AXAF Acronym List

From an unknown TRW document of June 15, 1995 with additions supplied by users (denoted by *) .

A second, shorter list with many repeats but some additional acronyms can be found below.

Last revision: 21 June 1999

Search for an acronym (from either list) by using you browser's FIND function.

        A
        AA      Active Analog
        AC      Aspect Camera
        ACA     Aspect Camera Assembly
        ACACAL* ACA Calibration Data
        ACC     Aft Containment Cover
        ACCN    Audio Central Control Network
        ACD     AXAF Data Center
        ACE     Attitude Control Electronics
        ACF     Auto Collimating Flat
        ACIS    AXAF CCD Imaging Spectrometer (Penn State)
        ACIS-I* ACIS Imaging Array
        ACIS-S* ACIS Spectroscopic Array
        Aclr    Clear Aperture
        ACMOS   Automated Configuration Management Office System
        ACWP    Actual Cost of Work Performed
        ADC     Analog-to-Digital Converter
        ADS     Aspect Determination System
        ADU*    Analog to Digital Unit
        AESE    Airborne Electrical Support Equipment
        AF      Air Force
        AFD     Aft Flight Deck
        AFPRO   Air Force Plant Representative Office
        AFSC    Air Force System Command
        AFSCF   Air Force Satellite Control Facility
        AG      Air-to-Ground
        AGC     Automatic Gain Control
        Ageom   Geometric Aperture
        AI      Action Item; Artificial Intelligence
        AIAA    American Institute of Aeronautics and Astronautics
        AID     Analog Input, Differential
        AIS     AXAF Information System
        aka     also known as
        A/L     Airlock
        ALERTS  [Not an acronym, a system for notice of potential problems]
        AM0     Air Mass Zero
        AO*     Announcement of Opportunity
        AOA     Abort Once Around
        AOD     Analog Output, Differential
        AOS     Acquisition of Signal
        AP      Authority to Proceed (also ATP)
        APART   Arizona's Program for the Analysis of Radiation Transfer - 
                A stray light analysis computer program for finite element
                radiation propagation which divides radiation sources and                       collectors into differential sections then
                calculates radiation transferred between them (BRO/BECD)
        APF     Automated Procurement File
        APM     Assistant Project Manager
        AR      Administration Room; Anti-Reflective
        ARES    Automated Real-Time Evaluation System
        ARM     Alignment Reference Mirror
        ARU     Attitude Reference Unit (IUS)
        ASAP    Advanced Systems Analysis Package (BRO)
        ASC     AXAF-I Science Center
        ASCDS* ASC Data Analysis System
        ASCII* American National Standard Code for Information Exchange
        ASK     Airborne Support Equipment
        ASOS    An assembly computer language
        ASPQUAL* Aspect Solution Quality Indicators
        ASR*    Acivity Scheduling Requirement
        ASVT*   Automated Software Verification Test-set
        A&T     Assembly and Test
        ATC     Absolute Time Command (Stored Command related)
        ATCP    Absolute Time Command Processor
        ATCS    Active Thermal Control System
        ATO     Abort to Orbit
        ATOHMS  Assembly and Test Operations Hardware Management System
        ATP     Automated Test Procedures; Authority to Proceed
        ATS     Absolute Time Sequence
        A&S     Avionics and Software
        A&V     Assembly and Verification
        AWG     American Wire Gauge
        AXAF-I  Advanced X-Ray Astrophysics Facility-Imaging
        
        B
        BAC     Boeing Aerospace Company
        BATT    Battery
        B/B     Breadboard
        BBE     Baseband Equipment
        BCO     Beam Combing Optic (replaced by FTM)
        BCS     Bragg Crystal Spectrometer
        BCSS    Boeing Computer Support Service
        BCT     Bit Cell Time
        BCWP    Budget Cost of Work Performed
        BCWS    Budget Cost of Work Scheduled
        BECD    Ball Electro-Optical Cryogenics Division
        BER     Bit Error Rate
        BG      Bare GFRP
        BI*     Back-illuminated
        BITE    Built-in Test Equipment
        BOD     Bright Object Detector
        BOE     Basis of Estimate
        BOL     Beginning of Life
        BOT     Beginning of Tape
        BPA     Bus Protection Assembly
        BPOCC   Backup Payload Operations Control Center
        BPSK    Bi-Phase Shift Keyed
        bps     bits per second
        BRF     Band Reflex Unit
        BRDF    bi-directional reflectance distribution function (L/E => Radiance of the source over
                Irradiance at the source) (BRO)
        BRO     Breault Research Organization, Inc.
        BRU     Bus Regulator Unit
        BSF     Back Surface Field
        BSI     Broad Source Integration (BRO)
        BSR     Back Surface Reflective
        BTC     Battery Triable Charger
        BTD     Burn to Depletion
        BTU     Bus Terminal Unit

