Did you ever wonder what those strange conglomerations of letters meant? Here's your chance to find out what those NASA acronyms stand for. About Space and Astronomy presents the Guide to NASA Acronyms. This page lists acronyms starting with E. For others, click on the appropriate letter above or below.

[E]

E: East
E LACS: Extended Life Attitude Control System
E LSC: Earth Landing Sequence Controller
E LSS: Emergency Life Support System
E&D: Engineering and Development
E&D: Engineering and DeveloPment Directorate (JSC)
E-E: End-to-End
E-MUX: Electrical Multiplex
E-P: Electron/Proton
E/0-ims: E/0-Information Management System
E/C: Encoder/Coupler
E/L: Entry/Landing
E/M: Engineering Model
E/O: Engineering/Operations
E/W: Energy to Weight Ratio
E/W: Energy Over Weight
EA: Electronic Assembly
EA: Each
EA: Elevation Angle
EAC: Energy Absorbing Capacity
EAC: Estimate at Completion
EAD: ElectricallY Alterable Device
EADI: Electronic Attitude Director Indicator
EAFB: Ellington Air Force Base
EAFB: Elgin Air Force Base
EAFB: Edwards Air Force Base
EAFB: Edwards Air Force Base
EAM: Electrical Accounting Machine
EAR: Engineering AnalYsis Report
EAS: Equivalent Air Speed
EAS: Equivalent airspeed
EAT: Environmental Acceptance Test
EB: Emergency Box
EB: Electronic Beam
EBC: Emulated Buffer COMPuter
EBCDC: Extended Binary Coded Decimal
EBD: Eyeballs Down (+GZ)
EBI: Eyeballs in (+GX)
EBL: Eyeballs Left (+GY)
EBO: Eyeballs Out (-GX)
EBR: Eyeballs Right (-GY)
EBS: Emergency Breathing Subsystem
EBU: Eyeballs Up (-GZ)
EBW: Exploding Bridge Wire
EBW: Electron Beam Welding
EC: Element Contractor
EC: Engine Control
EC: Engine Cutoff
EC: Events Coupler
EC: Essentiality Code
EC: Experiment Computer
EC: Events Controller
ECA: Engineering Change Analysis
ECA: Electronics Control Assembly
ECA: Epoxy Curing Agent
ECAS: Experiment Computer Application Software
ECB: Engineering Change Board
ECB: Event Control Block
ECB: Events Control Buffer
ECC: Engineering Critical Component
ECC: Engineering Change Control
ECCB: Engineering Change Control Board
ECD: Engineering Control Drawing
ECD: Estimated Completion Date
ECEP: Experiment Checkout Equipment Processor
ECF: Equivalency Capability File
ECF: Element Charge Factor
ECG: Electrocardiogram
ECG: Electrocardiograph
ECI: Earth Centered Inertia (inertials)
ECIO: Experiment Computer Input/Output
ECL: Entry Closed Loop
ECLS: Environmental Control and Life Support
ECLSS: Environmental Control and Life Support System
ECLSS: Environmental control and life support system
ECN: Engineering Change Notice
ECO: Engine Cutoff
ECO: Engine Combustion
ECO: Engineering Change Order
ECOS: Experiment Computer Operating System
ECP: Explicitly Coded Program
ECP: Engineering Change Proposal
ECP: Engineering Control Proposal
ECP: Engineering Change Program
ECR: Engineering Change Request
ECRA: Engineering Change Request/Authorization
ECS: Environmental Control System (Subsystem)
ECS: Engine Control SYstem
ECU: Environmental Control Unit
ECU: Electronic Coupling Unit
ECU: Electrical control unit
ED: Explosive Device
ED: Edge Distance
ED: Engineering Directive
ED: Edit
EDA: Elevation Drive Assembly
EDA: Electronic DisPlay Assembly
EDB: Environmental Data Book
EDC: Engineering Design Change
