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TRANSCRIPT
MCDONNELL DOUGLAS ASTRONAUTICS COMPANY
HOUSTON DIVISION
SPACE TRANSPORTATION SYSTEMS ENGINEERING AND OPERATIONS SUPPORT
WORKING PAPER NO. 1.0-WP-VA86001-02
INDEPENDENT ORBITER ASSESSMENT
ANALYSIS OF THE DPS SUBSYSTEM
L_
24 OCTOBER 1986
This Working Paper is Submitted to NASA under
Task Order No. VA86001, Contract NAS 9-17650
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HJ ULowery
PREPARED BY : / --
K.C. Pietz //
PREPARED BY: __
W.A. Haufler/
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APPROVED
Independent OrbiterAssessment
i i/,;APPROVED BY:._(_- /_ _- ,:_
G.W. EFnori
Technical Manager
Independent Orbiter
Assessment
W.F. Huning
Deputy Program ManagerSTSEOS
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https://ntrs.nasa.gov/search.jsp?R=19900001608 2020-05-16T10:24:53+00:00Z
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CONTENTS
1.0 EXECUTIVE SUMMARY
Page
1
2.0 INTRODUCTION 4
2.1 Purpose 4
2.2 Scope 4
2.5 Analysis Approach 4
2.4 DPS Ground Rules and Assumptions 5
3.0 SUBSYSTEM DESCRIPTION
3.1 Design and Function 63.2 Interfaces and Locations 7
3.5 Hierarchy 7
4.0 ANALYSIS RESULTS 18
4.! Analysis Results MDM 19
4.2 Analysis Results GPC 19
4.3 Analysis Results MCDS 19
4.4 Analysis Results DBC 19
4.5 Analysis Results DBIA 19
4.6 Analysis Results MMU 20
4.7 Analysis Results EIU 20
5.0 REPERENCES 21
APPENDIX A ACRONYMS A-I
APPENDIX B DEFINITIONS, GROUND RULES, AND ASSUMPTIONS B-I
B.I
B.2
B.3
Definitions B-2
Project Level Ground Rules and Assumptions B-4
Subsystem Specific Ground Rules and Assumptions B-7
APPENDIX C DETAILED ANALYSIS
APPENDIX D POTENTIAL CRITICAL ITEMS
C-I
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List of Figures
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
1 - DPS OVERVIEW ANALYSIS SUMMARY
2 - DPS SUBSYSTEM OVERVIEW
3 - DPS MULTIPLEXER/DEMULTIPLEXER (MDM)
4 - DPS GPC CENTRAL PROCESSING UNIT (CPU)
5 - DPS GPC INPUT/OUTPUT PROCESSOR (IOP)
6 - DPS MCDS FUNCTIONAL BLOCK DIAGRAM
7 - DPS MCDS8 - DPS DATA BUS COUPLERS
9 - DPS MASS MEMORY UNIT (MMU)
Figure I0 - DPS ENGINE INTERFACE UNIT (EIU)
Figure ll - DATA PROCESSING SUBSYSTEM (DPS)
List of Tables
Table
Table
I - SUMMARY OF POSSIBLE FAILURE MODES
AND CRITICALITIES
II - SUMMARY OF POTENTIAL CRITICAL ITEMS
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Independent Orbiter Assessment
Analysis of the DPS Subsystem
1.0 EXECUTIVE SUMMARY
The McDonnell Douglas Astronautics Company (MDAC) was selected in
June 1986 to perform an Independent Orbiter Assessment (IOA) of
the Failure Mode and Effects Analysis / Critical Items List
(FMEA/CIL). Direction was given by the STS Orbiter and GFE
Projects Office to perform the hardware analysis using the
instructions and ground rules defined in the Rockwell Desk
Instructions 100-2G. The IOA approach features a top-down
analysis of the hardware to independently determine failure
modes, criticality, and potential critical items. This report
documents the independent analysis results corresponding to the
Orbiter Data Processing System (DPS) hardware.
The DPS hardware is required for performing critical functions of
data acquisition, data manipulation, data display, and data
transfer throughout the Orbiter. Specifically, the DPS hardware
consists of the following components:
o Multiplexer/Demultiplexer (MDM)
o General Purpose Computer (GPC)
o Multifunction CRT Display System (MCDS)
o Data Buses and Data Bus Couplers (DBC)
o Data Bus Isolation Amplifiers (DBIA)
o Mass Memory Unit (MMU)
o Engine Interface Unit (EIU)
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The IOA analysis process utilized available DPS hardware drawings
and schematics for defining hardware assemblies, components, andhardware items. Each level of hardware was evaluated and
analyzed for possible failure modes and effects. Criticality was
assigned based upon the severity of the effect for each failuremode.
Figure 1 presents a summary of the failure criticalities for each
of the seven major subdivisions of the DPS. A summary of the
number of failure modes, by criticality, is also presented below
with hardware criticality first and functional criticalitysecond.
I Summary of Failure Modes By Criticality (HW/F) I
I...... Jn_ me mmm_m_mm_m.
I Criticality: i/i 2/IR i 2/2 [ 3/IRI 3/2RI 3/3 I TOTAL I
I J i I J I JI Number : 0 2 I 0 [ 56 1 22 I 5 1 85 I4
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Figure 1 - DPS OVERVIEW ANALYSIS SUMMARY
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For each failure mode identified, the criticality and redundancy
screens were examined to identify critical items. A summary of
potential critical items is presented as follows:
IIIIIIIIIIImIIIIIIII "IIIIIII_
I Summary of Potential Critical Items (HWIF) II ........................... I.I criticality: I Zll I 21ZRI 212 i 31IRI 312RI 313 I TOTAL II I I I I I I I II Number : I 0 I 2 I 0 I 0 I 0 I 0 I 2 I+ +
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Due to the extensive redundancy built into the DPS the number of
critical items are few. Those identified resulted from premature
operation and erroneous output of the GPCs.
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2.0 INTRODUCTION
2.1 Purpose
The 51-L Challenger accident prompted the NASA to readdress
safety policies, concepts, and rationale being used in the
National Space Transportation System (NSTS). The Space
Transportation System (STS) Systems office has undertaken the
task of reevaluating the FMEA/CIL for the Space Shuttle design.
The MDAC is providing an independent assessment of the Orbiter
FMEA/CIL reevaluation results for completeness and technical
accuracy.
2.2 Scope
The scope of the independent FMEA/CIL assessment activity _.......
encompasses those Shuttle orbiter subsystems and GFE hardware
identified in the Space Shuttle Independent FMEA/CIL Assessment
Contractor Statement of Work. Each subsystem analysis addresses
hardware, functions, internal and external interfaces, and
operational requirements for all mission phases.
2.3 Analysis Approach
The independen£ anilysis approach is a top-down analysis
utilizing as-built drawings to breakdown the respective subsystem
into components and low-level hardware items. Each hardware item
is evaluated for failure mode, effects, and criticality. These
data are documented in the respective subsystem analysis report,
and are used to assess the NASA and Prime Contractor FMEA/CIL
reevaluation results. The IOA analysis approach is summarized in
the following Steps 1.0 through 3.0. Step 4.0 summarizes the
assessment of the NASA and Prime Contractor FMEAs/CILs that is
performed and documented at a later date.
Step 1.0 Subsystem Familiarization
1.1 Define subsystem functions
1.2 Define subsystem components
1.3 Define subsystem specific ground rules and
assumptions
Step 2.0 Define subsystem analysis diagram
2.1 Define subsystem
2.2 Define major assemblies
2.3 Develop detailed subsystem representations
Step 3.0 Failure events definition3.1 Construct matrix of failure modes
3.2 Document IOA analysis results
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Step 4.0 Compare IOA analysis data to Rockwell/NASA FMEA/CIL4.1 Resolve differences
4.2 Review in-house
4.3 Document assessment issues
4.4 Forward findings to Project Manager
2.4 DPS Ground Rules and Assumptions
The DPS ground rules and assumptions used in the IOA are defined
in Appendix B. The subsystem specific ground rules were defined
to limit the analysis to single-failed-parts for each failure
mode. A subset of the failure mode keywords were identified for
the DPS team. This allowed for commonality in the analysis
results.
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3.0 SUBSYSTEM DESCRIPTION
3.1 Design and Function
The DPS consists of that hardware required for data acquisition,
data manipulation, data display, and data transfer on the
Orbiter, and includes the five onboard computers and their
interfaces. Reference Figure 2. More specifically, the DPS
consists of the following components:
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i. Twelve MDM units which convert and format data at the
remote locations. Each MDM_has internal redundancy and
consists of a Multiplexer Interface Adapter (MIA),
Sequential Control Unit (SCU), Input/Output Module,
Analog To Digital Converter, and Power Supply. They
convert and format serial digital GPC commands into
parallel discrete, digital, and analog data for transfer
to vehicle subsystem hardware. They also convert and
format parallel discrete, digital, and analog data from
vehicle subsystems into serial digital data for
transmission to the GPCs. Reference Figure 3.
2. Five GPCs each consisting of a Central Processing Unit
(CPU) and Input/Output Processor (IOP). The CPU
functionally consists of an Arithmetic Logic Unit, Local
Store, Master Bus Control Unit, Data Flow Multiplexer,
Micro-code control r unit, CPU Timer, Interrupt Logic, Main
Memory Timing Page, Timers, Address Bus Control, Main
Memory, and Power Supply. The IOP contains Control
Monitor, IOP Main Memory, Channel Control, Direct Memory
Access Queue, Arithmetic Logic Units, Local Store, Micro-
code store and Decode, MIAs, and Time-slice and
Multiplexing. One of the functions of the GPCs is to
support guidance, navigation, and control requirements of
the vehicle. They provide for the monitoring and control
of vehicle subsystems. They also check for data
transmission errors and crew input error. Vehicle system
failures and out-of-tolerance conditions are annunciated
by the GPCs. Reference Figure 4 and Figure 5.
3. The MCDS consisting of three Keyboard Units (KU), four
Display Units (DU) and four Display Electronics Units
(DEU). Each KU has a Key, Switch and Light. The DU
consists of X/Y Deflection Amplifiers, Video Amplifiers,
Cathode-Ray Tube, BITE and Power Supplies. The DEU has
an Oscillator, Memory, Key-board Adapter, Symbol
Generator, MIA, Control Logic, BITE, Load Switch, and
Power Supplies. The subsystem provides for crew/vehicle
interface via a keyboard and CRT display. The crew can
interact with the subsystems with keyboard entries and
executions. Reference Figure 6 and Figure 7.
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4. Thirty serial digital data buses are connected to the Bus
Terminal Units (BTUs) via 227 DBCs. The DBCs are shown
in Figure 8.
5. Two DBIAs provide the amplification necessary to drive
the stubs and provide isolation when the stubs are opened
or shorted at the umbilicals.
6. Two MMUs containing MIAs, Read Electronics, Write
Electronics, Mass Memory Control Logic, Power Supply with
Switch, Tape Transport Mechanism with a motor, tape and
heads. The mass memory unit stores programs for loading
into the GPCs and the MCDS. Reference Figure 9.
7. Three EIUs which provide status and command capability of
the main engines. The EIU contains an MIA, BITE, Status
Buffer, Controller Interface Adapter, Operational
Interface Element, Data Status and Power Supply. The EIU
transfers main engine control commands from the GPC and
main engine status for use by the GPC, the GSE launch
processing system, and the operational instrumentation
system. Reference Figure 10.
The DPS interfaces with many onboard Orbiter systems including
the Main Propulsion System, Solid Rocket Boosters, Reaction
Control System (RCS), Orbital Maneuvering System (OMS), Air
Surface Controls used for guidance and control, Nose-wheel
Steering, and the Master Timing Units.
3.2 Interfaces and Locations
The DPS hardware is located throughout the Orbiter. The
composite data bus network provides the hardware interfaces
between the GPCs and all other avionics subsystems that
communicate via a digital data format. Reference Figure ll.
GPCs 1 and 4 are located in Avionics Bay 1 while GPCs 2 and 5 are
located in Avionics Bay 2, to provide separation of redundancy.
GPC 3 is located in Avionics Bay 3. Each GPC interfaces to all
Flight Critical MDMs, however only one GPC normally communicates
to only one FF and one FA MDM during ascent and entry dynamic
flight.
3.3 Hierarchy
Figure 2 illustrates the hierarchy of the DPS hardware and the
corresponding subcomponents. Figures 3 through i0 comprise the
detailed system representations.
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COUPLERS (DBC) I
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4.0 ANALYSIS RESULTS
Detail analysis results for each of the identified failure modes
are presented in Appendix C. Table I presents a summary of thefailure criticalities for each of the seven major subdivisions of
the DPS. Further discussion of each of these subdivisions and
the applicable failure modes is provided in subsequent
paragraphs.
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TABLE I Summary of Possible Failure Modes and Criticalities
Criticality:
MDM
GPC
MCDS
DBC
DBIA
MMU
EIU
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- - 12
-- 5 --
TOTAL 0 2 0 56 22
3/3 TOTAL
- 36
2 13
1 15
- 1
- 1
1 13
1 6
5 85
Of the 85 failure modes analyzed, no'single faiiures were
determined to result in loss of crew or vehicle, and two were
determined to result in loss of mission. A summary of the ....
potential critical items is presen£ed in Table II. Appendix D
presents a cross reference between each potential critical item
(PCI) and a specific worksheet in Appendix C.
I TABLE II Summary of Potential Critical Items I
I .......... iI Criticality: i i/I l 2/IR I 2/2 1 3/IR I 3/2R I 3/3 1 TOTAL i
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4.1 Analysis Results MDM
The MDM analysis considered nine failure modes for four groups of
MDMs; namely FF, FA, PF, LF/LA as illustrated in Figure 3. Most
of the criticalities were 3/IR. No PCIs were found.