        C
        CADM    Configuration and Data Management
        CAD/CAE Computer-Aided Design/Computer-Aided Engineering
        CAD/CAM Computer-Aided Design/Computer-Aided Manufacturing
        CAP     Central Aperture Plate; Command Action Procedure*
        CAPA    Center Aperture Plate Assembly
        CARD    Constraints, Restrictions, and Limitations Document
        CC*     Continuous Clocking
        CCAM    Contact/Collision Avoidance Maneuver or Collision/Contamination Avoidance
                Maneuver
        CCB     Configuration Control Board
        CCD     Charge-Coupled Device
        CCDM    Communications, Command and Data Management
        CCIR    International Radio Consultative Committee
        CCMD*   Continuous Clock Mode
        CCN     Contract Change Notice
        CCSDS   Consultative Committee for Space Data Systems
        CCTV    Closed Circuit Television
        CDA     Critical Design Audit
        CDM     Command and Data Management
        CDMS    Command and Data Management Simulator
        CDOS    Customer Data and Operations System
        CDR     Critical Design Review
        CDS     Contamination Detection System; Command Data System (IUS)
        CD&SC   Communications Distribution and Switching Center
        CDW     Command Data Word
        CE      Cargo Element
        CEA     Control Electronics Assembly
        CEI     Contract End Item
        CFE     Contractor Furnished Equipment: Customer Furnished Equipment
        CG      Center of Gravity
        CGCD*   Crossed Grid Charge Detector
        CI      Configuration Inspection
        CID     Cable Interconnect Diagram, Charge Injection Device
        CIL     Critical Items List
        CIR     Cargo Integration Review
        CIS     Contract Inventory System
        CITE    Cargo Integration Test Equipment
        CIU     Communication Interface Unit (IUS)
        cm      centimeter
        CM      Configuration Management, Center of Mass
        CMA     Configuration Management Accounting
        CMD     Command
        CMO     Configuration Management Officer/Office
        CMRR    Common Mode Rejection Ratio
        CMS     Configuration Management System; Code Management Software;
                Command Management System
        CMV     Common Mode Voltage
        COCOMO  Constructive Cost Model
        COFW    Certificate of Flight Worthiness
        CoI*    Co-Investigator
        COLDEN* Calculate Neutral Hydrogen Column Density
        COQ     Certification of Qualification
        COR     Contractor Operations Review
        COTS    Commercial Off the Shelf
        CPC     Computer Program Component, Cargo Processing Contractor
        CPCEI   Computer Program Component End Item
        CPE     Control Processing Electronics
        CPMO    Central Printing Management Office
        CPU     Central Processing Unit
        CR      Computer Room; Change Request; Cosmic Ray*
        CRL     Constraint, Restriction, and Limitation
        CRT     Cathode Ray Tube
        CRU     Contingency Replacement Unit
        CSCI    Computer Software Configuration Item
        CSF     Customer Servicing Facility
        CSG     Command Sequence Generator
        CDIM*   Cadre Simulation
        CSR*    Center for Space Research (MIT)
        CSS     Coarse Sun Sensor
        CSSA    Coarse Sun Sensor Assembly
        CSOC    Consolidated Space Operations Center
        CSS*    Coarse Sun Sensor
        CTD     Charge Transfer Device
        CTE     Coefficient of Thermal Expansion; Charge Transfer Efficiency
        CTI*    Charge Transfer Inefficiency
        CTT*    Calibration Task Team
        CTU     Command and Telemetry Unit
        CTV     Compatibility Test Van
        CU      Computer Unit (IUS)
        CWA     Conference Work Area
        CXC*    Chandra X-ray Center
        CXO*    Chandra X-ray Observatory
        CY      Calendar Year

        D        
        D&C     Display and Control
        D/A     Digital to Analog
        DAC     Digital-to-Analog Converter
        db      decibel
        DB      Data Base
        DBMS    Data Base Management System
        DBS     Data Bus System
        dc      direct current
        DCF     Data Capture Facility
        DCR     Design Certification Review
        DDT&E   Design Development Test and Evaluation
        DDU     Deployment Drive Unit
        DEA     Drive Electronics Assembly
        Dec*    declination
        DEC     Digital Equipment Corporation
        DFI     Developmental Flight Instrumentation
        DIH     Discrete Inputs, high level
        DIL     Discrete Inputs, low level
        D/L     Downlink (RF Downlink)
        DMO     Data Management Office
        DMR     Detail Mission Requirements
        DMS     Data Management Subsystem
        DMSE    Deployment Mission Support Equipment
        DoD     Department of Defense
        DOD     Depth-of-discharge
        DOF     Degrees of Freedom
        DOH     Discrete Outputs, high level
        DOL     Discrete Outputs, low level
        DOMSAT  Domestic Satellite
        DOS     Disk Operating System
        DOT     Detailed Operations Timeline
        DOY*    Day of Year
        DP      Deployment Panel
        DPA     Destructive Parts Analysis
        DPFP    Double Precision Floating Point
        DPR*    Document Problem Report
        DR      Data Requirement
        DRIRU   Dry Rotor Inertial Reference Unit
        DRM     Design Reference Mission
        DSD     Data Systems Directorate
        DSI     Delivered Source Instructions
        DSN     Deep Space Network
        DTS     Dynamic Target Simulator