EDC(M): Electrochemical DePolarized CO (Module)
EDCP: Engineering Design Change ProPosal
EDDR: Electron DiPole-DiPole Reservoir
EDF: Engineering Data File
EDLN: Engineering DeveloPment Logic Network
EDP: Electonic Data Processing
EDPE: Electronic Data Processing EquiPment
EDPM: Electronic Data Processing Machine
EDR: Engineering Design Review
EDS: Emergency Detection System
EDS: Electrical Distribution System
EDT: Explosive Device System
EDT: Eastern Daylight Time
EDU: Engineering DeveloPment Unit
EDV: Electronic Depressurizing Valve
EDW: Edwards (TACAN Station)
EDW: "Edwards Air Force Base, CA (Deorb OPT site)"
EE: End Effector
EECOM: "EleCtrical, Environmental, and Communications"
EECOM: "Electrical, Environmental, Consumables, and Mechanical"
EECOM: Systems (MPSR)
EED: Electro (Electrical) Explosive Device
EED: Electroexplosive device
EEE: "Electronic, Electrical, Electromechanical"
EEEU: End Effector Electronics Unit
EEG: Electroencephalogram
EEH: EMU Electrical Harness
EEIS: End-to-End Information System
EEL: Electrical Equipment List
EEM: Earth Entry Module
EENT: "Eye, Ear, Nose, and Throat"
EES: Emei@gency Ejection Suits
EES: Ejection Escape Suit
EES: Escape ejection suit
EET: Entry Elapsed Time
EETB: Electronic Electrical Termination Building
EEVT: Electrophoresis Equipment Verification Test
EFA: Experiment Flight Applications
EFCS: Earth Fixed Coordinate System
EFF: Efficiency
EFFGRO: Efficient Growth (Computer Program)
EFP: ESA Furnished Property
EFTO: Encrypted for Transmission Only
EG: Entry Guidance
EGA: Evolved Gas Analysis
EGC: Experiments Ground Computer
EGF: "Electrical, Grapple Fixture"
EGIL: "Electrical, General Instrumentation, and Lighting E"
EGRET: Energetic Gamma Ray Explorer Telescope
EGRS: Egress
EGSE: Electrical Ground Support Equipment
EGT: Elapsed Ground Time
EGT: Estimated Ground Time
EGT: Exhaust Gas Temperature
EGUN: Fast Pulse Electron Gun
EH/M: Extension Hose/Moi!thpiece
EHC: Electrical Heating Control
EHF: Extremely High Frequency
EHOT: External Hydrogen/Oxygen Tank
EHP: Effective Horsepower
EHP: Electrical Horsepower
EHR: Earned Hour Ratio
EHS: Environmental Health Services
EHX: Experiment Dedicated Heat Exchanger
EI: Entry interface
EIA: Electrical Industries Association
EIASN: End Item Assembly Sequence Number
EIC: Experimental Intercom
EID: End Item Documentation
EIDP: End Item Data Package
EIFA: Element Interface Functional Analysis
EIR: Environmental Impact Report
EIRP: Effective lsotropic Radiated Power
EIS: Electrical Integration SYstem
EIS: Environmental Impact Statement
EIS: End Item Specification
EIS: Extended Instruction Set
EIT: Entry Interface Time
EIU: Engine Interface Unit
EIU: Engine interface unit
EIVT: Electrical and Instrumentation Verification Test
EIVT: Electrical Interface Verification Test
EIVT: Electronic Installation Verification Test
EJN: Ejection
EKG: Electrocardiogram (Record)
EKG: Electrocardiograph (Instrument)
EL: Elastic Limit
EL: Elevation Angle
EL: Elevate
EL: Electroluminescent
EL MECH: Electromechanical
ELB: Elbow
ELDISC: Electrical Disconnect
ELDV: Electrically Operated Depressurization Valve
ELEC: Electronic
ELEC: Electric
ELECT: Electrical
ELECTR: Electronics
ELEV: Elevon