4.2 Analysis Results GPC
The GPC analysis was subdivided into IOP and CPU failures.
Generic black box failures were analyzed with causes stemming
from failures of the subcomponents such as the MIA, as shown in
Figure 4 and Figure 5. Two PCIs were identified and are listed
in Appendix D.
4.3 Analysis Results MCDS
The MCDS consists of the KU, DU, and DEU. Functional failures of
components were analyzed. These components are shown
functionally in Figure 6 and Figure 7. Nine failure modes were
identified and fifteen worksheets were generated. No PCIs were
identified.
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4.4 Analysis Results DBC
Thirty serial digital data buses connect the GPC IOPs to the BTUs
via 227 DBCs. The DBCs functional components are shown in
Figure 8. Two failure modes were identified and one worksheet
was generated. No PCIs were identified.
4.5 Analysis Results DBIA
The DBIAs consist of components required to provide isolation
between the Orbiter Launch/Boost Data Buses and the SRBs and
associated GSE for each. Four failure modes were identified and
one worksheet was generated. No PCIs were identified.
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4.6 Analysis Results MMU
The MMU analysis investigatedfailures in the individual
components of power supply, read and write electronics, tape
transport mechanism, MIA and control logic. These are shown
functionally in Figure 9. The power switch and RPC were also
investigated. Most of the failures were criticality 3/2R. No
PCIs were identified.
4.7 Analysis Results EIU
The EIU provides commands to and status of the Main Engines.
There were no failure modes analyzed that resulted in a PCI being
defined. The EIU is shown functionally in Figure 10.
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5.0 REFERENCES
Reference documentation available from NASA and Rockwell was used
in the analysis. The documentation used included the following:
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1. ICD 13M15000, Vehicle/Main Engine Interface Control
Document, Rev. U, 6-18-85
2. JSC-18819, DPS Console Handbook, 8-1-84
3. JSC-19041, MPS System Briefs, 10-1-84
4. JSC-18820, DPS System Briefs, 4-20-85
5. VS70-971102, Integrated System Schematic Rev. D, 9-28-85
6. JSC-17239, Booster Console Handbook, 10-17-85
7. JSC-12770, Shuttle Flight Operations Manual, Volume 5,
Data Processing System, 3-24-84
8. JSC 12820, STS Operational Flight Rules, Final PCN-3,
6-28-85
9. JSC 11174, Space Shuttle Systems Handbook, Rev. C, DCN-5,
9-13-85
i0. 100-2G, Rockwell International Reliability Desk
Instruction Flight Hardware FMEA and CIL, 1-31-84
ii. V72 Vol III, Operations and Maintenance Requirements and
Specification Document - Orbiter OMRSD - DPS, 6-13-86
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A/DAIDAIS
ALU
AOA
AOD
ATOBFC
BFS
BITE
BSSBTU
CIL
CPU
CRITCRT
C&W
DBCDBIA
DDU
DEU
DIHDIL
DMA
DOH
DOLDPS
DU
EIUEVA
FA
FCOS
FFFM
FMEAGPC
GSE
IMU
IOAIOM
IOPIPL
KU
LF
LL
LPS
LRLRU
MC
MCDS
MCIU
APPENDIX AACRONYMS
- Analog to Digital- Analog Input Differential
- Analog Input Single-ended
- Arithmetic Logic Unit- Abort Once Around
- Analog Output Differential- Abort To Orbit
- Backup Flight Controller
- Backup Flight System- Built-In Test Equipment
- Backup System Services- Bus Terminal Unit
- Critical Items List
- Central Processing Unit
- Criticality
- Cathode Ray Tube
- Caution and Warning System
- Data Bus Coupler- Data Bus Isolation Amplifier
- Display Driver Unit
- Display Electronics Unit- Discrete Input High
- Discrete Input Low
- Direct Memory Access- Discrete Output High
- Discrete Output Low °
- Data Processing System
- Display Unit- Engine Interface Unit
- Extra Vehicular Activity
- Flight Aft
- Flight Control Operating System- Flight Forward- Failure Mode
- Failure Mode and Effects Analysis
- General Purpose Computer
- Ground Support Equipment- Inertial Measurement Unit
- Independent Orbiter Assessment
- Input/Output Module
- Input/Output Processor- Initial Program Load
- Keyboard Unit- Launch Forward
- Launch Left
- Launch Processing System
- Launch Right
- Line Replaceable Unit
- Memory Configuration- Multifunction CRT Display System
- Manipulator Controller Interface Unit
A-I
MDACMDMMECMIAMMMMUMTUNA
NASA
NSTSOA
OF
OMRS D
OMS
OPSPCI
PCM
PF
RCSRHC
RI
RM
RMSRPC
RS
RTLSSCU
SIO
SMSRB
SSME
STS
SW
TACTAL
TD
THCVDC
- McDonnell Douglas Astronautics Company
- Multiplexer/Demultiplexer- Main Engine Controller
- Multiplexer Interface Adapter
- Major Mode
- Mass Memory Unit- Master Timing Unit
- Not Applicable- National Aeronautics and Space Administration
- National Space Transportation System
- Operational Aft
- Operational Forward- Operational Maintenance Requirements and
Document
- Orbital Maneuvering System
- Operational Sequence- Potential Critical Item
- Pulse Code Modulation
- Payload Forward- Reaction Control System- Rotational Hand Controller
- Rockwell International
- Redundancy Management
- Remote Manipulator System- Remote Power Controller
- Redundant Set
- Return To Landing site
- Sequential Control Unit
- Serial Input / Output- Systems Management- Solid Rocket Booster
- Space Shuttle Main Engine- Space Transportation System-- Software
- Tacan
- Transatlantic .Abort Landing- Touch Down- Translational Hand Controller
- Volts Direct Current
Specifications
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APPENDIX B
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DEFINITIONS, GROUND RULES, AND ASSUMPTIONS
B.1
B.2
B.3
Definitions
Project Level Ground Rules and Assumptions
Subsystem-Specific Ground Rules and Assumptions
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APPENDIX B
DEFINITIONS, GROUND RULES, AND ASSUMPTIONS
B.I Definitions
Definitions contained in Reliability Desk Instruction, 100-2GRockwell International, 31 January 1984, were used with the
following amplifications and additions.
ABORT DEFINITIONS:
RTLS - begins at transition to OPS 6 and ends at transition to
OPS 9, post-flight.
TA___L- begins at declaration of the abort and ends at transition
to OPS 9, post-flight.
AO__AA- begins at declaration of the abort and ends at transition
to OPS 9, post-flight.
AT___O- begins at declaration of the Abort To Orbit (ATO) and endsupon transition out of OPS i.
CREDIBLE (CAUSE) - an event that can be predicted or expected inanticipated operational environmental conditions. Excludes an
event where multiple failures must first occur to result inenvironmental extremes.
EFFECTS/RATIONALE - Description of the case which generated thehlghest criticaiity.
HIGHEST CRITICALITY - The highest criticalities determined in thephase-by-phase analysis.
MAJOR MODE _ - major sub-mode of software operational sequence(oPs).
__MC - Memory Configuration of Primary Avionics Software System(PASS).
MISSION - assigned performance of a specific orbiter flight withpayload/objective accomplishments such as launch window, orbitphasing, and altitude.
MULTIPLE ORDER FAILURE - describes the failure due to a singlecause or event of all units which perform a necessary (critical)function.
NORMAL GROUND TURNAROUND - begins at end of post-landing safingoperations and ends at beginning of prelaunch operations.
OP___SS- software operational sequence.
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PHASE DEFINTIONS:
PRELAUNCH PHASE - begins at Orbiter launch count-down
power-up and ends at moding to OPS Major Mode 102 (liftoff).
LIFTOFF MISSION PHASE - begins with SRB ignition (MM 102) and
ends at transition out of OPS i. (Synonymous with ASCENT).
ONORBIT PHASE - begins at transition to oPs 2 or oPs 8 and
ends upon transition out of OPS 2 or OPS 8.
DEORBIT PHASE - begins at transition to OPS Major Mode301 and ends at first main landing gear touchdown at landing
site.
LANDING/SAFING PHASE - begins at first main geartouchdown at the landing site and ends with the completion of
post-landing safing operations.
READILY DETECTABLE - easily and obviously observable and
comprehensable by flight and/or ground personnel. Readilydetectable requires the capability of getting a crewmember to
respond to a problem notification via real-time monitored
displays, on-board alerts, visual indications, or groundnotification. (Ground notification must not be considered unlesssufficient time is available to perform corrective action to
preclude the critical consequences of the failure, using worst-
case telemetry and data.)
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APPENDIX BDEFINITIONS, GROUNDRULES, AND ASSUMPTIONS
B.2 IOA Project Level Ground Rules and Assumptions
The philosophy embodied in Reliability Desk Instruction, 100-2GRockwell International, 31 January 1984, was employed with the
following amplifications and additions•
I• The operational flight software is an accurate
implementation of the Flight System Software Requirements
(FSSRs).
RATIONALE: Software verification is out-of-scope ofthis task.
• After Lift-Off, any parameter which is monitored by systemmanagement (SM) or which drives any part of the Caution and
Warning System (C&W) will support passage of Redundancy
Screen B for its corresponding hardware item.
RATIONALE: Analysis of on-board parameter availibility
and/or the actual monitoring by on-board
personnel is beyond the scope of this task.
1 Any data employed with flight software is assumed to be
functional for the specific vehicle and specific mission
being flown•
RATIONALE: Mission data verification is out-of-scope ofthis task.
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All hardware (including firmware) is manufactured and
assembled to the design specifications/drawings.
RATIONALE: Acceptance and verification testing is
designed to detect and identify problemsbefore the item is approved for use.
All Flight Data File crew procedures will be assumedperformed as written, and will not include human error in
their performance.
RATIONALE: Failures caused by human operational error
are out-of-scope of this task.
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g All hardware analyses will, as a minimum, be performed at
the level of analysis existent within NASA/prime contractor
Orbiter FMEA/CILs, and will be permitted to go to greater
hardware detail levels but not lesser•
RATIONALE: Comparison of MDAC IOA analysis results with
other analyses requires that both analyses
be performed to a comparable level of detail.
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•
•
The presence of a failure detectability parameter in
telemetry is sufficient justification for passing Redundancy
Screen B. Verification that the parameter is actually
monitored by ground based personnel is not required.
RATIONALE: Analysis of mission-dependent telemetryavailability and/or the actual monitoring of
applicable data by ground-based personnel is
beyond the scope of this task.
For the purpose of passing Redundancy Screen A, the term
"normal ground turnaround" shall include the pre!aunch
mission phase.
RATIONALE: Some items cannot be checked out until after
propellant loading or main engine
conditioning begins although the vehicle is
still on the ground• This philosophy was
adopted by the Level II PRCB.
At a minimum, loss of mission is declared when a failure
results in a launch delay beyond the pre-planned launch
window.
RATIONALE: Subsystem failures can occur near thenominal launch time. When these failures
result in a launch delay, a loss of mission
occurs even though the vehicle never enters
into any in-flight mode.
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i0. The determination of criticalities per phase is based on the
worst case effect of a failure for the phase being analyzed.
The failure can occur in the phase being analyzed or in
any previous phase, whatever produces the worst case effects
for the phase of interest.
RATIONALE: Assigning phase criticalities ensures a
thorough and complete analysis.
B-5
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ii. The "Next Related Failure" when used in determining hardware
criticality 2 (one failure away from loss of crew/vehicle)is defined as the worst case failure of next redundant item.
This definiton applies only to dual redundancy by definition.
RATIONALE: The RI Desk Instruction Appendix B, 3.1.1.1states the definiton of criticality 2. For
the purpose of this analysis "Next relatedFailure" is clearly defined to ensure
project consistancy.
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APPENDIX B
DEFINITIONS, GROUND RULES, AND ASSUMPTIONS
B.3 DPS-Specific Ground Rules and Assumptions
The IOA analysis was performed to the component or assembly level
of the DPS subsystem. The analysis considered the worst caseeffects of the hardware or functional failure on the subsystem,
mission, and crew and vehicle safety.
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l. Electronics were considered to have the following
credible failure modes.
a. Premature operation
b. Erroneous/erratic output
c. No output
RATIONALE: These failure mode keywords were the
most applicable for the DPS electronics
hardware.
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APPENDIX C
DETAILED ANALYSIS
This section contains the IOA analysis worksheets employed during
the analysis of the DPS subsystem. The information on theseworksheets is intentionally similar to the FMEA's written byRockwell and the NASA. Each of these sheets identifies the item
being analyzed, and parent assembly, as well as the function. Foreach failure mode, the possible causes are outlined, and theassessed hardware and functional criticality for each mission
phase is listed, as described in the Rockwell Desk Instructions100-2G. Finally, effects are entered at the bottom of each
sheet, and the worst case criticality is entered at the top.
LEGEND FOR IOA ANALYSIS WORKSHEETS
w
Hardware Criticalities :
1 = Loss of life or vehicle2 = Loss of mission
3 = Non loss of life or vehicle or mission
Functional Criticalities :
IR = Redundant identical hardware components or redundant
functional paths all of which, if failed, could causeloss of life or vehicle.
2R = Redundant identical hardware components or redundant
functional paths all of which, if failed, could causeloss of mission.