        E
        e       emissivity
        EAC     Estimate at Completion
        EC*     Ecliptic Coordinates
        ECD     Engineering Change Directive
        ECI     Earth-Centered Inertial
        ECO     Engineering Change Order
        ECP     Engineering Change Proposal
        ECR     Engineering Change Request
        EDE     Extended Definition Effort; Electrical Distribution Equipment
        EDDS    Engineering Data Distribution System
        EDI     Electrical Design Integration
        EDP     Electronic Data Processing
        EEC     Extendible Exit Cone (IUS)
        EED     Electroexplosive Device (IUS)
        EHS*    Enhanced HOSC System
        EIPS    Electron Impact Source
        EKE     Electrical, Electronic, and Electromagnetic (Parts)
        EEPROM  Electrically Erasable Programmable Read-Only Memory
        EFL     Effective Focal Length (BECD)
        EGSE    Electrical Ground Support Equipment
        EIA     Electrical Interface Assembly
        EIRP    Effective Isotropic Radiated Power
        EKC     Eastman Kodak Company
        ELS     Eastern Launch Site
        EM      Engineering Model
        EMC     Electromagnetic Compatibility
        EMI     Electromagnetic Interference
        EMOR    Emergency MOR
        EMISH   EMI Safety Margin
        EMU     Extravehicular Mobility Unit
        ENGR    Engineer
        EOC     Estimate on Completion
        EOL     End-of-Life
        EOT     End of Tape
        EPDS    Electrical Power and Distribution Subsystem
        EPHIN   Electron Proton Helium Instrument
        EPS     Electrical Power Subsystem
        ER*     Engineering Request
        ESA     Earth Sensor Assembly
        ESC     Engineering Support Center
        ESD     Electro-Static Discharge
        ESE     Electrical Support Equipment
        ESF     Engineering Support Function
        ET      External Tank
        ETR     Eastern Test Range
        EUV*    Extreme Ultraviolet
        eV      electron Volt
        EVA     Extra-Vehicular Activity

        F
        F/W     Firmware
        FAM     Five Axis Mount
        FBT     Fixed Base Test
        FCA     Final Configuration Audit
        FCC     Forward Contamination Cover; Federal Communications Commission
        FCCD    Focal Plane CCD
        FCHP    Fixed Conductance Heat Pipe
        FCL     Functional Capabilities List
        FCM     Flight Contamination Monitor
        FDF     Flight Dynamics Facility
        FEM     Forward Equipment Module (IUS)
        FEP     Fluorinated Ethylene Plastic (Teflon coating - thermal control material)
        FEPAL   FEP Aluminum (back surface coated w/vacuum deposited aluminum)
        FEPAGIN FEP Silver Inconel (back surface coated with vacuum deposited silver w/Inconel
                overcoat)
        FI*     Focal plane Instrumentation; Front Illuminated CCD Chip
        Fid; FID        Fiducial
        FIDPROPS* Fiducial Light Properties
        FIFO    First In First Out
        FIPP    Fabrication/Inspection Process Procedures
        FITS*   Flexible Image Transport System
        FL      Fiducial Lights
        FLA     Fiducial Light Assembly
        FLC     Fiducial Light Controller
        FLCA    Fiducial Light Control Assembly
        FM      Frequency Modulation
        FMEA    Failure Mode Effects Analysis
        FOM     Figure of Merit
        FOSR    Flexible Optical Solar Reflector (IUS)
        FOT     Flight Operations Team
        FOV     Field-of-view
        FP      Focal Plane
        FPC*    Flow Proportional Counter
        FPA     Focal Plane Assembly
        FPGA    Field Programmable Gate Array
        fps     feet per second
        FPSI    Focal Plane Science Instrument
        FPV     Flow Proportioning Valve
        FPX*    Focal Plane X
        FPY*    Focal Plane Y
        FRB     Failure Review Board
        FRGF    Flight Releasable Grapple Fixture
        FRR     Flight Readiness Review
        F/S     Focus Structure (BECD)
        FS      Flight Software, Full Scale
        FSE     Factory Support Equipment
        FSK     Frequency Shift Keyed
        FSS     Flight Support System; Fine Sun Sensor*
        FSSA    Fine Sun Sensor Assembly
        FSSE    Fine Sun Sensor Electronics
        FTA     Fiducial Transfer Assembly
        FTM     Fiducial Transfer Mirror
        FTS     Fiducial Transfer System (aka Fiducial Transport System)
        FUV*    Far UV
        FWHM    Full Width Half Maximum
        FY      Fiscal Year

        G
        g       Acceleration due to gravity (gravity constant @ 32.17 feet/sec/sec)
        GCF     Geometrical Configuration Factor [(Solid Angle)/~ => stray light analysis]
        GDE     Gimbal Drive Electronics
        GESS    Grating Element Support Structure
        GFE     Government Furnished Equipment
        GFP     Government Furnished Product/Property
        GFRC    Graphite Fiber Reinforced Cyanate
        GFRP    Graphite Fiber Reinforced Plastic
        GFY     Government Fiscal Year
        GMM     Geometric Math Model (IUS)
        GMT     Greenwich Mean Time
        GN      Ground Network
        GN&C    Guidance, Navigation and Control
        GND     Ground
        GO      Guest Observer
        GOT*    Ground Operations Team
        GPC     General Purpose Computer
        GPS     Global Positioning System
        GPSS    General Purpose Simulation System
        GREP    Graphite Reinforced Epoxy Plastic
        GRO     Gamma Ray Observatory
        GSE     Ground Support Equipment
        GSFC    Goddard Spaceflight Center
        GSPROPS* Guide Star Properties
        GSS     Ground Support Software
        GSTDN   Ground Spaceflight Tracking and Data Network
        GTO*    Guaranteed Time Observer
        GUI*    Graphical User Interface
        GYROCAL* Gyro Calibration Data