ELF: Extremely Low Frequency (1 Hz to 3 kHz)
ELINT: Electromagnetic Intelligence
ELMCH: Electromechanical
ELMS: Elements
ELMS: Elastic Loop Mobility System
ELS: Earth Landing System (Subsystem)
ELS: Eastern Launch Site
ELS: Elevon Load System
ELT: Emergency Locator Transmitter
ELV: Earth Launch Vehicle
ELV: Electrically Operated Valve
ELV: Expendable Launch Vehicle
ELVN: Eleven
EM: Exception Monitor
EM: Emergency
EM: Engineering Model
EMA: Electromagnetic Analysis
EMC: Electromagnetic Compatibility
EMCC: Emergency Mission Control Center
EMCD: Electro-Mechanical Control Diagram
EMCI: Engineering Model Configuration Inspection
EMD: Entry Monitor Display
EMEC: Electromagnetic Effects Capability
EMEC: Electromagnetic Effects Compatibility
EMER: Emergency
EMES: "Electriral, Mechanical, and Environmental Systems"
EMF: Electromagnetic Force
EMF: Electromotive Force
EMG: Electromyograph(gram)
EMG: Surface Electromyograms
EMI: Electromagnetic Interference
EMIS: Emission
EMK: Emergency Medical Kit
EMK: Emergency medical kit
EML: Electromagnetic Laboratory
EMN: Engineering Management Network
EMON: Exception Monitoring
EMP: Electromagnetic Pulse
EMP: EquiPment Mounting Plate
EMPGS: Electrical/Mechanical Power Generation SubsYstem
EMR: Engine Mixture Ratio
EMRL: Equipment Maintenance Requirements List
EMS: Entry Monitor Subsystem
EMS: Engineering Master Schedule
EMS: Entry Monitoring system
EMS: Electromagnetic Susceptibility
EMSS: Electromagnetic Servoactuator SYstem
EMT: Electro-Mechanical Test
EMU: Extravehicular Mobility Unit
EMU: Engineering Model Unit
EMU: Extended Memory Unit
EMU: Extravehicular mobility unit
EMU-TV: Extravehicular MobilitY Unit - Television
ENA: Enable
ENC: Encode
ENCD: Encode
ENCL: Enclose
END EFF: End Effector
ENDF: Evaluated Neutron Data File
ENG: "Engine, Engineer"
ENG: ElectronYstagnogram
ENGR: Engineer
ENGRG: Engineering
ENT: Entry
ENVIR: "Environment, Environmental"
EO: Earth Orbit
EO: Earth Observation
EOC: End of Contract
EOC: Engine Order Capability
EOC: Engine-out Capability
EOD: Estimated on Dock
EOD: Explosive Ordnance Disposal
EODB: End of Data Block
EOF: End of File
EOG: Electroculogram
EOHT: External Oxygen and Hydrogen Tanks
EOI: Earth Orbit Insertion
EOL: End of Line
EOM: Equations of Motion
EOM: Engineering Operations Manual
EOM: End of Mission
EOM: End of Message
EOMF: End of Minor Frame
EOP: Emergency Oxygen Pack
EOP: Experiments of Opportunity
EOP: Earth and Ocean Physics
EOPAP: Earth and Ocean Physics Application Program
EOPO: Equal Opportunity Program Office
EOR: Earth Orbit Rendezvous
EOS: Earth Orbit Shuttle
EOS: Emergency Oxygen Supply
EOS: Emergency Oxygen System
EOS: Extended Operating System
EOS: Earth Observation Satellite
EOT: End of Tape
EOT: End of Transmission
EOW: Energy over Weight
EP: Elbow Pitch
EP: Environmental Protective Plan
EP: Electrical Power
EPA: Environmental Protection Agency
EPC: Error Protection Code
EPC: External Power Contractor
EPCDC: "Electrical Power Conditioning, Distribution, and"
EPCDC: Control
EPD: Emergency Procedures Document
EPD: Electrical Power Distribution
EPDB: Electrical Power Distribution Box
EPDB: Experiment Power Distribution Box
EPDC: Electrical Power Distribution and Control
