Lunar Module / Abort Guidance System (LM/AGS)

97 Pages·05.94 MB·English

1969024052
TRW
' _,SYSTEMSGROUP
PIARK " REEE)NDO BEACH, CALIFORNIA
1969024052-002
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06,114.6008- TO00
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_UNAMRODULE/ABGOURITDANCE
;',_:. -_! _ SYSTE(MLM/AGS)
_' NASA/ERC
;. DesigCnriteriParogram,
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" GuidanacendControl
_,
'.'\4, '
'_it .b _" " 1968 September
-f- ',* Prepared for:
._., i:i ,... • :1# AEelreocntarount;lccss aRnedseSarpcahceCeAndtmerinistrat;on
, .,_. __ Cambridge, Massachusetts
, ' '_ .... Contract NAS 12-110
...:.K.i," _"
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_ SYSTEMS GROUP
LC_ PA_K • ,_[ DONDO 13_A(:_t, (.AI IF(_f.'i_,HA
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1969024052-003
LUNAR MODULE/ABORT GUIDANCE
SYSTEM (LM/AGS)
DESIGN SURVEY
NASA_RC DESIGN CRITERIAPROGRAM
GUPDANCE AND CONTROL
Preparedfor
National AeronauticsandSpaceAdministration
Electronlcs ResearchCenter
Cambridge, Massachusetts
Contract NAS 12-110
1968Sep;._mber
Approved:
N. W. Trembath
LM/AGS ProgramManager
"" Approved:
"_ T. W Layton
,V;': StudyManager
':"_ Contract NAS 12-110
_."
_.,
]969024052-004
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I
I FOREWORD
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I produ_cheids rbeyporitnduisstrioanle ocfonatrascetroiress ofasdepsaigrnt osfurtvheeysNASbAeing
Design Criteria Program. The objective of the Program is
provide approaches
I to a unification of design for the devel-
opment of space vehicles and their major components. The
i sfruormveysspecaifriec inNteAndSeAd prtoojedcotscumeanntd wdilelsigbne uesxepderieanscean aigdainined
, identifying suitable topics for design criteria monographs.
I This report summarizes TRW' s design experience to
date in developing the Lunar Module Abort Guidance System
_ I for the Apollo Program, and relates this experience to the
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NASA/ERC Design Critera Program for Guidance and
Control.
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I The preparation of this report was supervised and coor-
dinated by Dr. T. W. Layton and J. A. Vanderlaan. Major
I sections were prepared by: J, A. Vanderlaan, H. D. Blow,
i
G. M. Petrov, F. A. Evans, W. M. Ashley, P. B. Aubol,
l' Mt,_chLn.icOablrciognhtte,ntanwderDe.JS.arSg.enHti.ll,AHd.diAt.ionIarlwicno,ntLr.ibNu.toJresnokfs,
D. Wede_ ,nd, T. A. Fuhrman, W. W. Benjamin, R. E.
Morse, and H. A. Pudewa.
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III
1969024052-005
i PRECEDING PAGE BLANK NOT FILMED.
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I CONTENTS
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SUMMARY
I i. l
Z. SYSTEM DESCRIPTION Z
J Z. i CZ.OIN.FIIGURAAbToIrOtNSensor Assembly 2Z
Z. i. 2 Abort Electronics Assembly Z
Z. 3 and
I I. Data Entry Display Assembly Z
Z.Z OPERATIONAL CHARACTERISTICS 5
Z2..ZZ.. iZ LMuanjoarr MLMod/AulGeS MFisusinocntions 55
Z.3 PERFORMANCE CHARACTERISTICS 7
8
Z.4 ENVIRONMENTAL CONSIDERATIONS
Z. 4. i Thermal Environment 8
_. 3. HISTORICZA.4L.2 SUMVMibrAaRtioYn OEFnvAirGonSmeDntESIGN DEVELOPMENT i,80o
I; ,O
3. i. 2 Sensor Assembly Concept iO
•_ 3.Z M3..AZJ.OiR DMESoIdGifNicatioCnHsANGECSaused by Changes in Functional ii
Requirements i i
I_. 3. Z. Z MReoqduifiirceamtieonntss Caused by Changes in Mission iZ
3.3 HISTORICAL SUMMARY OF DESIGN DEVELOPMENT
" OF THE ABORT SENSOR ASSEMBLY i3
3.3.'. Early History i3
3.3.2 Design Concepts at Program Start i3
Ii 3.3.3 Outline of Design Evaluation i4
3.3.4 Chronological Outline of Design Changes,
I Problems, and Solutions i4
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1969024052-006
CONTENTS (Continued)
3.4 HISTORICAL SUMMARY OF DESIGN DEVELOPMENT
OF THE COMPUTER SUBSYSTEMS (AEA AND DEDA) 24
3.4.I Early Design Decisions Z4
3.4. Z Design Development History of A_A Subsections 26
3.5 HISTORICAL SUMMARY OF SOFTWARE DESIGN
DEVELOPMENT 29
3.5.i Early History 29
3.5. Z Program Modifications Subsequent to DMCP 30
4. MAJOR DESIGN PROBLEMS _ 33
4.i DISCUSSION OF MAJOR DESIGN PROBLEMS OF THE ASA '33
4.i.i Sensors 33
4. I. Z Sensor/Electronics Loops 36
4. i. 3 Electronics and Interface 40
4. i. 4 Thermal and Mechanical 41
4.. 5 Testing 4Z
4.Z DISCUSSION OF MAJOR DESIGN PROBLEMS OF
COMPUTER SUBSYSTEMS (AEA AND DEDA) 47
: 4.2. i Major Design Changes 47
' 4.2. Z Mechanical Design Problems 49
i 4.2.3 Residual Problem Areas 50
4.3 DISCUSSION OF MAJOR DESIGN PROBLEMS OF
SOFTWARE 5i
4.3,i Softwired Program 51
4.3.Z Hardwired Program 54