        H
        HATS    HRMA Alignment Test System
        H/P     Hyperboloid/Paraboloid Mirror Pair
        HCE     HRMA Control Electronics
        HDOS    Hughes-Danbury Optical Systems
        HEAO    High Energy Astrophysical Observatory
        HEASARC* High Energy Astrophysics Science Archive Research Center
        HEG*    High Energy Grating
        HESF*   High Energy Suppression Filter
        HESS    HETG* Support Structure
        HETA    HRMA Engineering Test Article
        HETG    High Energy Transmission Grating (MIT)
        HETGS   High Energy Transmission Grating Spectrometer
        HGA     High Gain Antenna
        HGAD    High Gain Antenna Drive
        HIU     Host Interface Unit
        HMI     Human Machine Interface
        HMSS    HRMA Mirror Support Sleeve, HRMA Module Support Structure
        HOL     High Order Language
        HOSC    Huntsville Operations Support Center
        HP      Hewlett Packard
        HPD*    Half Power Diameter
        HQ*     Headquarters
        HRC     High Resolution Camera (SAO)
        HRI*    High Resolution Imager
        HRL*    Hardware Release List
        HRMA    High Resolution Mirror Assembly
        HS      Hybrid Simulator
        HSA     HRMA Shutter Assembly
        HSI*    High Speed Imager
        HSS     HRMA Structural Simulator
        HST     Hubble Space Telescope
        HTRS    Heaters
        HXDS*   HRMA X-ray Detection System (at the XRCF)

        I
        I&C     Instrumentation & Communication
        ICD     Interface Control Document; Interface Control Drawing
        ICS     Interpretive Computer Simulation, Integrated Checkout
                Station
        ID      Identifier, Inner Diameter
        IDD     Interface Design Document
        IDS*    Interdisciplinary Scientist
        I/F     Interface
        IGSE    Instrument Ground Support Equipment
        I/O     Input/Output
        IOC     Inter Office Correspondence
        IOE     Input/Output Electronics
        I/OM    Input/Output Module
        IOS     Input/Output Slice
        IP      Instrumentation Processor
        IPI     Instrument Principal Investigator
        IPS     Integral Propulsion System (now PS); Interface Problem Sheet (IUS)
        IPSD    Interface Plans & Schedules Document (IUS)
        IRAF*   Image Reduction and Analysis Facility
        IRD     Interface Requirements Document
        IRN     Interface Revision Notice
        IRU     Inertial Reference Unit
        ISATS   Integrated Spacecraft Automated Test System
        ISIM    Integrated Science Instrument Module
        ISDES   Integrated Spacecraft Data Exchange System
        ISU     Instrument Switching Unit
        I&T     Integration and Test
        ITD     Inception to Date
        ITP     Interface Test Program
        ITS     Integrated Telescope System
        IU      Interface Unit
        IUE*    International Ultraviolet Explorer
        IUS     Inertial Upper Stage
        IV&V    Integrated Verification and Validation
        IWG     Interface Working Group

        J
        JANTX   Joint Army/Navy Transistor Extra Testing
        JD*     Julian Date; Julian Day Number
        JIS     Joint Integrated Simulation
        JISWG   Joint Integrated Simulation Working Group
        JPL     Jet Propulsion Laboratory
        JSC     Johnson Space Center

        K
        K       Kapton
        KAL     Aluminized Kapton (thermal control material)
        kbps    kilobits per second
        keV     kiloelectron Volt (thousands of electron volts)
        km      kilometer
        KSC     Kennedy Space Center

        L
        LAE     Liquid Apogee Engines
        LAN     Local Area Network
        LCC     Life Cycle Costs; Launch Control Center
        LED     Light Emitting Diode
        LEO     Low Earth Orbit
        LESF*   Low Energy Suppression Filter
        LETG    Low Energy Transmission Grating (SRU)
        LETGS   Low Energy Transmission Grating Spectrometer
        LGA     Low Gain Antennae
        LHCP    Left Hand Circularly Polarized
        LN2     Liquid Nitrogen
        LOE     Level of Effort
        LOS     Line-of-Sight, Loss of Signal
        LPS     Launch Processing System
        LRF*    Line Response Function
        LRU     Line Replaceable Unit
        LSB     Least Significant Bit
        LSF*    Line Spread Function
        LSSP    Launch Site Support Plan (KSC/IUS)
        LTM     Load Transformation Matrix
        LVLH    Local Vertical Local Horizontal (IUS)

