| G&A | general and administrative |
| G&C | ground rules and constraints |
| G&C | guidance and control |
| G&CEP | guidance and control equipment performance |
| G&CI | guidance and control integration |
| G&N | guidance and navigation |
| G&NS | guidance and navigation system |
| G-A | ground to air |
| G-G | ground to ground |
| G-II | Gulfstream II (Shuttle training aircraft) |
| G-MEM | GPC memory |
| G-V | gravity-velocity |
| G/A | ground to air |
| G/A/G | ground to air to ground |
| G/AIT | ground/airborne IGS terminal |
| G/C | guidance and control |
| G/E | graphite-epoxy |
| G/G | ground to ground |
| G/N | general notes |
| G/S | glide slope |
| G/T | gain versus temperature |
| G/T | ratio of antenna gain to receiver noise temperature |
| G/W | gateway |
| GA | glide angle |
| GA | ground antenna |
| GA | gyro assembly |
| GA&CS | ground acquisition and command station |
| GAC | Grumman Aerospace Corporation |
| GAC | ground attitude control |
| GACU | ground air conditioning unit |
| GACU | ground avionics cooling unit |
| GADG | gravity or acceleration due to gravity |
| GAEC | Grumman Aircraft Engineering Corporation |
| GAIN | graphic aids for investigating networks |
| GAO | General Accounting Office |
| GAP | GOAL automatic procedure |
| GAPL | group assembly parts list |
| GAS | getaway special |
| GASD | Government Aerospace Systems Division (Harris Corporation) |
| GASP | General Ascent Trajectory and Sizing Program |
| GASPI | gimbal angle, surface position indicator |
| GATE | generic automatic test equipment |
| GATP | ground acceptance test procedure |
| GATP | ground article test procedure |
| GATT | gate-assisted turnoff thyristor |
| GAX | GN&C annunciation interface |
| GBD | Government Business Division |
| GBD | global burst detector |
| GBI | Grand Bahama Island |
| GBL | government bill of lading |
| GBL | ground-based laser |
| GBOTV | ground-based OTV |
| GBR | glass bead rating |
| GBR | ground-based radar |
| GBS | ground-based software |
| GBSS | ground-based surveillance system |
| GBT | gyro bias calibration value |
| GC | gas chromatography |
| GC | gigacycle (1,000 megacycles) |
| GC | gimbal case |
| GC | ground computer |
| GC | ground contact |
| GC | ground control |
| GC | ground controller |
| GC | guidance computer |
| GC | guidance control |
| GC | gyrocompass |
| GCA | ground-controlled approach |
| GCA | guidance coupler assembly |
| GCC | Ground Control Center |
| GCC | ground communications coordinator |
| GCCC | Ground Control Computer Center |
| GCCO | ground control checkout |
| GCD | greatest common divisor |
| GCD | gyrocompass, desired cluster orientation |
| GCDC | ground checkout display and control |
| GCDS | ground checkout display and control system |
| GCE | GPS cargo element |
| GCF | greatest common factor |
| GCF | ground communications facility |
| GCHX | ground cooling heat exchanger |
| GCI | ground-controlled interception |
| GCID | ground computer interface device |
| GCIL | ground command interface logic |
| GCIL | ground control interface logic |
| GCILC | ground command interface logic controller |
| GCILU | ground control interface logic unit |
| GCL | ground control landing |
| GCL | ground coolant loop |
| GCN | GIRD change notice |
| GCN | ground communications network (A/G worldwide net) |
| GCN | ground control network |
| GCO | ground checkout |
| GCOS | general computer operational system |
| GCOS | ground computer operating system |
| GCP | ground command post |
| GCP | group command post |
| GCR | ground-controlled radar |
| GCR | group-coded recording |
| GCS | ground communications system |
| GCS | ground control station |
| GCS | guidance cutoff signal |
| GCTS | gas component test stand |
| GCTS | ground communication tracking system |
| GCU | general control unit |
| GCU | generator control (regulator) unit |
| GCU | ground cooling unit |
| GCU | gyro coupling unit |
| GDA | General Dynamics Astronautics |
| GDA | gimbal drive actuator |