Redundancy Screen A :
1 = Is Checked Out PreFlight2 = Is Capable of Check Out PreFlight
3 s Not Capable of Check Out PreFlight4 = Do Not Know
Redundancy Screens B and C :P = Passed Screen
F = Failed Screen
NA = Not Applicable
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INDEPENDENTORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
100 ABORT:
HDW/FUNC3/IR
3/IR
ITEM:
FAILURE MODE:
MDM FFI,FF2,FF3,FF4LOSS OF OUTPUT TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i) DPS2) MULTIPLEXER-DEMULTIPLEXERS (MDM)
3) FLIGHT CRITICAL FORWARD MDM (FFI..4)
4)s)6)v)s)9)
C i TiCALITIESFLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/ 2R RTLS : 3/ IRLIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ]
LOCATION: AV BAY 1,2,3,2PART NUMBER: MC615-0004-6110,5110
B [ P ] C [ P ]
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM,BUT NOT ALLOWED DURING ASCENT UNTIL AFTER 2ND MDM FAILURE. IF
ALL REDUNDANCY FAILS, LOSE USE OF IMU TORQUING, FORWARD RCS JETS,
HAND CONTROLS (THC,RHC), MOST SWITCHES AND INDICATORS.
REFERENCES:
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: i01 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
MDM FFI,FF2,FF3,FF4
LOSS OF OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
S)
6)
V)
8)
9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL FORWARD MDM (FFI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/1R
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAY 1,2,3,2
PART NUMBER: MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF IMU TORQUING,
FORWARD RCS JETS, HAND CONTROLS (THC,RHC), MOST SWITCHES AND
INDICATORS.
REFERENCES:
C-3
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY HDW/FUNCSUBSYSTEM: DPS FLIGHT: 3/IR
MDAC ID: 102 ABORT: 3/IR
ITEM: MDM FFI,FF2,FF3,FF4FAILURE MODE: ERRONEOUS OUTPUT TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I) DPS2) MULTIPLEXER-DEMULTIPLEXERS (MDM)
3) FLIGHT CRITICAL FORW_D MDM (FFI..4) _4)s)6)
8)9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR _LIFTOFF: 3/1R TAL: 3/1R
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/iR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAY 1,2,3,2PART NUMBER: MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDMAFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM, BUTNOT ALLOWED DURING ASCENT UNTIL AFTER 2ND MDM FAILURE. IF ALL
REDUNDANCY FAILS, LOSE USE OF IMU TORQUING, FORWARD RCS JETS,
HAND CONTROLS (THC,RHC), MOST SWITCHES AND INDICATORS.
REFERENCES:
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 103 ABORT:
HDW/FUNC
3/iR
3/IR
ITEM:
FAILURE MODE:
MDM FFI,FF2,FF3,FF4ERRONEOUS OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)
2)3)4)s)6)v)s)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL FORWARD MDM (FFI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,2,3,2
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF IMU TORQUING,
FORWARD RCS JETS, HAND CONTROLS (THC,RHC), MOST SWITCHES AND
INDICATORS.
REFERENCES:
C-5
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 104 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
MDM FFI,FF2,FF3,FF4PREMATURE OPERATION TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL FORWARD MDM (FF1..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,2,3,2
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:THIS FAILURE ON EITHER PORT CAN INTERFERE WITH FCOS RETURNING
DATA FROM OTHER BTU(S) AND CAUSE HEALTHY BTU(S) TO BE BYPASSED.
PORT MODING WILL NOT FIX A BLABBING MDM. POWER CYCLING MAY RESET
ELECTRONICS, BUT CANNOT BE PERFORMED DURING ASCENT (POWER
SWITCHES CANNOT BE REACHED), AND WILL NOT ALWAYS STOP PREMATURE
OPERATIONS. IF ALL REDUNDANCY FAILS, LOSE USE OF IMU TORQUING,
FORWARD RCS JETS, HAND CONTROLS (THC,RHC), MOST SWITCHES AND
INDICATORS.
REFERENCES:
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 105 ABORT:
HDW/FUNC
3/IR
3/1R
ITEM: MDM FFI,FF2,FF3,FF4
FAILURE MODE: PREMATURE OPERATION TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL FORWARD MDM (FF1..4)
CRiTiCALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/1R TAL: 3/1R
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/1R ATO: 3/IR
LANDING/SAFING: 3/1R
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 1,2,3,2
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF IMU TORQUING,
FORWARD RCS JETS, HAND CONTROLS (THC,RHC), MOST SWITCHES AND
INDICATORS.
REFERENCES:
C-7
=
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86suBSYSTEM: DPS
MDAC ID: 106
ITEM: MDM FFI,FF2,FF3,FF4
FAILURE MODE: SELECTED ALL CHANNELS WRONG
LEAD ANALYST: W. A. HAUFLER
HIGHEST CRITICALITY
FLIGHT:
ABORT:
SUBSYS LEAD: B. ROBB
HDW/FUNC
3/1R3/1
BREAKDOWN HIERARCHY:
I)2)3)4)s)
8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL FORWARD MDM (FFI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART _BER:
AV BAY 1,2,3,2
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
THE GP¢'S FCOS AND THE _LR_$ WOULD REJE_T_A_L_L_DATA FROM T HA_TMDM
EXCEPT ANY DATA THAT HAPPENED TO BE IN THE SAME FORMAT AS THE
EXPECTED DATA. REDUNDANCY MGT. SOON DETECTS AND BYPASSES THAT
MDM, AND THE EFFECTS OF WRONG DATA INPUT OR OUTPUT IS MINIMIZED.
IF ALL REDUNDANCY FAILS, LOSE USE OF IMU TORQUING, FORWARD RCS
JETS, HAND CONTROLS (THC,RHC), MOST SWITCHES AND INDICATORS.
REFERENCES:
E
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 107 ABORT:
HDW/FUNC
3/IR
3/IR
ITEM:
FAILURE MODE:MDM FFI,FF2,FF3,FF4STUCK ON A CONSTANT OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)
2)
3)
4)s)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL FORWARD MDM (FFI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 1,2,3,2
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF IMU TORQUING,
FORWARD RCS JETS, HAND CONTROLS (THC,RHC), MOST SWITCHES AND
INDICATORS.
REFERENCES:
m
C-9
INDEPENDENTORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 108 ABORT:
HDW/FUNC
3/IR
3/IR
ITEM:
FAILURE MODE:MDM FFI,FF2,FF3,FF4FALSELY STUCK ON BUSY MODE
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)2)3)4)S)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL FORWARD MDM (FFI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 1,2,3,2
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION, SCU BUSY CROSS-
STRAP STUCK HIGH
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM, BUT
NOT ALLOWED DURING ASCENT UNTIL AFTER 2ND MDM FAILURE. IF ALL
REDUNDANCY FAILS, LOSE USE OF IMU TORQUING, FORWARD RCS JETS,
HAND CONTROLS (THC,RHC), MOST SWITCHES AND INDICATORS.
REFERENCES:
g
I
mR
mm
i
B
EI
m
m
U
Ei
I
I
g
J
m
m
l
m
C-IO
I
I
L
u
m
w
w
k_
u
u
w
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 120 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
MDM FA1,FA2,FA3,FA4
LOSS OF OUTPUT TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)
2)
3)
4)
5)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FAI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:AV BAY 4,5,6,6
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM, BUT
NOT ALLOWED DURING ASCENT UNTIL AFTER 2ND MDM FAILURE. IF ALL
REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY FLAP, AILERONS,
RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES AND TANKS.
REFERENCES:
C-ll
INDEPENDENT ORBITER ASSESSMENTORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 121 ABORT:
HDW/FUNC
3/IR
ITEM:FAILURE MODE:
MDM FA1,FA2,FA3,FA4LOSS OF OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)2)3)4)S)6)V)S)9)
DPSMULTIPLEXER-DEMULTIPLEXERS
FLIGHT CRITICAL AFT MDM
L
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/1R TAL:
ONORBIT: 3/2R AOA:DEORBIT: 3/IR ATO:
LANDING/SAFING: 3/IR
HDW/FUNO3/IR _3/ZR3/IR3/ZR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] c[P]
LOCATION: AV BAY 4,5,6,6
PART NUMBER: MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORDPROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODYFLAP, AILERONS, RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES
AND TANKS.
REFERENCES:
I
mm
m
m
I
mm
mm
mm
mm
l
D
i
I
l
I
C-12
g
I
mm
z
w
u
w
I
w
W
w
w
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 122 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
MDM FA1,FA2,FA3,FA4
ERRONEOUS OUTPUT TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)2)3)4)s)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FA1..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION: AV BAY 4,5,6,6
PART NUMBER: MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM, BUT
NOT ALLOWED DURING ASCENT UNTIL AFTER 2ND MDM FAILURE. IF ALL
REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY FLAP, AILERONS,
RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES AND TANKS.
REFERENCES:
mmm
C-13
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
123 ABORT:
HDW/FUNC
3/IR
3/IR
ITEM:
FAILURE MODE:
MDM FA1,FA2,FA3,FA4
ERRONEOUS OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)3)4)5)6)T)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FAI..4)
C_ICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:
AV BAY 4,5,6,6
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION _ _
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY
FLAP, AILERONS, RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES
AND TANKS.
REFERENCES:
z
I
mm
mm
mm
m
l
m
l
mm
m
mmm
mmwI
mm
mm
I
mI
i
I
Bi
C-14 mm
g
m
w
=
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
124 ABORT:
HDW/FUNC
3/1R
311R
ITEM:
FAILURE MODE:
MDM FA1,FA2,FA3,FA4PREMATURE OPERATION TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
5)
6)
V)
s)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FAI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: .3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 4,5,6,6
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:THIS FAILURE ON EITHER PORT CAN INTERFERE WITH FCOS RETURNING
DATA FROM OTHER BTU(S) AND CAUSE GOOD BTU(S) TO BE BYPASSED.
PORT MODING WILL NOT FIX A BLABBI_GMDM. POWER CYCLING MAY RESET
ELECTRONICS, BUT CANNOT BE PERFORMED DURING ASCENT (POWER
SWITCHES CANNOT BE REACHED), AND WILL NOT ALWAYS STOP PREMATURE
OPERATIONS. IF ALL REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY
FLAP, AILERONS, RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES
AND TANKS.
REFERENCES:
w
C-15
=
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 125 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
MDM FA1,FA2,FA3,FA4
PREMATURE OPERATION TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)2)3)4)s)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FAI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/IR TAL:
ONORBIT: 3/2R AOA:
DEORBIT: 3/IR ATO:
LANDING/SAFING: 3/IR
HDW/FUNC3/IR3/IR3/IR3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:AV BAY 4,5,6,6
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS DOES NOTIDIRECTLYDETECT THIS ERROR VIA MDM RETURN WORDPROCESSING. FAULT TOLERANCE DEPENDSON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY
F_, AILERONS, RUDDER, SPEEDBRAKE, _DABILITY TO PURGE SSMES ....
AND TANKS.
REFERENCES:
m
mm
"m
m
m
m
I
mmB
m
I
I
m
mm
m
I
mmmm
c
m ,
s
mm
C-16 m
D
n
u
i
u
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 126 ABORT:
HDW/FUNC3/IR3/IR
ITEM: MDM FAI,FA2,FA3,FA4
FAILURE MODE: SELECTED ALL CHANNELS WRONG
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)2)3)4)5)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FA1..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 4,5,6,6
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:THE GPC'S FCOS AND THE LRUS WOULD REJECT ALL DATA FROM THAT MDM
EXCEPT ANY DATA THAT HAPPENED TO BE IN THE SAME FORMAT AS THE
EXPECTED DATA. REDUNDANCY MGT. SOON DETECTS AND BYPASSES THAT
MDM, AND THE EFFECTS OF WRONG DATA INPUT OR OUTPUT IS MINIMIZED.
IF ALL REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY FLAP,
AILERONS, RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES AND
TANKS.
REFERENCES:
w
C-17
u
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 127 ABORT:
ITEM:
FAILURE MODE:
MDM FA1,FA2.FA3,FA4STUC_ ON A CONSTANT OUTPUT TO LRU
HDW/FUNC
3/IR3/IR
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)s)
v)s)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FAI..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNCPRELAUNCH: 3/2R RTLS: 3/iR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/!R ....zDEORBIT: 3/IR ATo: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 4,5,6,6
MC6i5-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE: .........FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY
FLAP, AILERONS, RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES
AND TANKS.
REFERENCES:
[]mm
[]
z
I
i
i
[]
[]
m
[]
m
l
I
l
I
mm
C-18
U
mm
n
l
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 128 ABORT:
HDW/FUNC
3/IR3/IR
ITEM:
FAILURE MODE:
MDM FA1,FA2,FA3,FA4
FALSELY STUCK ON BUSY MODE
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)5)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
FLIGHT CRITICAL AFT MDM (FA1..4)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:AV BAY 4,5,6,6
MC615-0004-6110,5110
CAUSES: VIBRATION, CORROSION, CONTAMINATION, SCU BUSY CROSS-
STRAP STUCK HIGH
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM, BUT
NOT ALLOWED DURING ASCENT UNTIL AFTER 2ND MDM FAILURE. IF ALL
REDUNDANCY FAILS, LOSE USE OF AFT RCS, BODY FLAP, AILERONS,
RUDDER, SPEEDBRAKE, AND ABILITY TO PURGE SSMES AND TANKS.
REFERENCES:
C-19
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86SUBSYSTEM: DPSMDAC ID: 140
HIGHEST CRITICALITY
FLIGHT:ABORT:
ITEM: MDM PFI,PF2FAILURE MODE: LOSS OF OUTPUT TO GPC
HDW/FUNC
3/IR3/3
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)v)s)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)PAYLOAD FORWARD MDM (PF1..2)
CRITI!__CIALITiES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:LIFTOFF: 3/3 TAL:
ONORB_T: 3/IR AOA:
DEORBIT: 3/3 ATO:
LANDING/SAFING: 3/3
REDUNDANCY SCREENS:
HDW/FUNC3/3
3/33/5113/3
A[ I] B[P] C [ P]
LOCATION: AV BAY 1,2PART NUMBER: MC615-0004-6710,5710
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS/BSS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SWIGNORES THAT DATA. SYSTEM SOFTWARE BYPASSES MDM AFTER 2ND
CONSECUTIVE COMMFAULT, AND DISPLAYS FAULT MSG ON CRTS. PORT
MODING MAY NOT RECOVER MDM. IF ALL REDUNDANCY FAILS, LOSE
ABILITY TO RELEASE, OPEN, CLOSE, AND LATCH PAYLOAD BAY DOORS, ANDABILITY-TO CRADLE AND LATCH RMS ARM WITHOUT AN EVA.
