| AAS | American Astronomical Society |
| ACE | Advanced Composition Explorer |
| ACR | anomalous cosmic ray |
| AFOSR | Air Force Office of Scientific Research |
| AFRL | Air Force Research Laboratory |
| AFWA | Air Force Weather Agency |
| AGS | Atmospheric and Geospace Sciences Division |
| AGU | American Geophysical Union |
| AIA | Atmospheric Imaging Assembly |
| AIM | atmosphere-ionosphere-magnetosphere (system); Aeronomy of Ice in the Mesosphere |
| (mission) | |
| AIMI | atmosphere-ionosphere-magnetosphere interactions |
| AIP | American Institute of Physics |
| AMISR | Advanced Modular Incoherent Scatter Radar |
| AMPERE | Active Magnetosphere and Planetary Electrodynamics Response Experiment |
| AMPTE | Active Magnetospheric Particle Tracer Explorers |
| AO | Announcement of Opportunity |
| APS | American Physical Society; active pixel sensor |
| AST | Division of Astronomical Sciences |
| ATST | Advanced Technology Solar Telescope |
| AU | astronomical unit |
| AURA | Association of Universities for Research in Astronomy |
| AXAF | Advanced X-ray Astrophysics Facility |
| BARREL | Balloon Array for RBSP Relativistic Electron Losses |
| BBSO | Big Bear Solar Observatory |
| CADRE | CubeSat Investigating Atmospheric Density Response to Extreme Driving |
| CAREER | Faculty Early Career Development |
| CASSIOPE | Cascade, Small Satellite, and Ionospheric Polar Explorer |
| CATE | cost and technical evaluation |
| CAWSES | Climate and Weather of the Sun-Earth System |
| CCD | charge-coupled device |
| CCE | Charge Composition Explorer |
| CCMC | Community Coordinated Modeling Center |
| CDC | Concept Design Center |
| CEDAR | Coupling, Energetics, and Dynamics of Atmospheric Regions |
| CHAMP | Challenging Mini-Satellite Payload |
| CINDI | Coupled Ion Neutral Dynamic Investigation |
| CINEMA | CubeSat for Ions, Neutrals, Electrons, Magnetic Fields |
| CIR | corotating interaction region |
| CISM | Center for Integrated Space Weather Modeling |
| CME | coronal mass ejection |
| CMOS | Complementary Metal Oxide Semiconductor |
| C/No | carrier signal-to-noise strength |
| C/NOFS | Communications/Navigation Outage Forecasting System |
| COBE | Cosmic Background Explorer |
| CoBRA | Complexity Based Risk Assessment |
| COSMIC | Constellation Observing System for Meteorology, Ionosphere, and Climate |
| COSMO | Coronal Solar Magnetism Observatory |
| COTS | commercial off-the-shelf |
| CPU | central processing unit |
| CRRES | Combined Release and Radiation Effects Satellite |
| CSSWE | Colorado Student Space Weather Experiment |
| DASI | distributed array of small instruments |
| DC | direct current |
| DICE | Dynamic Ionosphere Cubesat Experiment |
| DLR | German Aerospace Center |
| DMSP | Defense Meteorological Satellites Program |
| DOD | Department of Defense |
| DOE | Department of Energy |
| DRIVE | Diversify, Realize, Integrate, Venture, Educate |
| DSCOVR | Deep Space Climate Observatory |
| DYNAMIC | Dynamical Neutral Atmosphere-Ionosphere Coupling (mission) |
| EASCO | Earth-Affecting Solar Causes Observatory |
| ECT | Energetic Particle, Composition, and Thermal Plasma Suite |
| EIA | equatorial ionization anomaly |
| EISCAT | European Incoherent Scatter Scientific Association |
| ELaNa | Educational Launch of Nanosatellites |
| ENA | energetic neutral atom |
| ENASI | Energetic Neutral Atom Spectroscopic Imager |