| GDA | gimbal drive assembly |
| GDBS | generalized data base system |
| GDC | General Dynamics Corporation |
| GDC | gyro display coupler |
| GDCA | General Dynamics Convair Aircraft |
| GDDM | graphical data display manager |
| GDMS | generic data management system |
| GDMS | ground data management system |
| GDOP | geometric dilution of precision |
| GDP | generalized documentation processor |
| GDR | geophysical data record |
| GDS | Goldstone, California (STDN) |
| GDSD | Ground Data Systems Division |
| GDSM | ground data systems manager |
| GDSO | ground data systems officer |
| GDSSR | GDSD staff support room |
| GE | General Electric |
| GE-AESD | General Electric Aerospace Electronics Systems |
| GE/B | General Electric Burroughs |
| GEA | gimbal electronics assembly |
| GEC | General Electrodynamics Corporation |
| GEDAC | General Electric detection and automatic correction |
| GEM | generic electronics module |
| GEMS | general energy management system |
| GEMS | global emergency missile surveillance |
| GEO | geosynchronous Earth orbit |
| GEODSS | ground-based electro-optical deep-space surveillance |
| GEOMOD | geometric modeler |
| GEOPAUSE | geodetic satellite in polar geosynchronous orbit |
| GEOSEPS | geosynchronous solar electric propulsion stage |
| GERT | graphical evaluation and review technique |
| GESS | Goddard experiment support system |
| GET | ground elapsed time |
| GETI | ground elapsed time of ignition |
| GETL | ground elapsed time of landing (for TIG of abort burn) |
| GETS | ground equipment test set |
| GF | gauge factor |
| GF | government-furnished |
| GF&P | gases, fluids, and propellants |
| GFAE | government-furnished aeronautical equipment |
| GFAE | government-furnished aircraft equipment |
| GFD | government-furnished data |
| GFE | government-furnished equipment |
| GFERD | government-furnished equipment requirement description |
| GFI | government-furnished information |
| GFI | ground fault interrupter |
| GFM | government-furnished material |
| GFP | generalized filter program |
| GFP | government-furnished property |
| GFRP | glass-fiber-reinforced plastic |
| GFRP | graphite-fiber-reinforced plastic |
| GFS | government-furnished software |
| GFTM | generic fluids transfer model |
| GFY | government fiscal year |
| GG | gas generator |
| GG | gravity gradient |
| GGVM | gas generator valve module |
| GHA | Greenwich hour angle |
| GHA | general housekeeping area |
| GHC | ground half-coupling |
| GHE | ground handling equipment |
| GHX | ground heat exchanger |
| GHe | gaseous helium |
| GHz | gigahertz |
| GIA | general-purpose computer interface adapter |
| GIAG | Government-Industry Advisory Group |
| GIBIS | graphical issue-based information system |
| GIC | GPC interface console |
| GIDD | GSE interface definition document |
| GIDEP | government interagency data exchange program |
| GIDEP | government-industry data exchange program |
| GIDS | general-purpose interactive display system |
| GIE | ground instrumentation equipment |
| GIF | graphics interchange format |
| GIM | generalized information management |
| GIMADS | generic integrated maintenance and diagnostic system |
| GIMADS | generic integrated maintenance diagnostics |
| GIRD | ground integration requirements document |
| GISO | general industry safety order |
| GITG | Ground Interface Technical Group |
| GIWG | Ground Interface Working Group |
| GKS | graphics kernel system |
| GLAADS | gun low-altitude air defense system |
| GLC | generator line contractor |
| GLCM | ground-launched cruise missile |
| GLLD | ground locator laser designator |
| GLOW | gross lift-off weight |
| GLOW | ground lift-off weight |
| GLP | GOAL language processor |
| GLS | ground launch sequencer |
| GM | gaseous mixture |
| GM | geometric mean |
| GM | ground mobile |
| GMAL | General Electric Macro Assembly Language |
| GMAW | gas metal arc welding |
| GMCC | Ground Mobile Control Center |
| GMCL | ground measurements command list |