        M        
        M&P     Materials and Processes
        M&RO    Maintenance and Refurbishment Operations
        MA      Multiple Access
        MAR     Mission Analysis Room
        MARX*   Model of AXAF Response to X-rays
        MAS     Mirror Alignment Station
        mbps    megabits per second
        MCC     Mission Control Center (@ JSC)
        MCE     Mechanism Control Electronics
        MCP     Microchannel Plate
        MDB     Multiplex Data Bus
        MDE     Motor Drive Electronics
        MDF     Manipulator Development Facility
        MDI     Mechanical Design Integration
        MDM     Multiplexer Demultiplexer
        ME      Main Engine
        MEC     Miniature Embedded Converter
        MECO    Main Engine Cutoff
        MEG*    Medium Energy Grating
        MET     Mission Elapsed Time
        MeV     Million Electron Volts
        MGSE    Mechanical Ground Support Equipment
        MILA    Merritt Island Launch Area
        MIPS    Million Instructions Per Second
        MIS     Management Information System
        MIT*    Massachusetts Institute of Technology
        MJD*    Modified Julian Date
        MLI     Multi-Layer Insulation
        MLP     Mobile Launcher Platform
        MM      Maneuver Mode
        MMI     Marshall Management Instruction
        MMS     Multi-Mission Modular Spacecraft
        MO      Mission Operations
        MO&DSD  Mission Operations and Data Systems Directorate
        MODS    Mission Operations and Data System
        MOP     Master Observing Plan, Mission Operations Plan
        MOR     Mission Operations Room
        MPCAT*  Mission Planning Catalog
        MPE*    Max Planck Institut fuer Extraterrestrische Physik
        MPR     Mission Planning Room
        MPS     Modular Power Subsystem, Mission Planning System
        MPWA    Manufacturing Project Work Authorization
        MRB     Materials Review Board
        MRMS    Mobile Remote Manipulator System
        MRR     Monthly Requirements Review
        MSA     Module Structure Assembly
        MSB     Most Significant Bit
        MSE     Mechanical Support Equipment
        MSFC    Marshall Space Flight Center
        MSOCC   Multi-Satellite Operations Control Center
        MSR     Mission Support Room
        MSS     Mirror Support Sleeve
        MST*    Mission Support Team
        MTA     Magnetic Torquer Assembly
        MTF     Modulation Transfer Function
        M/U     Make-Up
        MUA     Material Usage Agreement
        MUPS    Momentum Unloading Propulsion System
        MUX     Multiplexer

        N
        NASA    National Aeronautics and Space Administration
        NASCOM  NASA Communications Network
        NASTRAN NASA Structural Analysis Program
        NTIA    National Telecommunications and Information Administration
        NAV     Navigation
        NBF     Neutral Buoyancy Facility
        NBT     Neutral Buoyancy Testing
        NCC     Network Control Center
        NEA     Noise Equivalent Angle; Non-Explosive Actuator
        NGT     NASA Ground Terminal
        NHB     NASA Handbook
        NISN*   NASA Integrated Services Network
        NIT     Normalized Irradiance Transmission (see PST - stray light radiance analysis)
        NM      Normal Mode
        NMM*    Normal Maneuver Mode
        nmi     nautical mile
        NOCC    NASA Operations Control Center (@ JPL)
        NPM*    Normal Pointing Mode
        NRA*    NASA Research Announcement
        NRAO*   National Radio Astronomy Observatory
        NRT     Near Real-Time
        NRZ     Non-Return to Zero
        NRZ-L   Non-Return to Zero-Level
        NRZ-M   Non-Return to Zero-Mark
        NSI     NASA Standard Initiator
        NSPAR   Nonstandard Parts Approval Request
        NSSDC   National Space Science Data Center
        NSTS    National Space Transportation System
        NSTSO   National Space Transportation System Office
        NTE     Not to Exceed
        NTSC    National Television Standards Committee
        NVR     Non-Volatile Residue

        O
        OAC*    Orbit Activation and Checkout
        OB      Optical Bench
        OBA     Optical Bench Assembly
        OBC     On-Board Computer
        OBI     Operation Readiness Inspection
        OBP     On-Board Processor
        OBS     Observatory
        OBSCAT* Observing Catalog
        OBSVIS* Observation Visualizer
        O&C     Operations & Checkout
        OCC     Operations Control Center
        OCDP    Operations Capability Development Plan
        OCLI    Optical Coating Laboratories, Inc. (Iridium ~300A; Chromium binder ~120A; Hi
                Vacuum Magnetron Sputtering Plasma)
        OD      Outside Diameter
        ODB     Operations Data Base
        ODH     Outside Data Handbook
        ODM     Operational Data Messages
        OFF*    AXAF Operational Flight Firmware
        OFP*    AXAF Operational Flight Program
        OFLS    Off-Line System
        OFS     On Board Flight Software
        OGM     Objective Grating Mechanism
        OGS     Operations Ground Systems
        OGSR    Operations Ground Systems Requirements
        OMIS    Operations Management Information System
        OMS     Orbital Maneuvering System
        ONLS    On-Line System
        OOV*    On-Orbit Verification
        OP      Operations Procedures
        OPF     Orbiter Processing Facility
        OPR     Orbiter/Payload Recorder
        OPS     Operations
        OPSIM* Operational Simulator
        OR      Observation Request
        ORD     Observation Request Processor
        ORI     Operation Readiness Inspections
        ORU     Orbital Replacement Units
        ORUC    ORU Carrier
        OS      Operations Simulator, Orbital Servicing; Operating System*
        OSC     Operations Support Center
        OSF     Office of Space Flight
        OSM     Optical Structure and Mechanisms
        OSR     Optical Solar Reflector (IUS)
        OSSA    Office of Space Science and Applications
        OSTDS   Office of Space Tracking and Data Systems
        OTG     Objective Transmission Grating
        OU      Ordnance Unit
        OV      Orbital Validation
        OWG     Operations Working Group