| EPO | education and public outreach |
| e-POP | Enhanced Polar Outflow Probe |
| EPP | energetic particle precipitation |
| ESA | European Space Agency |
| ESCAPE | Energetics, Sources and Couplings of Atmosphere-Plasma Escape |
| ETA | equatorial temperature anomaly |
| EUV | extreme ultraviolet |
| EUVI | extreme ultraviolet imager |
| EVE | Extreme Ultraviolet Variability Experiment |
| FAA | Federal Aviation Administration |
| FASR | Frequency-Agile Solar Radiotelescope |
| FAST | Fast Aurora Snapshot |
| FDSS | Faculty Development in Space Science |
| FIREBIRD | Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics |
| FOXSI | Focusing Optics X-ray Spectroscopic Imager |
| FUV | far ultraviolet |
| FWHM | full-width, half-maximum |
| FY | fiscal year |
| GCR | galactic cosmic ray |
| GDC | Geospace Dynamics Constellation |
| GEM | Geospace Environment Modeling |
| GEO | geostationary Earth orbit |
| GI | guest investigator |
| GIC | geomagnetically induced current; ground-induced current |
| GNSS | Global Navigation Satellite Systems |
| GOCE | Gravity Field and Steady-State Ocean Circulation Explorer |
| GOES | Geostationary Operational Environmental Satellite |
| GONG | Global Oscillation Network Group |
| GPS | Global Positioning System |
| GRACE | Gravity Recovery and Climate Experiment |
| GRIPS | Gamma-Ray Imager/Polarimeter for Solar Flares |
| GRIS | Gamma-Ray Imaging Spectrometer |
| GSFC | Goddard Space Flight Center |
| GSRP | Graduate Student Research Program |
| GUVI | Global Ultraviolet Imager |
| GW | gravity waves |
| HAARP | High Frequency Active Auroral Research Program |
| HAO | High Altitude Observatory |
| HEAO | High Energy Astronomy Observatory |
| HEIDI | High Energy Imaging Device |
| HEO | high Earth orbit (above GEO) |
| HF | high frequency |
| HI | Heliospheric Imager |
| HIREGS | High Resolution Gamma-Ray and Hard X-Ray Spectrometer |
| HITDP | Heliophysics Instrument and Technology Development Program |
| HPDE | Heliophysics Data Environment |
| HSC | heliophysics science center |
| HSO | Heliophysics Systems Observatory |
| HSS | high-speed solar wind streams |
| HSW | halo solar wind |
| HTP | Heliophysics Theory Program |
| HXR | hard X-ray |
| IBEX | Interstellar Boundary Explorer |
| IGS | International GNSS Service |
| IGY | International Geophysical Year |
| IHY | International Heliophysical Year |
| IKAROS | Interplanetary Kite-craft Accelerated by Radiation of the Sun |
| IMAGE | Imager for Magnetopause-to-Aurora Global Exploration |
| IMAP | Interstellar Mapping and Acceleration Probe |
| IMF | interplanetary magnetic field |
| IMP | Interplanetary Monitoring Platform |
| IMPACT | In Situ Measurements of Particles and CME Transients |
| INCA | Imaging Neutral Atom Camera |
| INMS | Ion Neutral Mass Spectrograph |
| IR | infrared |
| IRIS | Interface Region Imaging Spectrograph |
| ISCCP | International Satellite Cloud Climatology Project |
| ISEE | International Sun-Earth Explorer |
| ISI | Institute for Scientific Information |
| ISM | interstellar medium |
| ISMF | interstellar magnetic field |
| ISOON | Improved Solar Observing Optical Network |
| ISR | incoherent scatter radar |
| ISS | International Space Station |
| IT | ionosphere-thermosphere |
| ITAR | International Traffic in Arms Regulations |
| ITM | ionosphere-thermosphere-mesosphere |