REFERENCES:
l
l
ms
l
i
B
ms
m
i i
I
m
I
mm
m
mm
C-20g
z
ms
m
i
w
w
DATE:
SUBSYSTEM:
MDAC ID:
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
10/03/86 HIGHEST CRITICALITY
DPS FLIGHT:
141 ABORT:
HDW/FUNC
3/1R3/3
ITEM:
FAILURE MODE:
MDM PFI,PF2LOSS OF OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PAYLOAD FORWARD MDM (PFI..2)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/3 TAL:
ONORBIT: 3/IR AOA:
DEORBIT: 3/3 ATO:
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B [ P ]
HDW/FUNC
3/3
3/3
3/3
3/3
c[p]
LOCATION: AV BAY 1,2
PART NUMBER: MC615-0004-6710,5710
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS/BSS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT PF MDMS.
DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK SIGNALS. IF
ALL REDUNDANCY FAILS, LOSE ABILITY TO RELEASE, OPEN, CLOSE, AND
LATCH PAYLOAD BAY DOORS, AND ABILITY TO CRADLE AND LATCH RMS ARM
WITHOUT AN EVA.
REFERENCES:
m
w
w
C-21
I
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
142 ABORT:
ITEM:
FAILURE MODE:
MDM PFI,PF2
ERRONEOUS OUTPUT TO GPC
HDW/FUNC
3/IR
3/3
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)5)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PAYLOAD FORWARD MDM (PFI..2)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/3 TAL:
ONORBIT: 3/1R AOA:
DEORBIT: 3/3 ATO:
LANDING/SAFING: 3/3
HDW/FUNC
3/3
3/3
3/3
3/3
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION: AV BAY 1,2
PART NUMBER: MC615-0004-6710,5710
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS/BSS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SWIGNORES THAT DATA. SYSTEM SOFTWARE BYPASSES MDM AFTER 2ND
CONSECUTIVE COMMFAULT, AND DISPLAYS FAULT MSG ON CRTS. PORT
MODING MAY NOT RECOVER MDM. IF ALL REDUNDANCY FAILS, LOSE
ABILITY TO RELEASE, OPEN, CLOSE, AND LATCH PAYLOAD BAY DOORS, AND
ABILITY TO CRADLE AND LATCH RMS ARM WITHOUT AN EVA.
REFERENCES:
m
l
z
m
m
M
z
I
U
J
M
I
mI
C-22
m
m
w
m
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 143 ABORT:
HDW/FtrNC
3/IR
3/3
ITEM:
FAILURE MODE:
MDM PFI,PF2ERRONEOUS OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)2)3)4)s)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PAYLOAD FORWARD MDM (PFI..2)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/3
LIFTOFF: 3/3 TAL: 3/3
ONORBIT: 3/IR AOA: 3/3
DEORBIT: 3/3 ATO: 3/3
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAY 1,2
PART NUMBER: MC615-0004-6710,5710
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS/BSS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORDPROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT PF MDMS.
DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK SIGNALS. IF
ALL REDUNDANCY FAILS, LOSE ABILITY TO RELEASE, OPEN, CLOSE, AND
LATCH PAYLOAD BAY DOORS, AND ABILITY TO CRADLE AND LATCH RMS ARM
WITHOUT AN EVA.
REFERENCES:
C-23
J
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 144 ABORT:
ITEM:
FAILURE MODE:MDM PF1,PF2PREMATURE OPERATION TO GPC
HDW/FUNC3/1R3/3
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)2)3)4)s)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PAYLOAD FORWARD MDM (PF1..2)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/3LIFTOFF: 3/3 TAL: 3/3
ONORBIT: 3/IR AOA: 3/3
DEORBIT: 3/3 ATO: 3/3
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION: AV BAY l, 2PART NUMBER: MC615-0004-6710,5710
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE :THIS FAILURE ON EITHER PORT CAN INTERFERE WITH FCOS/BSS RETURNING
DATA FROM OTHER PF MDM AND CAUSE GOOD MDM TO BE BYPASSED. PORTMODING WILL NOT FIX A BLABBING MDM. POWER CYCLING MAY RESET
ELECTRONICS, BUT WILL NOT ALWAYS STOP PREMATURE OPERATIONS. IF
ALL REDUNDANCY FAILS, LOSE ABILITY TO RELEASE, OPEN, CLOSE, ANDLATCH PAYLOAD BAY DOORS, AND ABILITY TO CRADLE AND LATCH RMS ARM
WITHOUT AN EVA.
REFERENCES:
m
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C-24
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
145 ABORT:
HDW/FUNC
3/IR3/3
ITEM:
FAILURE MODE:
MDM PF1,PF2PREMATURE OPERATION TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
S)
6)
7)
8)9)
DPS
MULTI PLEXER- DEMULTI PLEXERS (MDM)
PAYLOAD FORWARD MDM (PFI.. 2)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/3
LIFTOFF: 3/3 TAL: 3/3
ONORBIT: 3/IR AOA: 3/3
DEORBIT: 3/3 ATO: 3/3
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,2
MC615-0004-6710,5710
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS/BSS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORDPROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT PF MDMS.
DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK SIGNALS. IF
ALL REDUNDANCY FAILS, LOSE ABILITY TO RELEASE, OPEN, CLOSE, AND
LATCH PAYLOAD BAY DOORS, AND ABILITY TO CRADLE AND LATCH RMS ARM
WITHOUT AN EVA.
REFERENCES:
w
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C-25
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 146 ABORT:
HDW/FUNC
3/1R
3/3
ITEM: MDM PFI,PF2FAILURE MODE: SELECTED ALL CHANNELS WRONG
LEAD ANALYST: W. A. HAUFLER
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)v)8)9)
SUBSYS LEAD: B. ROBB
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PAYLOAD FORWARD MDM (PFI..2)
CRITICALITIES
HDW/FUNC ABORTFLIGHT PHASE
PRELAUNCH: 3/2R
LIFTOFF: 3/3
ONORBIT: 3/1RDEORBIT: 3/3
LANDING/SAFING: 3/3
RTLS:
TAL:
AOA:ATO:
HDW/FUNC3/3
3/3
3/33/3
REDUNDANCY SCREENS: A [ 1 ] B [ P ] c[P]
LOCATION: AV BAY 1,2
PART NUMBER: MC615-0004-6710,5710
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:THE GPC'S FCOS AND THE LRUS WOULD REJECT ALL DATA FROM THAT MDM
EXCEPT ANY DATA THAT HAPPENED TO BE IN THE SAME FORMAT AS THEEXPECTED DATA. REDUNDANCY MGT. SOON DETECTS AND BYPASSES THAT
MDM, AND THE EFFECTS OF WRONG DATA INPUT OR OUTPUT IS MINIMIZED.
IF ALL REDUNDANCY FAILS, LOSE ABILITY TO RELEASE, OPEN, CLOSE,AND LATCH PAYLOAD BAY DOORS, AND ABILITY TO CRADLE AND LATCH RMSARM WITHOUT AN EVA.
REFERENCES:
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i
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z
n
mm
l
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l
w
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 147 ABORT:
HDW/FUNC
311R
3/3
ITEM:
FAILURE MODE:
MDM PFI,PF2STUCK ON A CONSTANT OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)
2)3)4)s)6)7)B)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PAYLOAD FORWARD MDM (PFI..2)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/3
LIFTOFF: 3/3 TAL: 3/3
ONORBIT: 3/IR AOA: 3/3
DEORBIT: 3/3 ATO: 3/3
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ]
LOCATION: AV BAY 1,2
PART NUMBER: MC615-0004-6710,5710
B [ P ] C [ P ]
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS/BSS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORDPROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT PF MDMS.
DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK SIGNALS. IF
ALL REDUNDANCY FAILS, LOSE ABILITY TO RELEASE, OPEN, CLOSE, AND
LATCH PAYLOAD BAY DOORS, AND ABILITY TO CRADLE AND LATCH RMS ARM
WITHOUT AN EVA.
REFERENCES:
C-27
INDEPENDENT ORBITER ASSESSMENTORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:148 ABORT:
HDW/FUNC
3/1R3/3
ITEM:
FAILURE MODE:MDM PFI,PF2FALSELY STUCK ON BUSY MODE
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)2)3)4)5)6)7)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PAYLOAD FORWARD MDM (PF1..2)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/3
LIFTOFF: 3/3 TAL: 3/3ONORBIT: 3/IR AOA: 3/3
DEORBIT: 3/3 ATO: 3/3
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION_
PART NUMBER:AV BAY 1,2
MC615-0004-6710,5710
CAUSES: VIB_TION, CORROSION, CONTAMINATION, SCU BUSY CROSS-STRAP STUCK HIGH
EFFECTS/RATIONALE:FCOS/BSS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SWIGNORES THAT DATA. SYSTEM SOFTWARE BYPASSES MDM AFTER 2ND
CONSECUTIVE COMMFAULT, AND DISPLAYS FAULT MSG ON CRTS. PORTMODING MAY NOT RECOVER MDM. IF ALL REDUNDANCY FAILS, LOSE
ABILITY TO RELEASE, OPEN, CLOSE, AND LATCH PAYLOAD BAY DOORS, ANDABILITY TO CRADLE AND LATCH RMS ARM WITHOUT AN EVA.
REFERENCES:
l
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l
I
am
I
_I
mm
M
i
l
im
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mum
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C-28 I
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w
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
180 ABORT:
HDW/FUNC
312R
/NA
ITEM:
FAILURE MODE:
MDM LF1,LA1
LOSS OF OUTPUT TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)
3)
4)
5)
6)
7)
8)
9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PRELAUNCH FORWARD & AFT MDM (LF,LA)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: /NA TAL: /NA
ONORBIT: /NA AOA: /NA
DEORBIT: /NA ATO: /NA
LANDING/SAFING: 3/2R
REDUNDANCY SCREENS: A [ 1 ]
LOCATION: AV BAY 1,6
PART NUMBER: MC615-0004-6610,5600
B [ P ] C [ P ]
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM. IF
ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITOR AND CONTROL
SYSTEMS WHILE ATTACHED.
REFERENCES:
C-29
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE : 10/03/86 HIGHEST CRITICALITY HDW/FUNCSUBSYSTEM: DPS FLIGHT : 3/2R
MDAC ID: 181 ABORT: /NA
ITEM: MDM LFI, LAIFAILURE MODE: LOSS OF OUTPUT TO LRU ........
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY :
I) DPS
2) MULTIPLEXER-DEMULTIPLEXERS (MDM) ......3) PRELAUNCH FORWARD & AFT MDM (LF,LA)
4)s)6)7)s)9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH : 3/2R RTLS : /NALIFTOFF : /NA TAL: /NA
ONORBIT : /NA AOA: /NA
DEORBIT : /NA ATO : /NALANDING/SAFING: 3/2R
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAY i, 6
PART NUMBER: MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE :Fcos DOES NOT D_RECTLY DETE_T T_S E_O_ V!_a MDM RE_ WOR_D _ _PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITORAND CONTROL SYSTEMS WHILE ATTACHED.
REFERENCES :
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 182 ABORT:
HDW/FUNC
3/2R/NA
ITEM:
FAILURE MODE:
MDM LF1,LA1
ERRONEOUS OUTPUT TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)
3)
4)
S)
6)
V)
8)
9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PRELAUNCH FORWARD & AFT MDM (LF,LA)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: /NA TAL: /NA
ONORBIT: /NA AOA: /NA
DEORBIT: /NA ATO: /NA
LANDING/SAFING: 3/2R
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:AV BAY 1,6
MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:
FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM, BUT
NOT ALLOWED DURING ASCENT UNTIL AFTER 2ND MDM FAILURE. IF ALL
REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITOR AND CONTROLSYSTEMS WHILE ATTACHED.
REFERENCES:
m C-31
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 183 ABORT:
HDW/FUNC
312R
/NA
ITEM:FAILURE MODE:
MDM LFI,LAIERRONEOUS OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)
2)3)4)5)6)
8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PRELAUNCH FORWARD & AFT-MDM°(LF,LA)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORTPRELAUNCH: 3/2R RTLS:
LIFTOFF: /NA TAL:ONORBIT: /NA AOA:
DEORBIT: /NA ATO:
_DING/SAFING: 3/2R
HDW/FUNC/NA/NA
/NA
/NA
REDUNDANCY SCREENS: A [ ! ] B [ P ] C [ P ]
LOCATION:PART _BER:
AV BAY 1,6
MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION ........
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD _
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITORAND CONTROL SYSTEMS WHILE ATTACHED.
REFERENCES:
I
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m
m
l
l
m
m
mmm
m
m
mmmm
INto
L
mm
m
W
mm
C-32 m
m
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u
m
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 184 ABORT:
HDW/FUNC
3/2R
/NA
ITEM: MDM LF1,LAI
FAILURE MODE: PREMATURE OPERATION TO GPC
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)3)4)5)6)7)s)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PRELAUNCH FORWARD & AFT MDM (LF,LA)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: /NA TAL: /NA
ONORBIT: /NA AOA: /NA
DEORBIT: /NA ATO: /NA
LANDING/SAFING: 3/2R
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,6
MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:THIS FAILURE ON EITHER PORT CAN INTERFERE WITH FCOS RETURNING
DATA FROM OTHER BTU(S) AND CAUSE GOOD BTU(S) TO BE BYPASSED.PORT MODING WILL NOT FIX A BLABBING MDM. POWER CYCLING MAY RESET
ELECTRONICS, BUT WILL NOT ALWAYS STOP PREMATURE OPERATIONS. IF
ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITOR AND CONTROL
SYSTEMS WHILE ATTACHED.