        P
        PA      Performance Assurance, Passive Analog
        PAR     Performance Assurance Requirements
        PAS     Problem Assessment System
        PC      Printed Circuit
        PCAD    Pointing Control and Aspect Determination
        PCIS    Project Configuration Information System
        PCM     Pulse Code Modulation
        PCMO    Program Configuration Management Office
        PCR     Payload Changeout Room
        PCU     Power Control Unit
        PDA     Preliminary Design Audit
        PDF     Programmable Data Formatter
        PDI     Payload Data Interleaver (NSTS)
        PDL     Program Design Language
        PDM     Primary Drive Motor
        PDR     Preliminary Design Review
        PDU     Power Distribution Unit
        PE      Perkin-Elmer
        PEA     Processing Electronics Assembly
        PEL     Precision Elastic Limit
        PEM     Power Electronics Module
        PET*    Phase Elapsed Time
        PFA     Perfluoroalkoxy (thermal control material)
        PFAAGIN PFA Silver Inconel (back surface coated with vacuum deposited silver w/Inconel
                overcoat)
        PGHM    Payload Ground Handling Mechanism
        PH*     Pulse Height
        PHA*    Pulse Height Amplitude
        PHSF    Payload Hazardous Servicing Facility
        PI      Principal Investigator; Payload Interrogator
        PIMMS* Portable Interactive Multi-mission Software
        PIN     Part or Identification Number
        PIND    Particle Impact Noise Detection
        PIRN    Preliminary Interface Revision Notice
        PIP     Payload Integration Plan
        P/L     Payload
        PLB     Payload Bay
        PLBD    Payload Bay Door
        PLL     Phase-Locked Loop
        PM      Pointing Mode, Pulse Modulated
        PMI     Person Machine Interface
        PMIS    Performance Measurement Information System
        PM&P    Parts, Materials and Processes
        PMR     Project Management System
        PMS     Performance Measurement System
        PN      Pseudo Random Noise
        POCC    Payload Operations Control Center
        POF     Payload Operations Function
        POR     Project Office Room
        PPM*    Positions & Proper Motions
        P-P     Peak-to-Peak
        PPF     Payload Processing Facility
        PPM     Parts Per Million
        PRD     Project Requirements Document
        PRF     Point Response Function: Pulse Repetition Frequency
        PRLA    Payload Retention Latch Assembly
        PRLAS   Payload Retention Latch Actuator System
        PROM    Programmable Read Only Memory
        PRN     Preliminary Revision Notice
        PROS*   Post-reduction Off-Line Software
        PRR     Program Readiness Review
        PRU     Power Regulator Unit
        PS      Propulsion System; Project Scientist*
        PSAT    Predicted Site Acquisition Table
        PSD     Power Spectral Density
        PSDA    Power Switching and Distribution Assembly
        PSDU    Power Switching Distribution Unit
        PSE     Power Switching Electronics
        PSF     Point Spread Function
        PSK     Phase Shift Keyed
        PSP     Payload Signal Processor
        PSPC*   Position Sensitive Proportional Counter
        PST     Point Source Transmission (NIT standard - stray light analysis)
        PSS     Portable Spacecraft Simulator
        PSU     Pyro Switching Unit (IUS); Pennsylvania State University*
        PTCR    Payload Terminal Connection Room
        PTU     Power Transfer Unit (IUS)
        PWA     Project Work Authorization

        Q
        QA      Quality Assurance
        QE*     Quantum Efficiency

        R        
        RA      Right Ascension
        RAAN    Right Ascension of the Ascending Node
        RAM     Random Access Memory
        R/C     Retroreflector/Collimator
        RCS     Reaction Control System
        RCTU    Remote Command and Telemetry Unit
        RCVR    Receiver
        RDBMS   Relational Data Base Management System
        RDE     Responsible Design Engineer
        REQTRACE        Requirements Trace Tool (Simulation)
        RF      Radio Frequency
        RFC     RF Combiner
        RFCU    RF Control Unit
        RFI     Radio Frequency Interference
        RFOV    Reduced Field of View
        RFPA    Radio Frequency Pre-Amplifier
        RFT     Retroreflector Field Tracker
        RHCP    Right Hand Circularly Polarized
        RI      Rockwell International
        RID     Review Item Discrepancy
        RIMU    Redundant Inertial Measurement Unit (IUS)
        RISC    Reduced Instruction Set Compute'
        RIU     Remote Interface Unit
        RMS     Remote Manipulator System
        rms     root mean square
        RM/RCC  Reference Mirror/Retro-Reflective Collimator
        ROM     Read Only Memory; Rough Order of Magnitude (cost)
        ROSAT* Roentgen Satellite
        RPS*    Remote Proposal Submission
        RR      (Program) Requirements Review
        RRC     Retroreflector Collimator
        RSS     Rotating Service Structure
        rss     root sum square
        R/T     Real-time
        RT      Real-Time
        RTC     Relative Time Command
        RTCP    Relative Time Command Processor
        RTLS    Return to Launch Site
        RTM     Resin Transfer Molding
        RTS     Relative Time Sequence
        RTSS    Real-Time System Simulator
        RTV     Room Temperature Vulcanizing
        RW      Reaction Wheel
        RWA     Reaction Wheel Assembly
        RWEA    Reaction Wheel Electronics Assembly