: ' 4.4 DISCUSSION OF MAJOR PROBLEMS IN SYSTEMS
LEVEL TESTING 54
i 4.4. i Integration Test Problems 54
4.4.2 System Performance Test Problems 55
APPENDIX: DETAILED DESCRIPTION OF MAJOR SUB-
ASSEMBLIES, SOFTWARE, AND SYSTEM
LEVEL TESTING 57
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1969024052-007
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I ILLUSTRATIONS
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" i Z-1 Abort Guidance System Assemblies 3
Z-2 AGS Functional Block Diagram 4
• _ Z-3 Co-Elliptic Rendezvous Flight Profile 5
Z-4 ASA Linear Vibration Requirement 9
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ii!_' Z-5 ASA Rotational Vibration Requirement 9
_: I Z-6 AGS Design Limit Sinusoidal Vibration 9
_:_, Z-7 AGS Design Limit Random Vibration 9
I 4-! Capacitor C4 Adjust in Accelerometer 35
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1969024052-008
ABBREVIATIONS "I
ACE Automatic checkout equipment
AEA Abort electronics assembly
AGS Abort guidance system -_
ASA Abort sensor assembly
BTME Bench test maintenance equipment l
,J
CDH Constant delta h
CDU Coupling data unit
CLR Clear
C]O Checkout
CSD Cross spectral density
CSI Coelliptic sequence initiate
CSM Command and service module
T
D/A Digital/analog
DEDA Data entry and display assembly
DMCP Design mission computer program ,-_
DRB Design Review Board
%
DTL Diode transistor logic ,L.
EMI Electromagnetic interference ..
ENT R Enter -;_!
EPC Earth prelaunch calibration _
/
ERC Electronic Research Center
FDAI Flight Director Attitude Indicator *-!;
FEB Functional electronic block (thin-film hybrid circuit)
FP Flight program "_
FS Flight simulation a
-: g Acceleration due to gravity '_'
vill
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] 969024052-009
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i:_.':- GAEC Grumman Aircraft Engineering Corporation
"_i::'-|_ GMT Greenwich Mean Time
_';_;_ GSE Ground Support Equipment
'_"" I HVSIR H-vector spin input rectification
J
Hz Hertz
l ICS Interpretive computer simulation
ID Identification
t IMU Inertial measurement unit
_,_':' I/0 Input/output
_--_..:
_- LM Lunar Module
:]I__,/%,'. LOS Line of sight
_"_'_ I
_' LSB Least significant bits
_ MIT/11, Massachusett_ Institute of Technology Instrumentation
_..., Laboratory
_.:_, MSB Most significant bits
_ii MSC Manned Spacecraft Center
:_i I MSFN Manned space flight network
:i_':_. i MTBF Mean time between failure
"_;_! i PGNCS Primary Guidance, Navigation, and Control System
per
_i:' PPS Pulses second
_!:' I PSD Power spectral density
:_._ PTSA Pulse torque servoamplifier
" RCS Reactor control system
_i' I RFP Request for proposal
-;_,:- SCP Software change proposal
_ I SMRD Spin motor rotation detector
._:, T LM Telemetry
_" TPi Transfer phase initiate
_, iI
._._ UACSC United Aircraft Corporation System Center
)"i"_, WSMR White Sands Missile Range
,¢,..._'
_"i__ |X
] 969024052-0] 0
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1' 1 SUMMARY
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This report presents a survey of the system also provides a means of moni-
design a_.d development of the Abort toting the perform.-.mce of the PGNCS
Guidance System for the Apollo Lunar for fault detection.
,_ Module. Section 3 documents the evolution o_
The Lunar Module Abort Guidance the Abort Guidance System (AGS)design
• System, which is described in Section and summarizes the historical design
2, is a-strapdown, all-attitude, inertial development of subassemblies and soft-
guidance system being developed and ware. Section 4 presents the major
produced by TRW Systems Group for design problems that have developed to
_=. NASA's Manned Spacecraft C _nter un- date. Since the system is in the late
. der subcontract to Grumman Aircraft /stages of development, but has not yet :
_ Engineering Corporation. This system been flight-tested, it is po,ssible that
provides the capability for safely re- additional problem areas _vill appear,
_ tMurondiunlge tihne thaestruonnaliuktesly teoventhte oCfomamParni-d aanndy deevseingtn, ci_hamngaeys, bewidllesirbaeblerequirteod.writeIn
mary Guidance, Navigation, and Con- an addendum to this report at the end of
trol System (PGNCS) failure either the development cycle after the system
t! disurionng thdeescluennta,r suwrhfailcee, the orLundaurringModule hAasdetbaeileend sudbejescctreidption to opoferatthieonalmajor usaAgGe.S
,_ ascent from the lunar surface to the subassemblies, software, and °,-stern
Command Module. The abort guidance leveltesting is contained in the Appendix.
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