REFERENCES:
C-33
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 185 ABORT:
HDW/FUNC
3/2R
/NA
ITEM:
FAILURE MODE:MDM LFI,LA1PREMATURE OPERATION TO LRU_ _
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PRELAUNCH FORWARD & AFT MDM (LF,LA)
CRITICALITIESFLIGHT PHASE HDw/FUNC ABORT
PRELAUNCH: 3/ 2R RTLS :
LIFTOFF : /NA TAL:
ONORBIT: /NA AOA:
DEORBIT: /NA ATO:
LANDING/SAFING: 3/2R
HDW/FUNC/NA_/NA
/NA/NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAY 1,6PART NUMBER: MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORDPROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITORAND CONTROL SYSTEMS wHILE ATTACHED.
REFERENCES:
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mm
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m
mm
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C-34
m
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 186 ABORT:
HDW/FUNC
312R
/NA
ITEM: MDM LF1,LAI
FAILURE MODE: SELECTED ALL CHANNELS WRONG
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)3)4)s)6)v)8)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PRELAUNCH FORWARD & AFT MDM (LF,LA)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: /NA TAL: /NA
ONORBIT: /NA AOA: /NA
DEORBIT: /NA ATO: /NA
LANDING/SAFING: 3/2R
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,6
MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:THE GPC'S FCOS AND THE LRUS WOULD REJECT ALL DATA FROM THAT MDM
EXCEPT ANY DATA THAT HAPPENED TO BE IN THE SAME FORMAT AS THE
EXPECTED DATA. REDUNDANCY MGT. SOON DETECTS AND BYPASSES THAT
MDM, AND THE EFFECTS OF WRONG DATA INPUT OR OUTPUT IS MINIMIZED.
IF ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITOR AND
CONTROL SYSTEMS WHILE ATTACHED.
REFERENCES:
C-35
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: i0/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 187 ABORT:
HDW/FUNC
3/2R/NA
ITEM:
FAILURE MODE:MDM LFI,LA!
STUCK ON A CONSTANT OUTPUT TO LRU
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)v)s)9)
DPS
MULTIPLEXER-DEMULTIPLEXERS (MDM)
PRELAUNCH FORWARD & AFT MDM (LF,LA)
CRITICALiTIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: /NA TAL: /NA
ONORBIT: /NA AOA: /NA
DEORBIT: /NA ATO: /NA
LANDING/SAFING: 3/2R
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:AV BAY 1,6
MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION
EFFECTS/RATIONALE:FCOS DOES NOT DIRECTLY DETECT THIS ERROR VIA MDM RETURN WORD
PROCESSING. FAULT TOLERANCE DEPENDS ON REDUNDANT STRINGS TO
VOTING LRUS. DETECTION DEPENDS ON SEPARATE, REDUNDANT FEEDBACK
SIGNALS. IF ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITORAND CONTROL SYSTEMSWHILE ATTACHED.
REFERENCES:
l
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mi
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C-36
B -
m
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DATE:
SUBSYSTEM:
MDAC ID:
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
188 ABORT:
HDW/FUNC
3/2 /NA
ITEM:
FAILURE MODE:
MDM LF1,LAIFALSELY STUCK ON BUSY MODE
LEAD ANALYST: W. A. HAUFLER SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)4)s)6)T)s)9)
DPS
MULTI PLEXER- DEMULTI PLEXERS (MDM)
PRELAUNCH FORWARD & AFT MDM (LF,LA)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: /NA TAL: /NA
ONORBIT: /NA AOA: /NA
DEORBIT: /NA ATO: /NA
LANDING/SAFING: 3/2R
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 1,6
MC615-0004-6610,5600
CAUSES: VIBRATION, CORROSION, CONTAMINATION, SCU BUSY CROSS-
STRAP STUCK HIGH
EFFECTS/RATIONALE:FCOS SETS COMMFAULT FLAG FOR THAT DATA. APPLICATION SW IGNORES
THAT DATA. FCOS BYPASSES MDM AFTER 2ND CONSECUTIVE COMMFAULT,
AND DISPLAYS FAULT MSG ON CRTS. PORT MODING MAY RECOVER MDM. IF
ALL REDUNDANCY FAILS, LOSE ABILITY OF GSE TO MONITOR AND CONTROL
SYSTEMS WHILE ATTACHED.
REFERENCES:
m
C-37
DATE:
SUBSYSTEM:MDAC ID:
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
201 ABORT:
HDW/FUNC3/1R3/1R
ITEM:FAILURE MODE:
INPUT/OUTPUT pROCE SSOR (!oP)LOSS OF OUTPUT
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)3)4)s)6)7)8)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
INPUT/OUTPUT PROCESSOR (IOP)_i_
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IRLIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/1R
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAYS
PART NUMBER:
CAUSES: MIA FAILS TO OUTPUT TO DATA BUS DUE TO PIECE/PART
FAILURE FROM CONTAMINATION OR MECHANICAL, THERMAL, OR ELECTRICAL
OVERSTRESS, OR POWER FAILURE
EFFECTS/RATIONALE:LOSS OF A BUS-COMMANDING MIA RESULTS IN LOSS OF A GPC'S ABILITY
TO COMMUNICATE OVER THAT BUS, ATTACHED BUS TERMINAL UNITS
(BTU'S), AND ALL INPUTS AND OUTPUTS CONNECTED TO THOSE BTU'S.DYNAMIC FLIGHT PHASES, WHERE A SINGLE BTU CONTROLS AN ACTUATOR,THE CREW WOULD HAVE TO MANUALLY INTERVENE ON A SINGLE FAILURE,
AND SWITCHING TRANSIENTS COULD ARISE. LOSS OF ALL REDUNDANCY
WOULD CAUSE LOSS OF VEHICLE CONTROL.
IN
REFERENCES: JSC 18820, JSC ii174, JSC 12770
I
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mR
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z
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C-38 m
uu
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L
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITY
DPS FLIGHT:
202 ABORT:
HDW/FUNC
3/mR3/IR
ITEM:
FAILURE MODE:
INPUT/OUTPUT PROCESSOR (IOP)
ERRATIC/ERRONEOUS OUTPUT
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)2)3)4)5)6)7)s)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
INPUT/OUTPUT PROCESSOR (IOP)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAYS
CAUSES: COMPONENT FAILURE DUE TO CONTAMINATION OR MECHANICAL,
THERMAL, OR ELECTRICAL OVERSTRESS IN MIA, ALU, MUX, LOCAL STORE,
OR MEMORY
EFFECTS/RATIONALE:CRITICAL GPC OUTPUTS ARE VALIDATED BY SUMWORD COMPARISON;
HOWEVER, ERRORS ARE DOWNLINKED AND LOGGED, BUT NOT CORRECTED.
MDM/ACTUATOR HARDWARE CANCELS THE EFFECTS OF AN ERRONEOUS OUTPUT
FROM A SINGLE CHANNEL BY "FORCE FIGHTING", BUT MULTIPLE FAILURES
DURING CRITICAL FLIGHT PHASES WOULD LIKELY RESULT IN LOSS OF
VEHICLE/LIFE.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
w
C-39
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 203 ABORT:
HDW/FUNC
2/IR
2/1R
ITEM:FAILURE MODE:
INPUT/OUTPUTPROCESSOR (IOP)PREMATURE OPERATION_
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)7)8)9)
DPS
GENERAL PURPOSE COMPUTER (GPC) ......INPUT/OUTPUT PROCESSOR (IOP)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORTPRELAUNCH: 3/3 RTLS:
LIFTOFF: 2/!R TAL:
ONORBIT: 3/2R AOA:DEORBIT: 2/IR ATO:
LANDING/SAFING: 2/IR
HDW/FUNC
2/IR3/1R3/1R_
7
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION: AV BAYS
PART NUMBER:
CAUSES: CONTROL MONITOR, CHANNEL CONTROL, MSC, OR M"ICROCODESTORE FAILURE RESULTS IN INVALID EXECUTION OF PROGRAM. CAUSED BY
PIECE/PART FAILURE.
EFFECTS/RATIONALE:PREMATURE ISSUANCE OF CRITICAL OUTPUTS IS DETECTED BY OTHER GPC'S
IN THE REDUNDANT SET. GPC FAILS TO SYNC AND STRINGS ARE BYPASSEDBY OTHER GPC'S. FAULTY COMMANDS ARE STILL PASSED TO THE ACTUATOR
BY FAILED GPC. PREMATURE COMMANDS TO ACTUATORS DURING DYNAMIC
FLIGHT PHASES WOULD LIKELY RESULT IN LOSS OF VEHICLE/LIFE, IFACTUATOR REDUNDANCY WAS LOST OR IF SIMULTANEOUS LOSS OF TWOOUTPUT CHANNELS.
REFERENCES: JSC 18820, JSC ii174, JSC 12770
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 204 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
INPUT/OUTPUT PROCESSOR (IOP)
ERRONEOUS INPUT
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)7)8)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
INPUT/OUTPUT PROCESSOR (IOP)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:
AV BAYS
CAUSES: COMPONENT FAILURE DUE TO CONTAMINATION OR MECHANICAL,
THERMAL, OR ELECTRICAL OVERSTRESS IN MIA, ALU, MUX, LOCAL STORE,
MEMORY, OR DMA QUEUE
EFFECTS/RATIONALE:
CRITICAL GPC/IOP INPUTS ARE VALIDATED THRU PARITY CHECKING.RECURRING INPUT ERRORS RESULT IN EITHER GPC "FAIL-TO-SYNC"
BRINGING DOWN AN ERRING GPC, OR IGNORING INPUTS FROM AN ERRING
MDM VIA A GPC MASK. ERRONEOUS INPUTS, IF PROPAGATED THROUGH THE
GPC, COULD RESULT IN ERRONEOUS COMMAND OUTPUTS AND LOSS OF
VEHICLE/LIFE, IF COMPLETE FUNCTION WAS LOST.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
w
C-41
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 205 ABORT:
HDW/FUNC
3/1R3/iR
ITEM:
FAILURE MODE:CENTRAL PROCESSING UNIT (CPU)LOSS OF OUTPUT
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)s)6)7)8)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/3 RTLS: 3/1R
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/iR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS:
LOCATION: AV BAYS
PART NUMBER:
A [ 1 ] B [ P ] C [ P ]
CAUSES: CPU FAILS TO FUNCTION DUE TO LOSS OF POWER OR FAILURE OF
MEMORY TIMING PAGE
EFFECTS/RATIONALE:
IN DYNAMIC FLIGHT P_SES WHERE REDUNDANT SET (RS) IS OPERATING,
OTHER GPC'S RECOGNIZE GPC FAILING TO SYNC AND ISSUE FAIL VOTES
AGAINST IT. THE FAILING GPC'S VOTING LOGIC THEN REMOVES IT FROM
THE RS. FOUR RS GPC'S CONT_O_U_IT_CAL FLIGHT FUNCTIONS; IF AT
LEAST THREE ARE LOST, THE 5TH GPC (BACKUP FLIGHT COMPUTER, BFS)
IS ENGAGED. LOSS OF BFS WOULD RESULT IN LOSS OF VEHICLE/LIFE.
REFERENCES: JSC 18820, JSC ii174, JSC 12770
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 206 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
CENTRAL PROCESSING UNIT (CPU)
ERRONEOUS/ERRATIC OUTPUT
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
5)
6)
7)
S)
9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/1R
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/3 AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAYS
CAUSES: CPU OUTPUTS INVALID DATA TO IOP DUE TO MEMORY PARITY
ERROR, OR FAILURE OF MASTER BUS CONTROL, ALU, DATA FLOW MUX, ORLOCAL STORE
EFFECTS/RATIONALE:
CRITICAL GPC OUTPUTS ARE VALIDATED BY SUMWORD COMPARISON TO
OUTPUTS FROM REDUNDANT GPC'S; HOWEVER, DETECTED ERRORS ARE MERELY
LOGGED AND DOWNLINKED WITHOUT CORRECTIVE ACTION. INVALID COMMAND
OUTPUTS ARE PASSED THROUGH BUS TERMINAL UNITS (BTU'S) TO
ACTUATORS WHICH "FORCE FIGHT" THE REDUNDANT COMMANDS IN ORDER TO
VOTE OUT THE ERRONEOUS COMMAND. LOSS OF MORE THAN ONE OUTPUT
CHANNEL TO THE SAME ACTUATOR WOULD REQUIRE CREW INTERVENTION,
POSSIBLY CAUSING UNSTABLE SWITCHOVER TRANSIENTS.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
mC-43
INDEPENDENT ORBITER ASSESSMENTORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:MDAC ID:
10/03/86 HIGHEST CRITICALITYDPs FLIGHT:
207 ABORT:
HDW/FUNC3/IR
ITEM:
FAILURE MODE:
CENTRAL PROCESSING UNIT (CPU)
DELAYED�PREMATURE�INADVERTENT OPERATION
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)5)6)T)8)9)
DPS
GENERAL PURPOSE COMPUTER (GPC) .......
CENTRAL PROCESSING UNIT (CPU)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR _LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/3 AOA: 3/IR
DEORBIT: 3/1R ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAYS
PART NUMBER:
CAUSES: CPU ATTEMPTS TO OUTPUT DATA AT INAPPROPRIATETIME DuE To
PROCESSOR SLOW-DOWN WHILE SERVICING RECURRING I/O ERRORS, FAILURE
OF INTERRUPT LOGIC, OR INTERMITTENCE IN TIMING PAGE.