| GME | gimbal module electronics |
| GMEM | GPC memory |
| GMF | ground module force |
| GMIL | KSC STDN station |
| GMIP | government mandatory inspection point |
| GMIS | GSSC management information system |
| GMIS | ground STDN management information system |
| GML | general measurement loop |
| GMLCC | Ground Mobile Launch Control Center |
| GMM | geometrical math model |
| GMN | Gorman (TACAN station) |
| GMT | Greenwich mean time |
| GN | ground network |
| GN&C | guidance, navigation, and control |
| GN&CS | guidance, navigation, and control subsystem |
| GNC | guidance and navigation computer |
| GNC | guidance, navigation, and control |
| GNCFTS | GN&C flight test station |
| GNCIS | GN&C integration simulator |
| GNCS | guidance and navigation control system |
| GNCSIM | GN&C simulation |
| GNCTS | GN&C test station |
| GNE | guidance and navigational electronics |
| GNIC | G&N indicator control |
| GNP | gross national product |
| GNS | guidance and navigation simulator |
| GNS | guidance navigation system |
| GO | general order |
| GOAL | ground operations aerospace language |
| GOASEX | Gulf of Alaska Seasat Experiment |
| GOC | ground operations coordinator |
| GOCA | ground operations control area |
| GOCO | government-owned, contractor-operated |
| GOE | ground operating equipment |
| GOE | ground outfitting equipment |
| GOES | geostationary operational environment satellite |
| GOES | geosynchronous operational environmental satellite |
| GOM | KSC ground operations manager at DFRF or WSMR |
| GOMMS | ground operations and material management system |
| GOMS | ground operations management system |
| GOP | Ground Operations Panel |
| GOP | ground operations plan |
| GOPG | Ground Operations Planning Group |
| GOR | ground operations review |
| GORD | ground operations requirements document |
| GORP | Ground Operations Review Panel |
| GORP | ground operations requirements plan |
| GORR | ground operation readiness review |
| GORS | ground observer RF system |
| GOS | ground operations system |
| GOSP | ground operational support plan |
| GOSRP | ground operational support requirements plan |
| GOSS | ground operational support system |
| GOTS | government off the shelf |
| GOWG | Ground Operations Working Group |
| GP | general publication (KSC) |
| GP | general-purpose |
| GP | government property |
| GPA | general-purpose amplifier |
| GPAS | general-purpose airborne simulator |
| GPBIM | general-purpose buffer interface module |
| GPC | gel permeation chromatograph |
| GPC | gel permeation chromatography |
| GPC | general-purpose computer |
| GPC | gyro pulse count |
| GPCB | GOAL program control block |
| GPCIPL | general-purpose computer initial program load |
| GPD | gimbal position display |
| GPI | gimbal position indicator |
| GPI | ground position indicator |
| GPIO | general-purpose input and output |
| GPL | GOAL processing language |
| GPL | general-purpose laboratory |
| GPME | general-purpose mission equipment |
| GPNDS | global positioning and nuclear detection system |
| GPO | Government Printing Office |
| GPRN | GOAL test procedure release notice |
| GPRP | government production research property |
| GPS | Global Positioning System (Navstar) |
| GPS | RX GPS user receiver |
| GPS | general processing subsystem |
| GPS | ground power supply |
| GPS | ground processing simulation |
| GPSCP | GPS computer program |
| GPSS | general-purpose simulator system |
| GPSS | general-purpose system simulator |
| GPTE | general-purpose test equipment |
| GPU | ground power unit |
| GPUR | GOAL test procedure update request |
| GPVS | general-purpose visual simulator |
| GR | ground rule |
| GRACE | ground radar calibration equipment |
| GRD | ground detector |
| GRE | Gamma Ray Explorer |
| GRID | graphic retrieval and information display |
| GRNC | group not counted |
| GRO | Gamma Ray Observatory |
| GRS | global receiving system |
| GRTLS | glide return to launch site |
| GS | II Generalized System II |