EPDCS: Electrical Power Distribution and Control System
EPDS: Electrical Power and Distribution Subsystem
EPDS: Electrical Power Distribution System
EPDS: Electrical power distribution subsystem
EPDU: Electrical power distribution unit
EPG: Electrical Power Generator
EPL: Electrical Power Level
EPL: "Electronic, Electrical, and Electromechanical Parts"
EPL: List
EPL: Emergency Power Level
EPMS: Engineering Performance Management System
EPO: Element Project Office
EPOC: External Payload Operations Center
EPPS: Electrical Power/Pyro Sequential System
EPR: Engine Pressure Ratio
EPRN: Emergency Program Release Notice
EPROM: Erasable Programmable Read Only Memory
EPS: Electrical Power System (Subsystem)
EPS: ExPerimental Power Supply
EPS: Electrical power system
EPSP: Experiment Power Switching Panel
EPT: Emergency Procedure Trainer
EPT: Ethylene Propylene Terpolymer
EPTU: Events per Time Unit
EPWG: Environmental Projects Working Group
EQ: Equivalent
EQE: Event Queue Element
EQL: Equal
EQUIP: Equipment
EQUIV: Equivalent
ER: Explanation Report
ERA: Electrical Replaceable Assembly
ERAP: Earth Resources Aircraft Program
ERB: Engineering Review Board
ERBE: Earth Radiation Budget Experiment
ERBS: Earth Radiation Budget Satellite
ERC: Event Recorder
ERCA: Electrochemically Regenerable CO2Absorber
EREP: Earth Resources Package
ERG: Ergometer
ERNO: "of European Consortium, VFW-Fokker-Mannheim,"
ERNO: Germany (SPacelab Contractor)
ERO: Engineering Release Operations
ERP: Effected Radiative Power
ERP: Eye Reference Point
ERP: Effective Radiation Power
ERPM: Engineering Requirements and Procedures Manual
ERR: Error
ERR CNTR: Error Counter
ERRC: Expendability/Recoverability/Repair Capability
ERS: Engineering Release System
ERS: Entry and Recovery Simulation
ERS: Earth Recovery Subsystem
ERSI: Elastomeric Reusable Surface insulation
ERSIR: Earth Resources Shuttle Imaging Radar
ERTS: Earth Resources Technology Satellite
ERU: Earth Rate Unit
ERV: Expiratory Reserve Volume
ES: Experiment Segment
ES: Escape System
ESA: Engineering SuPPly Area
ESA: Engineering SuPPort Assembly
ESA: European Space Agency
ESA: ExPlosive Safe Area
ESA: European Space Agency
ESA: Explosive safe area (KSC)
ESB: Essential Switching Box
ESC: Escape
ESCA: Electron Spectroscopy for Chemical Analysis
ESCU: Extended Service and Cooling Umbilical
ESD: Experiment Systems Division
ESD: Emergency Shutdown
ESDAC: "European Space Data Center (Darmstadt, Germany)"
ESDU: Event Storage and Distribution Unit
ESE: Electrical Support Equipment
ESE: Electronic SuPport Equipment
ESE: EVA Support Equipment
ESF: Explosive Safe Facility
ESI: Electrical System Integration
ESMC: ETR
ESMC: "Eastern Space and Missile Center (formerly AFETR), also"
ESO: Event Sequence Override
ESOC: European Space Operations Center
ESOW: Engineering Statement of Work
ESP: Engine Service Platforms
ESP: Experiment Sensing Platform
ESP: Electroshock Protection
ESPS: Experiment Segment Pallet Simulator
ESR: Effective Sunrise
ESR: Engineering Support Request
ESRIN: European Space Research Institute
ESRO: European Space Research Organization
ESRO: European Space Research Organization
ESS: Environmental Support System
ESS: Essential
ESS: Experiment Subsystem Simulator
ESS: Effective Sunset