EFFECTS/RATIONALE:REDUNDANT SET GPC'S SYNC UP BY WAITING FOR SYNC POINT MESSAGESFROM OTHER GPC' S TO iNDIC-ATE COMPLETION OF I--DENTIC_ OPEP_ATIONS.
EXCESSIVE PROCESSOR LOAD COULD REQUIRE ALL GPC'S TO WAIT
EXCESSIVELY, BUT EACH GPC WOULD RECOGNIZE THE SLOW DOWN AND ISSUE
A FAIL-TO-SYNC VOTE, AND THE SLOW GPC'S VOTING LOGIC WOULD REMOVEIT FROM_THE RS. IF PERFORMANCE OF ALL GPC'S WAS DEGRADED DURING
DYNAMIC FLIGHT PHASES, VEHICLE INSTABILITY COULD OCCUR UNLESS
CREW TOOK CONTROL.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 208 ABORT:
HDW/FUNC
2/1R2/IR
ITEM:
FAILURE MODE:
CENTRAL PROCESSING UNIT (CPU)
INADVERTENT OPERATION
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
5)
6)
7)
8)
9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/3 RTLS: 2/IR
LIFTOFF: 2/IR TAL: 2/IR
ONORBIT: 3/3 AOA: 2/IR
DEORBIT: 2/IR ATO: 2/1R
LANDING/SAFING: 2/IR
REDUNDANCY SCREENS: A [ 1 ] SIP] C[P]
LOCATION:
PART NUMBER:
AV BAYS
CAUSES: CPU ATTEMPTS TO OUTPUT DATA ON INCORRECT DATA BUS DUE TO
ERRORS IN MEMORY LOCATIONS CONTAINING CONFIGURATION OR BUS-
STRINGING PARAMETERS.
EFFECTS/RATIONALE:
LOSS OF MEMORY IN BUS ASSIGNMENT TABLE (NBAT) COULD RESULT IN A
GPC ATTEMPTING TO COMMAND A DATA BUS COMMANDED BY ANOTHER GPC.
BOTH EXAMINE THEIR RESPECTIVE NBAT AND ASSUME NO ERROR CONDITION,
AND CONTINUE TRANSMISSION ON THAT SAME BUS. THIS WOULD CAUSE ALL
DATA ON THAT BUS TO BE ERRONEOUS. FURTHERMORE, IDLE BUS IS
CREATED AND 2 COMMAND PATHS ARE LOST. POSSIBLE TO OUTVOTE GOOD
COMMANDS: LOSS OF VEHICLE/LIFE.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
C-45
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WO_SHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 209 ABORT:
HDW/FUNC
3/33/3
ITEM:FAILURE MODE:
CPU POWERSWITCHFAILS CLOSED
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)7)s)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)CPU POWER SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNCPRELAUNCH: 3/3 RTLS: 3/3 _i _
LIFTOFF: 3/3 TAL: 3/3 :_
ONORBIT: 3/3 AOA: 3/3
DEORBIT: 3/3 ATO: 3/3_LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: PANEL 06
PART NUMBER:
CAUSES: CPU POWER SWITCH IS STUCK IN THE "ON" POSITION DUE TO
CONTAMINATION
EFFECTS2RAT_ALE:FLIGHT RULES DICTATE THAT THE CREW SHOULD POWER OFF ANY GPC WHICH
HAS RECURRING ERRORS DURING DYNAMIC FLIGHT PHASES, AS SOON AS
POSSIBLE TO AVOID ERRONEOUS OUTPUTS BEING SENT TO ACTUATORS. IFTHE CPU POWER SWITCH WERE STUCK IN THE-_'O_SiTiON AND ANOTHER
GPC BEGAN SENDING ERRONEOUS DATA, THE ACTUATORS COUL_NOT VOTE ........OUT THE ERRONE0_S _Q_NDS AND THEIICRE_ WOULD NEED TO T_KE MANUAL
CONTROL. _ _z_ ? i _ _ : _ :::_
REFERENCES: JSC 18820, JSC 11174, JSC 12770
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DATE:
SUBSYSTEM:
MDAC ID:
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
lo/o3186DPS
210
HIGHEST CRITICALITY
FLIGHT:
ABORT:
HDWIFUNC3/ZR3/1R
ITEM:
FAILURE MODE:
GPC MODE SWITCH
FAILS CLOSED
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
S)
6)
7)
8)
9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)
GPC MODE SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/3 RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/1R
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
PANEL 06
CAUSES: CPU MODE SWITCH IS STUCK IN THE "HALT" OR "STANDBY"
POSITION DUE TO CONTAMINATION
EFFECTS/RATIONALE:IF THE MODE SWITCH FOR A GPC WERE STUCK IN A NON-RUN POSITION THE
GPC WOULD IN EFFECT BE DISABLED, SIMILAR TO FAILING TO HALT. THE
REMAINING GPC'S WOULD IGNORE THIS GPC, AND THE GPC WOULD NOT BE
AVAILABLE AS A BACKUP OR REDUNDANT MEMBER. IF ALL GPC'S WERE
STUCK IN THE STANDBY MODE, THE CREW COULD NOT PERFORM CRITICAL
FLIGHT CONTROL FUNCTIONS.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
w
C-47
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 211 ABORT:
HDW/FUNC
S/IRS/ZR
ITEM:
FAILURE MODE:
GPC OUTPUT SWITCH
FAILS CLOSED
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)s)4)s)6)7)8)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)
GPC OUTPUT SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/3 RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/iR
ONORBIT: 3/3 AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION: PANEL 06
PART NUMBER:
CAUSES: CPU OUTPUT SWITCH IS STUCK IN THE "TERMINATE" OR
"BACKUP" POSITION DUE TO CONTAMINATION
EFFECTS/RAT!ONALE, _L_ _ _i!_ _ iiIF THE OUTPUT SWITCH WERE STUCK IN THE "TERMINATE" POSITION, THIS
WOULD HAVE THE SAME EFFECT OF DISABLING THE GPC'S OUTPUT; ALL
SWITCHES IN THIS POSITION WOULD CAUSE LOSS OF VEHICLE CONTROL.
IF THE SWfTCH-W'2_ES_TUCK -_iN THE "BAcKuP ''_-PO_TION THIS GPC WOULD
ONLY BE AVAILABLE AS BFS. IF ALL SWITCHES IN "BACKUP" GPC 5
WOULD BE BAC_P WHEN ENGAGED.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
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INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
212 ABORT:
HDW/FUNC
3/33/3
ITEM:
FAILURE MODE:
IPL SOURCE SWITCH
FAILS OPEN
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)7)s)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)
MMU INITIAL PROGRAM LOAD (IPL) SOURCE SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNCPRELAUNCH: 3/3 RTLS: 3/3
LIFTOFF: 3/3 TAL: 3/3
ONORBIT: 3/3 AOA: 3/3DEORBIT: 3/3 ATO: 3/3
LANDING/SAFING: 3/3
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:
PANEL 06
CAUSES: IPL SELECTOR SWITCH IS SHORTED OR POWER SOURCE IS LOST
DUE TO CONTAMINATION
EFFECTS/RATIONALE:IPL SOURCE SWITCH IS USED AT PRE-LAUNCH TO INITIALIZE GPC'S.
THIS FAILURE COULD CAUSE LOSS OF A MISSION OPPORTUNITY DUE TOLAUNCH DELAY. DURING FLIGHT THE GPC'S ARE NOT TYPICALLY RE-
IPL'ED, EVEN THOUGH THE MMU IS USED TO RETRIEVE NEW MEMORY
OVERLAYS (AS OPPOSED TO THE IPL LOADING THE ENTIRE SYSTEM
SOFTWARE, INCLUDING MCDS INITIALIZATION).
REFERENCES: JSC 18820, JSC 11174, JSC 12770
n C-49
m
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 213 ABORT:
HDW/FUNC
3/IR
3/IR
ITEM:
FAILURE MODE:
GPC POWER SWITCH
FAILS OPEN
LEAD ANALYST: T. B. CRIBBS SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)?)8)9)
DPS
GENERAL PURPOSE COMPUTER (GPC)
CENTRAL PROCESSING UNIT (CPU)GPC POWER SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/3 RTLS: 3/IRLI FTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/2R AOA: 3/IR
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/IR ........ " '
REDUNDANCY SCREENS: A [ 1 ]
LOCATION: PANEL 06PART NUMBER:
B [ P ] C [ P ]
CAUSES: CPU POWER SWITCH IS STUCK IN "OFF" POSITION, OR GPC _ _
POWER IS LOST
EFFECTS/RATIONALE: ....... :IF THE GPC POWER SWITCH WERE STUCK IN THE "OFF" POSITION, THE GPC
COULD NOT FUNCTION, SAME AS CPU LOSS OF OUTPUT.
REFERENCES: JSC 18820, JSC 11174, JSC 12770
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II
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITY
DPS FLIGHT:
300 ABORT:
HDW/FUNC
311R3/IR
ITEM:
FAILURE MODE:
KEYBOARD SWITCH
OPEN/CLOSED
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)2)3)4)5)6)7)s)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
KEYBOARD
SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/IR TAL:
ONORBIT: 3/IR AOA:
DEORBIT: 3/IR ATO:
LANDING/SAFING: 3/IR
HDW/FUNC
3/IR3/IR3/IR3/IR
REDUNDANCY SCREENS: A [ 1 ] scP] C[P]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: MECHANICAL FRACTURE/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF INPUTTING COMMAND CAPABILITY. REDUNDANT HARDWARE WOULD
NOT BE ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
C-51
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:MDAC ID: 301 ABORT:
HDW/FUNC3/IR3/IR
ITEM: X/Y DEFLECTION AMPLIFIERS
FAILURE MODE: NO OUTPUT/ERRONEOUS/ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)3)4)s)6)v)s)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)DISPLAY UNIT
X/Y DEFLECTION AMPLIFIERS
FLIGHT PHASE
PRELAUNCH: 3/2R
LIFTOFF: 3/IR
ONORBIT: 3/IR
DEORBIT: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS:
C_iTIC_ITIESHDW/_NC ABORT HDW/FUNC
RTLS: 3AIR ii_
TAL: 3/IRAOA: 3/!R
ATO: 3/iR
A [ 1 ] B [ P ] C [ P ] :_ :.
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: TEMPERATURE STRESS/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
Hmm
|
ms
a
I
i
[]
m
w i
m
m
mm
m
m
m
C-52 m
m
m
w
n
w
i
w
h
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 302 ABORT:
HDW/FUNC
3/IR3/IR
ITEM:
FAILURE MODE:
VIDEO AMPLIFIER
NO OUTPUT/ERRONEOUS/ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)
2)
3)
4)
5)
6)
7)
S)
9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DISPLAY UNIT
VIDEO AMPLIFIER
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/IR TAL:
ONORBIT: 3/IR AOA:
DEORBIT: 3/1R ATO:
LANDING/SAFING: 3/IR
HDW/FUNC
3/IR
3/IR
3/IR
3/IR
REDUNDANCY SCREENS: A [ 1 ]
LOCATION: UPPER CREW AREA
PART NUMBER:
B[P] c[P]
CAUSES: TEMPERATURE STRESS/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
C-53
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 303 ABORT:
HDW/FUNC
311R
311R
ITEM:FAILURE MODE:
CATHODE-RAY TUBE
NO OUTPUT/ERRONEOUS/ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)2)3)4)s)6)
s)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DISPLAY UNITCATHODE-RAY TUBE
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/1R
LIFTOFF: 3/1R TAL: 3/1R
ONORBIT: 3/1R AOA: 3/1R
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: UPPER CREW AREA
PART NUMBER:
CAUSES: SHOCK/ TEMPERATURE STRESS/ MECHANICAL FRACTURE/
VIBRATION/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE ....LOSS OF MoNIT_GCAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY_THROUGH: : {:_
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
m
mm
I
[]
m
m
m
D
m
I
I
ms
mn
D
mm
z
M
z
I
C-54
m i
w
r-u
L_
m
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY HDW/FUNC
SUBSYSTEM: DPS FLIGHT: 3/1R
MDAC ID: 304 ABORT: 3/IR
ITEM:
FAILURE MODE:
HI AND LOW VOLTAGE POWER SUPPLIES
NO OUTPUT�ERRONEOUS�ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)
2)
3)
4)
S)
6)
V)
8)
9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DISPLAY UNIT
HIGH AND LOW (+/-5, 15, 28 & 80 VDC) VOLTAGE POWER SUPPLIES
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/IR AOA: 3/IR
DEORBIT: 3/IR ATO: 3/!R
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: MECHANICAL FRACTURES/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:
LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAIN
ENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
C-55
DATE:
SUBSYSTEM:
MDAC ID:
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
305 ABORT:
HDW/FUNC3/1R3/1R
ITEM:
FAILURE MODE:
RPC
OPEN/CLOSED/PREMATuR_OPE_ION
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
4)S)6)?)8)9)
i) DPS
2) m3LTIFUNCTIONCRT 0ZSP_Y SYSTEM (MOOs)...._3 ) DISPLAY UNIT
RPC
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IRLIFTOFF: 3/IR TAL: 3/iR
ONORBIT: 3/IR AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: UPPER CREA AREA
PART NUMBER:
CAUSES: MECH_ICAL FRACTURE/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORING cAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACC_S_BL_bURING PERIODS OF ANTi_ATE_ _ _HI_CH_ ..... _.................