| IVM | Ion Velocity Meter |
| JAXA | Japan Aerospace Exploration Agency |
| JPL | Jet Propulsion Laboratory |
| L1 | Sun-Earth Lagrangian Point 1 |
| L5 | Sun-Earth Lagrangian Point 5 |
| LANL | Los Alamos National Laboratory |
| LBH | Lyman-Birge-Hopfield |
| LCAS | Low-Cost Access to Space |
| LECP | low-energy charged-particle |
| LEO | low Earth orbit |
| LET | Low Energy Telescope |
| LISM | Local Interstellar Medium |
| LPV | Localizer Performance with Vertical Guidance |
| LT | local time |
| LWS | Living With a Star |
| MAC | Magnetospheric-Atmosphere Coupling (mission) |
| MagCat | Magnetospheric Constellation and Tomography (mission) |
| MagCon | Magnetospheric Constellation (mission) |
| MEDICI | Magnetosphere Energetics, Dynamics, and Ionospheric Coupling Investigation |
| MEMS | microelectromechanical system |
| MESSENGER | Mercury Surface, Space Environment, Geochemistry, and Ranging |
| MHD | magnetohydrodynamic |
| MI | magnetosphere-ionosphere |
| MIDEX | Mid-size Explorer |
| MISTE | Magnetosphere-Ionosphere Source Term Energetics (mission) |
| MIT | magnetosphere-ionosphere-thermosphere |
| MLSO | Mauna Loa Solar Observatory |
| MLT | mesosphere and lower thermosphere |
| MMS | Magnetospheric Multiscale (mission) |
| MO&DA | mission operations and data analysis |
| MODIS | Moderate Resolution Imaging Spectroradiometer |
| MPS | Mathematical and Physical Sciences |
| MREFC | Major Research Equipment and Facilities Construction (program) |
| MRF | Medium-Scale Research Facility |
| MSO | Mees Solar Observatory |
| MWO | Mt. Wilson Observatory |
| NASA | National Aeronautics and Space Administration |
| NCAR | National Center for Atmospheric Research |
| NESDIS | National Environmental Satellite, Data, and Information Service |
| NESSF | NASA’s Earth and Space Science Fellowship (program) |
| NGDC | National Geophysical Data Center |
| NIST | National Institute of Standards and Technology |
| NJIT | New Jersey Institute of Technology |
| NOAA | National Oceanic and Atmospheric Administration |
| NRC | National Research Council |
| NSF | National Science Foundation |
| NSO | National Solar Observatory |
| NST | New Solar Telescope |
| NSWP | National Space Weather Program |
| NuSTAR | Nuclear Spectroscopic Telescope Array |
| NWM | Neutral Wind Meter |
| NWS | National Weather Service |
| OCT | Office of the Chief Technologist |
| OEDG | Opportunities for Enhancing Diversity in the Geosciences (program) |
| ORBITALS | Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite |
| OVSA | Owens Valley Solar Array |
| PARS | Polar Aeronomy and Radio Science |
| PFISR | Poker Flat Incoherent Scatter Radar |
| PI | principal investigator |
| POES | Polar Operational Environmental Satellite |
| P-POD | Poly Picosatellite Orbital Deployer |
| PUI | pickup ion |
| PW | planetary waves |
| QBO | quasi-biennial oscillation |
| RE | Earth radius |
| RS | Sun radius |
| R&A | research and analysis |
| RAX | Radio Aurora Explorer |
| RBSP | Radiation Belt Storm Probe; renamed Van Allen Probes |
| REPT | Relativistic Electron-Proton Telescope |
| REU | Research Experiences for Undergraduates |
| RFI | request for information |
| RHESSI | Ramaty High-Energy Solar Spectroscopic Imager |
| RISR | Resolute Bay Incoherent Scatter Radar |
| ROSES | Research Opportunities in Space and Earth Sciences |
