401 -0.106 21.266 2:.523 -D.257lleadlnq Anq lc. dcq 82.494 l12.533 -0.039 ez.129 82.215 -0.086Surfacr n4nqe. km 0.1 48.7 -0.6 90.0 89.5 0.5(n ml) (26.0) (26.3) t-0 3) (40.0 r4a.31 (0.3)crorr nrnqc. Lm 0.2 0.2 0.0 0.3 0.4 -0.1

(n =I) (0.1) (0-I) 10.0) (0.2) (0.2) 10.0)CWS Qrnq c VVloclt m/ s

I'3.9 5.6

rt /sj (1z.e) (18.4) ,.A:6.8 10.4 -3.6(22.1) (34.1) (-11.1)- S-11 CCC0 (E11611t SOlEMOlD) S-11 OlCO (fMGllt SOLtH01D)

I4nqc Tlmc. ICC 459.56 459.04 0.52 549.06 549.70 -0.64hltltudr. Lm 178.2 l70.2 0.0 176.3 175.8 0.51. -0 (96.2) (96.2) (0.0) (95.2) (94.9) (0.3)SV4c4-Ftx4d Vcloclty. l ls 5.713.4 5.708.4 5.0 6.995.0 6.915.2 9.8(rt/s ) (la.744.e) (lb.72tl.3) (16.5) (22.949.5) (22.917.3) (32.2)Fl lqht Path Angl4. dqg -0.2q5 -0.352 0.067 0.059 0.025 0.03bHrrdlnq Asq lq. dcg 07.150 67.101 0.049 19.163 89.064 -0.OOllurfrc* hag*. km 1.103.6 1.100.6 3.2 1.619.6 -3.3fn l I) (596.0) (594.3) (1.7) (074.5) ~i! ifj: (-1.0kOS nrnqr. km 16.1 15.6 0.3 29.5 29.1 0.4(n =I) (0.7) (8.5) (9.2l (15.9) (15.7) (0.2)Cross q4n qc v4loc tty.(;m;,) 121.6 118.0 3.6 181.4 179.2099.0) (lS7.1) (11.9) (595.1) (587.9) (7Y

S-IV0 1ST OUID4ICE CUT OFF S16661 S-IVB ZID 6UIOUCE CUTO VF SILlINIrngr Itm e, see 694.67 699.06 -4.39 10.553.61 lD.552.73 0.08hltltudq. km 172.6 171.6 (o!if 307.5 310.6 -3.3(n -0 03.2) l92.e) (166.0) (167.6) (-1.6)ip4cq-Fl1qd Vqloc ~ty. m/ s 7.601.9 7.602.5 -0.6 10.652.9 10.650.6(fl/S) (25.596.6) (25.598.8) (-2.D) (35.6D6.6) (35.599.1) (7:;:'Ilqht D4th Angle. deq 0.013 -0.002 0.015 6.952 7.142 -0.190I44dlnq Lnglr. oeq 95.149 95.293 -0.144 72.782 72.930 -0.148iurrrcr nrng*. km 2.605.4 2.633.6 -26.2In =I) (1.406.0 (1.42:.0) (-15.2):ross nrnqe. km 61.9 62.2 -0.3(n 91) (33.4) (33.6) (-D.21:ross nrng. vqloct ty. (~mj , ) 265.6 266.7 -0.9(672.0) 075.0) t-3.0)Inclln4tlon. do) 29.605 29.696 -0.011ksccndirq lode. dq g 106.419 106.653 -D.D3d:CcqntrlClty 0.9749 0.9750 -O.DDDl:3** .2/ 2(ft j S 2 -1.522.505 -1.514.734(-16.388.107) -7.77:(-16.304.461) (-83.646)

Times used 4r. Vqhlclq tlms.IS trlce the s)oc1fl~ .".r,y of orbtt. v2 _ p

V . Ihqrtl41 Vc*ocIt,Y . Sr4VttitlOn.l conrtrntn l nwlus rector f rom c*nter Of l 4rt)I

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Table 4-3. Comparison of Separation EventsPARAC(flER

5-lC;S-11 SEPA9ATION

Rdnqe Time. le:Altitude. km(n mi)SDace-FIxed Velocity, m/s

tr t /sjFliqht Path Anale, deaHeading Angle. deaSurface Range. km(n ni)Cross Ranae, km(n mi)Cross Range Velocity. mls

(ft/\)Geod ctlc Latitude. dea NLongitud e, lea t

161.2 16RP 0.470.1 ?I' 4 -0.3

(37.9) OR.01 f-0.1)2.162.2 2.153.4 8.8(9.062.3) (9.033.5) (2A.8)

21.021 21 .?Sl -0.231-I82.144 R2.231

93.5(50.5)0.3

(0.2)7.1

(23.312P.748

93.3(50.4)

0.4(0.2)

10.7(35.1)2R.746

-79.663S- I I /S- IVP SiPAF!ATION

-0.087

cofif^-0.1(n.n)-3.6

(-11.R)0.002

-79.661 0.002

Ranae line. *ccAltitude. hm

(n ml)Soace-fired Velocity. mis(ftls)Flight Path Anqle. dcaHeadina Angle. degSurface Ranoe. km(n mi)Cross flange. km(n ml)Cross Ranqe Velocity. m/ s

(ftls)Geode tic Latitude. dea NLongitud e. deo E

550.1 550.H -0.7176.3

(95.2)5.999.022.962.6)

l - ! .OPI

175.8 0.5(94.9) (fl.3)

6.988.7 tn.3(22.928.8) (33.P)n.n15 0.032

R9.9@0 89.901 -0.0011.626.3 1 .629.8 -3.5(H7B.l) (88O.ll) (-1.9)

29.7 29.3 0.4(16.0) (15.8) (0.2)lR2.0(597.1)

29.843-63.922

179.7 2.3(589.6) (7.5)27.847 .n.nob

-63.886 -0.036S-IVBICSM SEPARATION

Rbnqe Time, setAltitude, lw(n ml)Sobce-Fired Velocitv. m/s

(ft/s)Flight Peth Angle. degHerding Angle. dcgtcodetlc lbtitude. dco NLongitude. deg I

12.147.2 12.052.97.459.8 6.97?.7(4.028.0) (3.767.7)7.494.1 7.631.524..586.9) (25.037.1)

46.011 45.046JlZ.b93 111.816

19.957 2n. i24-62.502 -64 048

94.3

482.1(260.3)-137.4

(-450.8)0.96s0.677

-0.7671.546

NO TE: Time s used Ire vehicle t imes.

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I i I- -.~-- -c - .-.- . I

02 49.00 02,jZ:OL 12:ss:ot iRANGE TIHE. HOURS:I~INUTES 2ECONDS

Figure 4-7. Injecti

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Saturn V Launch Vehicle Flight Evaluation Report - AS-510 Apollo 15 Mission

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