| GS | gas servicer |
| GS | generalized system |
| GS | glide slope |
| GS | ground speed |
| GS | ground station |
| GS | ground system |
| GSA | General Services Administration |
| GSAT | geosynchronous satellite |
| GSCU | ground service cooling unit |
| GSDL | Ground Software Development Laboratory |
| GSDS | Goldstone duplicate standard (standard DSIF equipment) |
| GSE | government support equipment |
| GSE | ground servicing equipment |
| GSE | ground support equipment |
| GSE&I | general systems engineering and integration |
| GSEL | ground support equipment list |
| GSERD | ground support equipment recommendation data |
| GSF | gyro scale factor |
| GSFC | Goddard Space Flight Center |
| GSI | glide slope indicator |
| GSI | government source inspection |
| GSIG | Ground Systems Integration Group |
| GSIU | ground standard interface unit |
| GSLS | ground station link survivability |
| GSO | Ground Support Office |
| GSO | ground support operations |
| GSO | ground systems operations |
| GSP | ground safety plan |
| GSP-R | guidance signal processor-repeater |
| GSPF | Ground Software Production Facility (LPS) (FR 2 KSC) |
| GSPO | Ground Systems Project Office (JSC) |
| GSR | galvanic skin response |
| GSS | geosynchronous space station |
| GSS | government systems sector |
| GSS | ground support software |
| GSS | ground support system |
| GSSC | General Systems Simulation Center (NASA) |
| GSSC | ground support simulation computer |
| GSSF | general service stock fund |
| GSSI | ground support system integration |
| GSSI&C | ground support systems installation and checkout |
| GSSI&C | group support systems integration and checkout |
| GST | ground system test |
| GSTAR | Saudi Arabian communications satellite |
| GSTDN | ground space flight tracking and data network |
| GSTDN | ground spacecraft tracking and data network |
| GSTP | ground system test procedure |
| GSTS | ground-based surveillance and tracking system |
| GSTS/BM | ground-based surveillance and tracking sagement |
| GSU | gas servicer unit |
| GSV | glove stop valve |
| GSVOO | ground station visibility of orbiting objects |
| GSVP | ground support verification plan |
| GT | ground team |
| GT | ground test |
| GT | gyro torque |
| GT&A | ground test and acceptance |
| GTA | gas tungsten arc |
| GTA | ground test access |
| GTA | ground test article |
| GTA | ground test assembly |
| GTA | ground torquing assembly |
| GTAW | gas tungsten arc welding |
| GTC | glycol trim console |
| GTC | ground test conductor |
| GTCU | ground thermal conditioning unit |
| GTE | General Telephone and Electronics |
| GTF | ground test facility |
| GTI | Grand Turk Island |
| GTI | ground test instrumentation |
| GTLV | government-furnished target launch vehicle |
| GTM | ground team manager |
| GTM | ground test missile |
| GTM | ground test motor |
| GTO | generic technical order |
| GTO | geosynchronous transfer orbit |
| GTP | general test plan |
| GTRI | Georgia Tech Research Institute |
| GTS | GN&C test station |
| GTS | GNS test station |
| GTS | general test support |
| GTS | guidance test station |
| GTT | group technology time |
| GTU | glycol trim unit |
| GTV | ground test vehicle |
| GTV | ground transport vehicle |
| GTVI | gimbal angle and translational velocity indicator |
| GUCP | ground umbilical carrier plate |
| GUIDO | guidance officer |
| GUL | GSE utilization list |
| GUSB | guided, unified S-band |
| GVL | Ground Vibrations Laboratory |
| GVO | Gaviota (TACAN station) |
| GVSC | generic VHSIC spacecraft computer |
| GVT | ground vibration test |
| GVTA | ground vibration test article |
| GW | gateway |
| GW | gross weight |
| GWA | general work area |
| GWM | Guam (STDN) |
| GWT | ground winds tower |
| GYM | Guaymas, Mexico (remote site) |
| GaAs | gallium arsenide |
| GeV | giga electron volt |
| Gr/Al | graphite-aluminum |
| Gr/Ep | graphite-epoxy |
| g | gravity |
| gph | gallons per hour |
| gpm | gallons per minute |
| gps | gallons per second |