| RPA | Ion Retarding Potential Analyzer |
| SABER | Sounding of the Atmosphere using Broadband Emission Radiometry |
| SALMON | Stand Alone Missions of Opportunities Notice |
| SAMPEX | Solar Anomalous and Magnetospheric Particle Explorer |
| SAPS | subauroral polarization streams |
| SCOSTEP | Scientific Committee on Solar-Terrestrial Physics |
| SDO | Solar Dynamics Observatory |
| SEE | Solar Eruptive Events (mission) |
| SEP | solar energetic particle |
| SFO | San Fernando Observatory |
| SHINE | Solar, Heliosphere and Interplanetary Environment |
| SHP | solar and heliospheric physics |
| SKR | Saturnian Kilometric Radio |
| SM | servicing mission |
| SMD | Science Mission Directorate |
| SMEI | Solar Mass Ejection Imager |
| SMEX | Small Explorer |
| SNOE | Student Nitric Oxide Explorer |
| SNR | signal-to-noise ratio |
| SO | Solar Orbiter |
| SOHO | Solar and Heliospheric Observatory |
| SOLIS | Synoptic Optical Long-term Investigations of the Sun |
| SOON | Solar Observing Optical Network |
| SORCE | Solar Radiation and Climate Experiment |
| SPA | Space Physics and Aeronomy |
| SPARC | Stratospheric Processes and Their Role in Climate |
| SPASE | Space Physics Archive Search and Extract |
| SPD | Solar Physics Division |
| SPI | Solar Polar Imager |
| SPP | Solar Probe Plus |
| SRAG | Space Radiation Analysis Group |
| SRP | solar radiation pressure |
| SR&T | supporting research and technology |
| SSP | solar sail propulsion |
| SSPIS | Solar and Space Physics Information System |
| STE | suprathermal electron |
| STEM | science, technology, engineering, and mathematics |
| STEREO | Solar-Terrestrial Relations Observatory |
| STP | Solar-Terrestrial Probes (program) |
| SuperDARN | Super Dual Auroral Radar Network |
| SUVIT | Solar UV-Visible-IR Telescope |
| SWaC | space weather and climatology |
| SWAP | space, weight, and power |
| SWICS | Solar Wind Ion Composition Spectrometer |
| SWL | Space Weather Laboratory |
| SWMI | solar wind-magnetosphere interactions |
| SWPC | Space Weather Prediction Center |
| SXT | Soft X-Ray Telescope |
| TDRSS | Tracking and Data Relay Satellite System |
| TEC | total electron content |
| TEX | tiny Explorers |
| THEMIS | Time History of Events and Macroscale Interactions during Substorms |
| TIM | Total Irradiance Monitor |
| TIMED | Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics |
| TR&T | Targeted Research and Technology |
| TRACE | Transition Region and Coronal Explorer |
| TRL | technology readiness level |
| TS | termination shock |
| TSI | total solar irradiance |
| TWINS | Two Wide-Angle Imaging Neutral-Atom Spectrometers |
| UARS | Upper Atmosphere Research Satellite |
| UHURU | Small Astronomical Satellite 1, Swahili for Freedom |
| ULDB | Ultra Long Duration Balloon |
| USAF | U.S. Air Force |
| USGS | U.S. Geological Survey |
| USML | U.S. Munitions List |
| UT | universal time |
| UV | ultraviolet |
| UVCS | Ultraviolet Coronagraph Spectrometer |
| V1 | Voyager 1 |
| V2 | Voyager 2 |
| VxO | (domain-specific) virtual observatory |
| WAAS | Wide Area Augmentation System |
| WACCM | Whole Atmosphere Community Climate Model |
| WBS | work breakdown structure |
| WHI | Whole Heliosphere Interval |
| WLC | White Light Coronagraph |
| WPI | wave-particle interaction |
| WSA-Enlil | Wang-Sheely-Arge-Enlil |
| WSO | Wilcox Solar Observatory |