        S
        S/A; SA Solar Array
        S&D     Space and Defense Sector
        SAA     South Atlantic Anomaly
        SAAD    South Atlantic Anomaly Detector
        SADA    Solar Array Drive Assembly
        SAIL    Systems Analysis and Integration Laboratory
        SAL     Simulation Analysis Language
        SAO     Smithsonian Astrophysical Observatory
        SAP*    Special Activity Procedure
        SAR     Software Acceptance Review
        SAS     Solar Array Simulator
        SATRR   Software Acceptance Test Readiness Review
        S/C; SC Spacecraft
        SCA     Safing and Control Assembly
        SCCWG   Software Configuration Control Working Group
        SCMWG   Software Configuration Management Working Group
        SCD     Source Control Drawing
        SCDR    Software Critical Design Review
        SCM     Software Configuration Management
        SCMW    Software Configuration Management Working Group
        SCN     Specification Change Notice
        SCO     Software Change Order
        SCMO    Software Configuration Management Officer
        SCP     Stored Command Program
        SCR     Simulation Control Room
        SCSHM   Safe Contingency Sun Hold Mode
        SCTS    Space Cargo Transportation System
        SCU     Signal Conditioning Unit (IUS)
        SD      Serial Digital;Space Division (AFSC)
        SDA     Sun-shade Door Assembly
        SDF     Software Development Facility
        SDM     Sun-shade Door Mechanism
        SDP     Software Development Plan
        SDPF    Science Data Processing Facility
        SDS     Software Design Specification
        SDTS    Software Development Test Specification
        SE      Systems Engineering (DR)
        SE&I    Systems Engineering and Integration (TRW/AXAF)
        SEA     Support Electronics Assembly; SIM Electronics Assembly
        SER     Systems Engineering Report (BECD)
        SEU     Single Event Upset
        SFCA    Software Final Configuration Audit
        SI      Science Instrument
        SIAH    Science Instrument Accommodation Hardware
        SIC     Science Instrument Compartment
        SIHM    Safe Inertial Hold Mode
        SIM     Science Instrument Module
        SIP     Standard Interface/Panel
        SIRD    Support Instrumentation Requirements Document
        SIRTF   Space Infrared Telescope Facility
        SISS    Science Instrument Support Structure
        SLS     Stray Light Shade
        S&MA    Safety and Mission Assurance
        SMAC    System Monitor and Control
        SMCH    Standard Mixed Cargo Harness
        SMF*    Software Maintenance facility
        SMIE    Safing Monitor Interface Electronics
        SMP     Software Management Plan
        SMPE    Safing Monitor Processor Electronics
        SMS     Structures and Mechanical Subsystem
        SN      Space Network
        SNR     Signal-to-Noise Ratio; Supernova Remnant*
        SO      Servicing Operations
        SOC     Simulations Operations Center
        SOGS    Science Operations Ground System
        SOP*    Standard Operating Procedure
        SORD    Support Operations Requirements Document
        SOT*    Science Operations Team
        SOW     Statement of Work
        SP      System Procedure
        SPA     Signal Processor Assembly
        SPDR    Software Preliminary Design Review
        SPFP    Single Precision, Floating Point
        SPICE   Simulated Program with Integrated Circuit Emphasis
        SPIF    Shuttle Payload Interface Facility
        SPL     Sound Pressure Level
        SPLAN   Space Park Local Area Network
        SPM     Subproject Manager
        SPR     Software Problem Report
        SPS     Signal Processing Subassembly
        SQA     Software Quality Assurance
        SQL     Structured Query Language
        SRM     Solid Rocket Motor
        SRM&QA  Safety, Reliability, Maintainability & Quality Assurance
        SRON    Space Research Organization of the Netherlands
        SRR     System Requirements Review
        SRS     Software Requirements Specification
        SRU     (A university in Utrecht, the Netherlands.) (LETG)
        S.S.    Steady State
        SS      Servicing Software
        SSA     S-band Single Access; Support Structure Assembly
        SSD*    Solid State Detector
        SSDL    Sun-shade Door Launch Lock
        SSE     Space Support Equipment
        SSF     Space Station Freedom
        SSHM    Safe Sun Hold Mode
        SSP     Standard Switch Panel; Space Shuttle Program
        SSR     Shift Staging Room; Solid State Recorder
        SST     Second Surface Teflon
        SST/K   SST/Kapton laminate
        SSV     Space Shuttle Vehicle
        SSWG    System Software Working Group
        STC     SIM Thermal Control
        STDN    Spaceflight Tracking and Data Network
        STE     Special Test Equipment
        STG     Stage
        STGT    Secondary TDRS Ground Terminal
        STOL    Standard Test and Operations Language
        STPS    Summary Task Planning Sheet
        STRAP   A utility program supplied with ASAP (BRO)
        STS     Space Transportation System
        STSCI* Space Telescope Science Institute
        SURS    Standard Umbilical Retention/Retraction System
        SVATRR  Software Validation Test Readiness Review
        SVTRR   Software Verification Test Readiness Review
        S/W     Software
        SW      Switch
        SWAG    Scientific Wild-a-Guess
        SWG*    Science Working Group
        SWRR    Software Requirements Review