ACCELERATION/DEACCELERATIONFORCES. IE. 1. LIFT-OFF THROUGH_NENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING _A_XI_TELY_-40-O_OO0_T _(°T_'4_O_MI_N ) " 'THRO'O_G_°SA-_E_'_ _i
REFERENCES:
I
I
I
I
I
I
I
mi
I
I
[]
I
I
iI
___ igm
i iI _"
i
C-56
i --
w
m
m
L_
w
=
k_.
= :
=
w
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 306 ABORT:
HDW/FUNC3/IR3/IR
ITEM:
FAILURE MODE:
MEMORY
NO OUTPUT/ERRONEOUS/ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
s)6)v)8)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DEU
MEMORY
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/1R
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/IR AOA: 3/IR
DEORBIT: 3/IR ATO: 3/1R
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
w C-57
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 307 ABORT:
HDW/FUNC
311R
311R
ITEM: KEYBOARD ADAPTER
FAILURE MODE: NO OUTPUT/E--RRO-NEOUS/ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HiE_CHY:
i) DPS2) MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
3) DEU4) KEYBOARD ADAPTER
s)6)7)8)9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNCPRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/1R TAL: 3/IR
ONORBIT: 3/IR AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IRLANDING/SAFING: 3/1R
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF INPUTTING COMMAND CAPABILITY. REDUNDANT HARDWARE WOULDNOT BE ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. I. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
u
m
mm
U
mm
I
B
mm
a
wJ
i
|
m
g
u
i
m
g
m
C-58 I
m
r
w
z
u
_===
L
w
mmm
n
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 308 ABORT:
HDW/FUNC
3/IR3/IR
ITEM:
FAILURE MODE:
SYMBOL GENERATOR
NO OUTPUT/ERRONEOUS/ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)T)8)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DEU
SYMBOL GENERATOR
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/IR AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAIN
ENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
C-59
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 309 ABORT:
HDWlFUNC3/IR3/IR
ITEM:
FAILURE MODE:
MIA
NO OUTPUT/ERRONEOUS/ERRAT_OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)3)4)5)6)7)s)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DEU
MIA
CRITICALITIES
FLIGHT PHASE HDW/Fi_NC ABORT
PRELAUNCH: 3/2R RTLS :
LIFTOFF : 3/1R TAL:
ONORBIT : 3/IR AOA:
DEORBIT : 3/IR ATO :
LANDiNG/SAFING : 3/IR
HDW/FUNC
3/IR3/IR
3/IR
3/1R
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
m
m
I
mmm
i
I
I
mmzg
z
Imm
B
l
i
ii
i
mm
i
D
I
g
C-60 mg
I
m
L
w
w
L.
m
w
i
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 310 ABORT:
HDW/FUNC
3/IR3/IR
ITEM:
FAILURE MODE:
CONTROL LOGIC
NO OUTPUT/ERRONEOUS/ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)3)4)s)6)v)
9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DEU
CONTROL LOGIC
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: 3/IR AOA: 3/IR
DEORBIT: 3/IR ATO: 3/IR
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P] C[P]
LOCATION: UPPER CREW AREA
PART NUMBER:
CAUSES: CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
C-61
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 311 ABORT:
HDW/FUNC
3/IR
3/IR
ITEM:
FAILURE MODE:
POWER SUPPLIES
NO OUTPUT�ERRONEOUS�ERRATIC OUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
s)6)7)8)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DEU
POWER SUPPLIES (+/-5, 12 & 15 VDC)
FLIGHT PHASE
PRELAUNCH:
LIFTOFF:
ONORBIT:
DEORBIT:
LANDING/SAFING:
CRITICALITIESHDW/FUNC
3/2R3/IR3/IR3/1R3/IR
ABORT
RTLS:
TAL:
AOA:
ATO:
HDW/FUNC
3/IR311R3/IR3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF MONITORINg CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. I. LIFT-OFF THROUGH MAINENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
D
mB
U
mm
Z
U
m
g
U
= im
mm
Q
mR
g
g
C-62 B
u
=
w
n
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 312 ABORT:
HDW/FUNC
311R
3/IR
ITEM:
FAILURE MODE:
RPC
OPEN/CLOSED/PREMATURE OPERATION
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I) DPS
2) MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
3 ) DEU
4 ) RPC
s)6)T)s)9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/IR TAL:
ONORBIT: 3/IR AOA:
DEORBIT: 3/IR ATO:
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ]
HDW/FUNC3/IR3/IR3/IR3/IR
B[P] C[P3
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES:
DEBRIS
TEMPERATURE STRESS/ MECHANICAL FRACTURE/ CONTAMINATION/
EFFECTS/RATIONALE:LOSS OF MONITORING CAPABILITY. REDUNDANT HARDWARE WOULD NOT BE
ACCESSIBLE DURING PERIODS OF ANTICIPATED HIGH
ACCELERATION/DEACCELERATION FORCES. IE. i. LIFT-OFF THROUGH MAIN
ENGINE CUT-OFF - APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH
SAFEING -APPROXIMATELY 400,000FT (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
c-63 C- <
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
313 ABORT:
HDW/FUNC3/33/3
ITEM:
FAILURE MODE:
LOAD SWITCH
OPEN/CLOSED/PREMATURE OPERATION
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)
2)3)4)5)6)T)8)9)
DPSMULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DEU
LOAD SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC
PRELAUNCH: 3/3LIFTO?F: 3/3
ONORBIT: 3/3
DEORBIT: 3/3
LANDING/SAFING: 3/3
ABORTRTLS:
TAL:
AOA:ATO:
HDW/FUNC313_.3/3
3/3
3/3
REDUNDANCY SCREENS: A [ 1 ]
LOCATION: UPPER CREW AREA
PART NUMBER:
B [ P ] c[P]
CAUSES: MECHANICAL FRACTURE/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:DEUS ARE NOT NORMALLY RELOADED DURING A MISSION.NEEDED.
SWITCH IS NOT
REFERENCES:
n
[]
J
z
mm
mmm
l
|
l
[]
[]
!
E
m
m
z
m
C-64 m
I
w
w
i
L
5_
W
w
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 314 ABORT:
ITEM:
FAILURE MODE:
FUNCTION SWITCH
OPEN�CLOSED�PREMATURE OPERATION
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
i)
2)
3)
4)
S)
6)
V)
8)
9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DEU
FUNCTION SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/IR TAL:
ONORBIT: 3/IR AOA:
DEORBIT: 3/IR ATO:
LANDING/SAFING: 3/IR
REDUNDANCY SCREENS: A [ 1 ] B[P]
HDW/FUNC
3/IR3/IR3/IR3/IR
c[P]
LOCATION:
PART NUMBER:
UPPER CREW AREA
CAUSES: MECHANICAL FRACTURE/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:IMPROPER MAJOR FUNCTION IDENTIFICATION.
HDW/FUNC
3/IR
3/IR
REFERENCES:
w
C-65
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 315 ABORT:
HDW/FUNC
3/IR
3/IR
ITEM:
FAILURE MODE:
DATA BUS COUPLER (DBC)
OPEN/SHORT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)S)
6)
V)8)9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DBC
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:LIFTOFF: 3/IR TAL:
ONORBIT: 3/IR AOA:DEORBIT: 3/IR ATO:
LANDING/SAFING: 3/IR
HDW/FUNC
3/1R
3/1R3/1R3/IR
REDUNDANCY SCREENS: A [ 1 ]
LOCATION: ALL AV BAYS
PART NUMBER:
B[P] c[P]
CAUSES: MECHANICAL FRACTURE/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:LOSS OF DATA BUS. REDUNDANT HARDWARE WOULD NOT BE ACCESSIBLE
DURING PERIODS OF ANTICIPATED HIGH ACCELERATION/DEACCELERATIONFORCES. IE. i. LIFT-OFF THROUGH MAIN ENGINE CUT-OFF -
APPROXIMATELY 8 MIN 40 SEC; 2. ENTRY THROUGH SAFEING -
APPROXIMATELY 400,000_T (TD -40 MIN) THROUGH SAFEING.
REFERENCES:
mm
i
,,m
U
I
i
m
I
i
I
m
m,,
mmmm
Iii
m
B
i
I
C-66 B
=
m
m
m
rw
m
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 316 ABORT:
ITEM:
FAILURE MODE:
DBIA
OPEN/SHORT/ERRONEOUS/ERRATIC oUTPUT
LEAD ANALYST: H J LOWERY SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
S)
6)
V)
8)
9)
DPS
MULTIFUNCTION CRT DISPLAY SYSTEM (MCDS)
DBIA
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/2R TAL:
ONORBIT: /NA AOA:
DEORBIT: /NA ATO:
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [NA ]
HDW/FUNC
3/2R/NA
/NA
/NA
c[P]
LOCATION:
PART NUMBER:
AV BAY 5
CAUSES: MECHANICAL FRACTURE/ CONTAMINATION/ DEBRIS
EFFECTS/RATIONALE:
LOSS OF ONE COMMAND/DATA PATH.
REFERENCES:
HDW/FUNC
3/2R
/NA
m
w
C-67
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:MDAC ID: 400 ABORT:
HDW/FUNC3/2R
3/2R
ITEM:
FAILURE MODE:
TAPE TRANSPORT MECHANISM
LOSS OF OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)s)6)v)8)9)
DPS
MASS MEMORY UNITS (MMU)
TAPE TRANSPORT MECHANISM
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA _LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA _
REDUNDANCY SCREENS: A [ 2 ]
LOCATION: AV BAY 1,2PART NUMBER: MC 615-0005
B [ P ] C [ P ]
CAUSES: WORN TAPE OR FOREIGN MATTER ON TAPE, MOTOR FAILURE (WORN
BRUSHES, ETC.), WORN HEADS, FAILURE OF NEGATOR SPRING CAUSINGTAPE SLIPPAGE DUE TO INCORRECT TENSION.
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
±
mI
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m
g
!
[]
m
iB
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m
iI
i
m
m
g
I
I
C-68D
i
w
mm
w
m
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 401 ABORT:
HDW/FUNC3/2R3/2R
ITEM:
FAILURE MODE:
TAPE TRANSPORT MECHANISM
ERRONEOUS OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
S)
6)
V)
8)
9)
DPS
MASS MEMORY UNITS (MMU)
TAPE TRANSPORT MECHANISM
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 2 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,2
MC 615-0005
CAUSES: WORN TAPE OR FOREIGN MATTER ON TAPE, TAPE SLIPPAGE DUE
TO INCORRECT TENSION.
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
r_
m
C-69
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 402 ABORT:
HDW/FUNC3/2R3/2R
ITEM:
FAILURE MODE:
READ ELECTRONICSLOSS OF OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)2)3)4)5)6)7)8)9)
DPS
MASS MEMORY UNITS (MMU)READ ELECTRONICS
FLIGHT PHASE HDW/FUNC
PRELAUNCH: 3/2RLI-FTOFF: 3/2R
ONORBIT: 3/2RDEORBIT: /NA
LANDING/SAFING: /NA
REDUNDANCY SCREENS:
CRITICALITIES
ABORT
RTLS:TAL:
AOA:
ATO:
A [ 2 ]
HDW/FUNC
/NA
3/2R312R312R_
B[P] C[P]
LOCATION:PART NUMBER:
AV BAY 1,2MC 615-0005
CAUSES: _ ELECT_ICALFAILURE _ ::_!__
EFFECTS/RATIONALE:IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
I
m
mm
z[]
B
m
m
mm
i
[]
[]
mm
u
m :
mm
C-70z :
m
|
m
w
wmm
m
l
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 403 ABORT:
ITEM:
FAILURE MODE:
READ ELECTRONICS
ERRONEOUS OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
S)
4)
S)
6)
7)
S)
9)
DPS
MASS MEMORY UNITS (MMU)READ ELECTRONICS
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 2 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,2
MC 615-a005
CAUSES: ELECTRICAL FAILURE
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
HDW/FUNC3/2R3/2R
r
w
C-71
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 404 ABORT:
ITEM:
FAILURE MODE:
MIALOSS OF OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I) DPS2) MASS MEMORY UNITS (MMU)
3) MIA
4)s)6)v)s)9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNCPRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2_
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2RLANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 1,2MC 615-0005
CAUSES: ELECTRICAL FAILURE
EFFECTS/RATIONALE:IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
HDW/FUNC3/2R3/2R
i
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I
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i
z
i
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l
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I
|
m
am
i
m
i
i
i
C-72 i
mm
F
1
w
i
w
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86. HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 405 ABORT:
ITEM: MIA
FAILURE MODE: ERRONEOUS OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l) DPS
2) MASS MEMORY UNITS (MMU)
3) MIA
4)s)6)v)s)9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 1,2MC 615-0005
CAUSES: ELECTRICAL FAILURE
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
HDW/FUNC
3/2R
3/2R
C-73
INDEPENDENT ORBITER ASSESSMENTORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86DPS
406
HIGHEST CRITICALITY HDW/FUNC
FLIGHT: 3/2R
ABORT: 3/2R
ITEM:FAILURE MODE:
WRITE ELECTRONICS
LOSS OF OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)2)
3)
4)5)
6)7)s)9)
DPS
MASS MEMORY UNITS (MMU)WRITE ELECTRONICS
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R .....RTLS: ....../_ _LIFTOFF: 3/2R TAL: _3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
_DING/SAFING: /NA
REDUNDANCY SCREENS: A [ 2 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 1,2MC 615-0005
CAUSES: ELECTRICAL FAILURE
EFFECTS/RATIONALE:IF THE ABILITY TO WRITE TO MMUS WERE LOST, THE MISSION COULD BE
TERMINATED EARLY. NO DANGER TO CREW OR VEHICLE.