ESS: Equipment support section
ESS: Essential
ESSA: Environmental Sciences Services Administration
EST: Eastern Standard Time
EST: Estimate(d)
ESTA: Electronic System Test Equipment
ESTA: Escape System Test Article
ESTEC: European Space Research and Technology Center
ESTEC: European Space Technology Center
ESTL: Electronic Systems Test Laboratory
ESV: Emergency Shutoff Valve
ESVS: Escape System Ventilation System
ESVS: Escape Suit Ventilation System
ESVS: Escape suit ventilation system
ESW: Engine Status Word
ET: Edge Thickness
ET: Elevated Temperature
ET: Event Timer
ET: External Tank
ET: Elapsed Time
ET: External tank
ET-SEP: External Tank Separation
ETA: Environmental Test Article
ETA: Estimated Time of Arrival
ETA: Estimated Time to Acquisition
ETA: Explosive Transfer Assembly
ETA: External Tank Attachment
ETB: Equipment Transfer Bag
ETC: Estimate to Completion
ETC: "Greenbelt, Maryland (STDN Site)"
ETC: Earth Terrain Camera
ETCO: Equipment Transfer/Change Order
ETD: Electrical Terminal Distributor
ETD: Estimated Turnover Date
ETD: External Tank Door
ETE: End-to-End
ETI: Elapsed Time Indicator
ETLOW: External Tank Lift-Off Weight
ETM: ElaPsed Time Meter
ETP: Equipment Test Plan
ETR: Eastern Test Range (ESME preferred)
ETR: Eastern test range
ETROD: Eastern Test Range Operations Directive
ETS: Energy Transfer System
ETS: External Tank System (Subsystem)
ETS: Electrical Test Set
ETSS: External Tank Separation Subsystem
ETVA: External Tank Vent Arm
EU: Electronic Unit
EU: Engineering Units
EU: Experimental Unit
EUROCOMSATE: European Consortium Communications Satellite
EUV: Extreme Ultraviolet
EUVE: Extreme Ultraviolet Explorer
EV: Electron Volts
EV: Expendable Vehicles
EV: Extravehicular
EVA: Earned Value Analysis
EVA: Extravehicular Activity
EVA: Extravehicular activity
EVAL: Earth Viewing Applications Laboratory
EVAL: "Evaluate, Evaluation"
EVAP: Evaporator
EVATA: Extravehicular Activity Translational Aid
EVC: Extravehicular Communications
EVCON: Events Control (Subsystem)
EVCS: Extravehicular Communications System
EVCU: Extravehicular Communications Umbilical
EVD: External Visual Display
EVF: Equipment Visibility File
EVLSS: Extravehicular Life Support System
EVM: Earth Viewing Module
EVMU: Extra Vehicular Mobility Unit
EVO: Engineering Verification Order
EVS: Equipment VisibilitY System
EVS: Extravehicular Suit
EVSC: Extravehicular Suit Communications
EVSS: Extravehicular Space Suit
EVSU: Extravehicular Space Unit
EVT: Engineering Verification Test
EVT: Extravehicular Transfer
EVVA: Extravehicular Visor Assembly
EWA: Estimated Warehouse Arrival
EWE: Emergency Window Escape
EWO: Engineering Work Order
EWR: Engineering Work Request
EX: Executive Management Office (KSC Directorate)
EXC: Experiment Computer
EXCH: Exchange
EXEC: Execute
EXH: Exhaust
EXO: Experiment Operator (in Spacelab)
EXP: Exposure
EXP: Expand
EXP: Experiment
EXPEN: Expendable
EXT: Experiment Terminal (Operator Console on Spacelab)
EXT: Extension
EXT: External
EXTD: Extend
EXTER: External
EXTGH: Extinguish
El: End Item
El: Engineering Instruction
El: Entry Interface
El: Environmental Impact
El: Electronic Interface
El: Electromagnetic Interference

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