        T        
        T-0     Time-Zero (launch)
        T/C     Thermal Control
        T/R     Tape Recorder
        TAEM    Terminal Approach Energy Management
        TAI*    International Atomic Time
        TAM     Tri-Axial Magnetometer
        TAME    Tri-Axial Magnetometer Electronics
        TBD     To Be Determined
        TBR     To Be Reported; To Be Reviewed; To Be Revised; To Be Resolved
        TBS     To Be Supplied
        TDB*    Barycentric Dynamical Time
        TC      Test Conductor
        TCS     Thermal Control Subsystem
        TDE     Torquer Drive Electronics
        TDI     Thermal Design Integration
        TDR     Test Discrepancy Report
        TDRS    Tracking and Data Relay Satellite
        TDRSS   Tracking and Data Relay Satellite System
        TE*     Timed Exposure
        TEC     Thermo-Electric Cooler
        TFOV    Total Field of View
        TFTE    Telescope Forward Thermal Enclosure
        TIM     Technical Interchange Meeting
        TJD     Time Julian Day
        TLM;TM  Telemetry
        TMA     Technology Mirror Assembly
        TMM     Thermal Math Model (IUS)
        TMON    Telemetry MONitoring
        TOD     Training Qperations Director, Time of Day, True of Date
        TOO     Target of Opportunity
        TR      Tape Recorder
        TRI     Tilt Reference Indicator
        TRW     Thompson, Ramo, Wooldrige, Inc.
        TS      Telescope; Telescope System; Telescope Scientist*
        TSC     Translating Science Compartment (An earlier term for the SIM -no longer used.)
        TSP     Twisted Shielded Pair
        TST     Technical Support Team
        TT*     Terrestrial Time
        T/T     Translation Table (BECD)
        TT&C    Telemetry Tracking & Command (IUS)
        TTC     Telescope Thermal Control
        TTCS    Telescope Thermal Control Subsystem
        TTU     Time Transfer Unit
        TVMP    Television Monitor Panel
        TWDS    Twisted Double Shielded
        TWS     Twisted Shielded

        U
        UDE*    User Data Element       
        UDF     Unit Development Folder
        um      micron (micrometer - one-millionth of a meter)
        UPS     User Planning System
        USA     Upper Stage Adapter; United States of America
        USAF    United States Air Force
        USCCS   Universal Spacecraft Clock Calibration System
        USO     Ultra Stable Oscillator
        UVIS*   UV/Ion Shield (on the HRC)
        UT      Universal Time
        UTB     Universal Test Bed
        UTC     Universal Time Coordinated
        UV      Ultraviolet

        V
        VAB     Vehicle Assembly Building
        VATRR   Validation Test Readiness Review
        VCDU    Virtual Channel Data Unit
        VCHP    Variable Conductance Heat Pipes
        VDA     Vacuum Deposited Aluminum
        VCM     Volatile Condensable Materials
        Vdc     Volts direct current
        VDS     Vehicle Dynamics Simulator; Vacuum Deposited Silver
        VDT     Video Display Terminal
        VETA    Verification Engineering Test Article
        VETA-II Verification Engineering Test Article (Second One)
        VPF     Vehicle Processing Facility
        VRCS    Vernier RCS
        VRSD    Verification Requirements and Specification Document
        VSWR    Voltage Standing Wave Ratio
        VTRR    Verification Test Readiness Review

	W
        WAG     Wild-a-- Guess  
        WBS     Work Breakdown Structure
        WDT     Watch Dog Timer
        WETF    Weightless Environment Training Facility
        WG      Working Group
        WG-1    Worm Gear 1
        WG-2    Worm Gear 2
        WORM    Write Once Read Many Times
        WPM     Work Package Managers
        WSGT    White Sands Ground Terminal
        WWW*    World-Wide Web

        X
        XDA     X-Ray Detection Assembly
        XDCR    Transducer
        XDS     X-Ray Detection System (at XRCF)
        XMTR    Transmitter
        XPDR    Transponder
        XPONDER Transponder
        XRC     X-Ray Calibration
        XRCF    X-Ray Calibration Facility
        XRCT    X-Ray Calibration Testing
        XRS     X-ray Spectrometer
        XSPEC* X-ray Spectral Fitting Package
        XTA     X-ray Telescope Assembly
        XTE*    X-ray Timing Explorer
        XUV*    Extreme Ultraviolet

        Z
        ZOE     Zone of Exclusion

Second Acronym List

From TRW Document D22752FE
18 August 1998 DM05

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