REFERENCES:
zD
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U
I
m
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i
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B
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m
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i
!
m
B
_I
m
l
g
C-74 U
w
u
n
w
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 407 ABORT:
ITEM: RPC
FAILURE MODE: FAILED OPEN
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY :
i) DPS
2) MASS MEMORY UNITS (MMU)
3 ) POWER SUPPLY
4) RPCS)6)7)8)9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAY 1,2
PART NUMBER: MC 615-0005
CAUSES: BROKEN CONTACT
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
HDW/FUNC
3/2R
3/2R
m
C-75
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86
SUBSYSTEM: DPS
MDAC ID: 408
HIGHEST CRITICALITY
FLIGHT:
ABORT:
ITEM:
FAILURE MODE:
SWITCH
FAILED OPEN
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY :
I) DPS
2) MASS MEMORY UNITS (MMU)
3 ) POWER SUPPLY
4 ) SWITCH
5)
6)
7)8)9)
FLIGHT PHASE
PRELAUNCH: 3/2R
LIFTOFF: 3/2R
ONORBIT: 3/2R
DEORBIT: /NA
LANDING/SAFING: /NA
REDUNDANCY SCREENS:
CRITICALITIES
HDW/FUNC ABORT HDW/FUNC
" RTLS: 7NATAL: 3/2-R-
AOA: 3/2R
ATO: 3/2R
A [ 1 ] B [ P ]
LOCATION:
PART NUMBER:
AV BAY 1,2
MC 615-0005
c[P]
CAUSES: BROKEN CONTACT
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY'
REFERENCES:
HDW/FUNC
3/2R3/2R
I
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I
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m
m
I
mmm
J
m
J
B
g
mR
C-76 g
I
w
w
u
E,w
zri
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 409 ABORT:
ITEM:
FAILURE MODE:
SWITCH
FAILED CLOSED (ON)
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l) DPS
2) MASS MEMORY UNITS (MMU)
3) POWER SUPPLY
4) SWITCH
5)
6)
7)
S)
9)
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/3 TAL:
ONORBIT: 3/3 AOA:
DEORBIT: /NA ATO:
LANDING/SAFING: /NA
HDW/FUNC/NA
3/3
3/3
3/3
REDUNDANCY SCREENS: A [ 1 ] B [ P ] c[P]
LOCATION:
PART NUMBER:
AV BAY 1,2
MC 615-0005
CAUSES: STRAY PARTICLE
EFFECTS/RATIONALE:NONE
REFERENCES:
HDW/FUNC
3/3
3/3
C-77
I
DATE:
SUBSYSTEM:
MDAC ID:
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
410 ABORT:
ITEM:
FAILURE MODE:
CONTROL LOGIC
LOSS OF OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
1)
2)
3)
4)
5)
6)v)s)9)
DPS
MASS MEMORY UNITS (MMU)
CONTROL LOGIC
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 2 ]
LOCATION: AV BAY 1,2
PART NUMBER: MC 615-0005
B [ P ] C [ P ]
CAUSES: ELECTRICAL FAILURE
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 OR 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
HDW/FUNC
312R3/2R
g
mR
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I
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B
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l
q
i
U
U
m
l
mm
N
w
C-78
mm
I
mmZ
w
w
w
w
w
=
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITYDPS FLIGHT:
411 ABORT:
ITEM:
FAILURE MODE:
CONTROL LOGIC
ERRONEOUS OUTPUT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)
3)
4)s)6)v)s)9)
DPS
MASS MEMORY UNITS (MMU)
CONTROL LOGIC
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 2 ] B[P] C[P]
LOCATION:
PART NUMBER:
AV BAY 1,2
MC 615-0005
CAUSES: ELECTRICAL FAILURE
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 OR 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
REFERENCES:
HDW/FUNC3/2R3/2R
E ....
C-79
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE:
SUBSYSTEM:
MDAC ID:
10/03/86 HIGHEST CRITICALITY
DPS FLIGHT:
412 ABORT:
ITEM:
FAILURE MODE:
POWER SUPPLYFAILS OUT OF TOLERANCE OR INTERRUPT
LEAD ANALYST: K. PIETZ SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
I)
2)
3)
4)
S)
6)
V)
S)
9)
DPS
MASS MEMORY UNITS (MMU)
POWER SUPPLY
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: /NA
LIFTOFF: 3/2R TAL: 3/2R
ONORBIT: 3/2R AOA: 3/2R
DEORBIT: /NA ATO: 3/2R
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 2 ] B[P] C[P]
LOCATION:
PART NUMBER:
AV BAY 1,2
MC 615-0005
CAUSES: ELECTRICAL FAILURE
EFFECTS/RATIONALE:
IF BOTH MMUS FAIL, OPS 2 AND 3 SOFTWARE CANNOT BE LOADED.
HOWEVER, OPS 3 CAN BE UPLINKED OR BFS ENGAGED FOR ENTRY.
OF THESE OPTIONS REQUIRE THE USE OF MMUS.
REFERENCES:
HDW/FUNC3/2R3/2R
NEITHER
I
m
m
[]
mm
mm
mm
l
[]g
|
[]
mm
mm
I
I
m
C-80 mm
w
m
w
m
w
u
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 501 ABORT:
HDW/FUNC3/IR3/1R
ITEM:
FAILURE MODE:
CIA
LOSS OF OUTPUT TO MAIN ENGINE ON ONE CHANNEL
LEAD ANALYST: B. ROBB SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)5)6)
s)9)
DPS
ENGINE INTERFACE UNIT (EIU)CONTROLLER INTERFACE ADAPTER
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/1R
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: /NA AOA: 3/IR
DEORBIT: /NA ATO: 3/IR
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:
AV BAY 4,5,6
CAUSES: CONTROLLER INTERFACE ADAPTER FAILS
EFFECTS/RATIONALE:
LOSS OF THROTTLE COMMANDS, SHUTDOWN COMMANDS, LIMIT
INHIBIT/ENABLE COMMANDS, GPC SHUTDOWN COMMANDS, AND MPS DUMPCOMMANDS. LOSS OF ONE OF THREE COMMAND PATHS WILL BE VOTED
INVALID. NO EFFECT ON ENGINE OPERATIONS.
REFERENCES:
=
C-81
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 502 ABORT:
HDW/FUNC
3/!R
ITEM:
FAILURE MODE:
MIA
LOSS OF OUTPUT TO MAIN ENGINE ON ONE CHANNEL
LEAD ANALYST: B. ROBB SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)2)3)4)5)6)v)s)9)
DPS
ENGINE INTERFACE UNIT (EIU)MULTIPLEXER INTERFACE ADAPTER
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORTPRELAIYNCH: 3/2R RTLS:
LIFTOFF: 3/IR TAL:
ONORBIT: /NA AOA:DEORBIT: /NA ATO:
LANDING/SAFING: /NA
HDW/FUNC
3/IR3/IR3/1R
3/IR
REDUNDANCY SCREENS: A [ 1 ] B [ P ] c[P]
LOCATION:
PART NUMBER:AV BAY 4,5,6
CAUSES: MULTIPLEXER INTERFACE ADAPTER--FAILS
EFFECTS/RATION_ALE:LOSS OF THROTTLE COMMANDS, SHUTDOWN COMMANDS, LIMIT
INHIBIT/ENABLE COMMANDS, GPC SHUTDOWN COMMANDS, AND MPS DUMPCOMMANDS. LOSS OF ONE OF THREE COMMAND PATHS WILL BE VOTEDINVALID. NO EFFECT ON ENGINE OPERATIONS.
REFERENCES:
g
i
I
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l
!
l
l
l
I
IU
I
m
i
m
[]
[]
m
m
l
m
C-82 l
m
w
J
w
w
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITYSUBSYSTEM: DPS FLIGHT:
MDAC ID: 503 ABORT:
HDW/FUNC3/IR3/IR
ITEM: POWER CONTROL SWITCH
FAILURE MODE: LOSS OF OUTPUT TO MAIN ENGINE ON ANY OF THREE
COMMAND CHANNELS
LEAD ANALYST: B. ROBB SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
S)
6)v)s)9)
DPS
ENGINE INTERFACE UNIT (EIU)POWER CONTROL SWITCH
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: /NA AOA: 3/IR
DEORBIT: /NA ATO: 3/IR
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 4,5,6
CAUSES: EIU POWER CONTROL SWITCH FAILS OPEN
EFFECTS/RATIONALE:LOSS OF ALL COMMANDS AND STATUS OF THE ENGINE FOR THIS FAILURE
MODE THE LOSS OF THE ENTIRE EIU WILL RESULT IN ENGINE SHUTDOWN BY
CREW BY SWITCHING AC POWER TO THE ENGINE TO OFF POSITION.
REFERENCES:
w
C-83
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE: 10/03/86 HIGHEST CRITICALITY
SUBSYSTEM: DPS FLIGHT:
MDAC ID: 504 ABORT:
HDW/FUNC3/IR3/IR
ITEM: INTERNAL POWER SUPPLIES
FAILURE MODE: LOSS OF OUTPUT TO MAIN ENGINE ON ANY OF THREE
COMMAND CHANNELS
LEAD ANALYST: B. ROBB SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
5)
6)
7)
B)
9)
DPS
ENGINE INTERFACE UNIT (EIU)
INTERNAL POWER SUPPLIES
CRITICALITIES
FLIGHT-P_SE HbW/FUNC ...........ABO_RT
PRELAUNCH: 3/2R RTLS:
LIFTOFF: 3/IR TAL:
ONORBIT: /NA AOA:
DEORBIT: /NA ATO:
LANDING/SAFING: /NA
REDUNDANCY sCREENS: A [ 1 ] B [ P ]
HDW/FtmC_311R311R3/IR3/IR
c[p]
LOCATION:
PART NUMBER:
AV BAY 4,5,6
CAUSES: INTERNAL POWER SUPPLIES FAIL
EFFECTS/RATIONALE:
LOSS OF THROTTLE COMMANDS, SHUTDOWN COMMANDS, LIMIT
INHIBIT/ENABLE COMMANDS, GPC SHUTDOWN COMMANDS, AND MPS DUMP
COMMANDS. THE LOSS OF THE ENTIRE EIU WILL RESULT IN ENGINE
SHUTDOWN BY CREW BY SWITCHING AC POWER TO THE ENGINE TO OFF
POSITION.
REFERENCES:
u
zmm
R
mI
B
i
|
|m
msm
[]
m
Dl
B
ml
S
mm
m
C-84 m
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DATE:
SUBSYSTEM:
MDAC ID:
INDEPENDENT ORBITER ASSESSMENT
ORBITER SUBSYSTEM ANALYSIS WORKSHEET
10/03/86 HIGHEST CRITICALITY HDW/FUNCDPS FLIGHT: 3/IR
505 ABORT: 3/IR
ITEM:
FAILURE MODE:
ENGINES.
CONTROLLER INTERFACE ADAPTER
LOSS OF OUTPUT TO ONE OR THREE GPC ON STATUS OF
LEAD ANALYST: B. ROBB SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY:
l)
2)
3)
4)
5)
6)
7)
8)
9)
DPS
ENGINE INTERFACE UNIT (EIU)
CONTROLLER INTERFACE ADAPTER
CRITICALITIES
FLIGHT PHASE HDW/FUNC ABORT HDW/FUNC
PRELAUNCH: 3/2R RTLS: 3/IR
LIFTOFF: 3/IR TAL: 3/IR
ONORBIT: /NA AOA: 3/IR
DEORBIT: /NA ATO: 3/IR
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION:
PART NUMBER:AV BAY 4,5,6
CAUSES: CONTROLLER INTERFACE ADAPTER FAILURE
EFFECTS/RATIONALE:NO MAIN ENGINE MONITORING BY ONE OR THREE OF FOUR GPCS. MCC
CONFIRMS COMMAND PATH GOOD BY MONITORING 3-G THROTTLE CONTROL.
IF ENGINE IS NOT OPERATING, THE PUSHBUTTON FOR THE ENGINE MUST BE
USED TO INFORM GUIDANCE FOR PREVALVE CLOSURES. FLIGHT RULE 2-17
PRECLUDES RESTRINGING DURING POWERED ASCENT THROUGH MECO.
REFERENCES:
C-85
INDEPENDENT ORBITER ASSESSMENTORBITER SUBSYSTEM ANALYSIS WORKSHEET
DATE : 10/03/86 HIGHEST CRITICALITY HDW/FUNCSUBSYSTEM: DPS FLIGHT : 3/3
MDAC ID: 506 ABORT: 3/IR
ITEM: OIE
FAILURE MODE: LOSS OF OUTPUT TO S-BAND, MAINTENANCE RECORDER, ORLPS T-0 UMBILICAL
LEAD ANALYST: B. ROBB SUBSYS LEAD: B. ROBB
BREAKDOWN HIERARCHY :
I) DPS2) ENGINE INTERFACE UNIT (EIU)
3) OPERATIONAL INTERFACE ELEMENT4)s)6)
s)9)
CRITICALITIES
FLIGHT_P_KAS -_--_ HDW/_C ....... ABORT }{OW/_FUNC
PRELAUNCH: 3/2R RTLS : 3/IR
LIFTOFF: 3/3 TAL: 3/IR
ONORBIT : /NA AOA: 3/IR
DEORBIT: /NA ATO: 3/IR
LANDING/SAFING: /NA
REDUNDANCY SCREENS: A [ 1 ] B [ P ] C [ P ]
LOCATION: AV BAY 4,5,6P_T NUMBER:
CAUSES: OPERATIONAL INTERFACE ELEMENT FAILURE
EFFECTS/RATIONALE'_ _ _ iNO FM DATA RECORDING, NO MCC STATUS MONITORING OF ENGINE EXCEPT _IN DOWNLIST DATA FROM GPC.
REFERENCES :
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C-86 B
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MDAC ID
203
2O8
APPENDIX D
POTENTIAL CRITICAL ITEMS
ITEMun_u
IOP
CPU
FAILURE MODE
Premature Operation
Inadvertent Operation
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I
B
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ID
II
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