| AFB |
Air Force Base |
| AMSAT |
The Radio Amateur Satellite Corporation |
| AOS |
Acquisition of Signal, Appear on Sky |
| ARISS |
Amateur Radio on The International Space Station |
| ARRL |
American Radio Relay League |
| ASL |
Above Sea Level |
| AU |
Astronomical Unit (1 AU = 149 597 871 km) |
| COBE |
Cosmic Background Explorer - US satellite for cosmic microwave background research |
| COSPAR |
The Comittee on Space Research |
| CSA |
Canadian Space Agency |
| Decimal degrees |
Degrees and its parts - angle notation (10.5036°) |
| DMS |
Degrees, Minutes, Seconds - angle notation (10°30'13") |
| DST |
Daylight Saving Time |
| EAFB |
Edwards Air Force Base |
| ECI |
Earth Centered Inertial - coordinate system used for position and velocity vectors of satellite |
| EROS |
Earth Resources Observation System |
| ESA |
European Space Agency |
| ETA |
Estimated Time of Arrival |
| ET |
External Tank |
| EVA |
Extravehicular Activities |
| GEO |
Geosynchronous Earth Orbit |
| GIS |
Geographic Information System |
| GLONASS |
Global Navigation System - Russian GPS equivalent |
| GOES |
Geostationary Operational Environmental Satellite |
| GTO |
Geostationary Transfer Orbit |
| GMT |
Greenwich Meridian Time, see also UTC |
| GMST |
Greenwich Mean Sidereal Time |
| GPS |
Global Positioning System |
| GSO |
Geostationary Orbit |
| GST |
Greenwich Sideral Time |
| HEO |
High Earth Orbit |
| HETE |
High-Energy Transient Experiment |
| HMS |
Hours, Minutes, Seconds - angle notation used for RA output (10h 12m 13s) |
| HST |
Hubble Space Telescope (NORAD# 20580) |
| IARU |
International Amateur Radio Union |
| IAU |
International Astronomical Union |
| IAU 76 |
International Astronomical Union (System of Astronomical Constants - 1976) |
| INPE |
Instituto Nacional de Pesquisas Espaciais (National Space Research Institute, Brazil) |
| ISS |
International Space Station (NORAD# 25544) |
| JAXA |
Japan Aerospace Exploration Agency |
| JD |
Julian Date (date as day number and time as fraction of day, e.g. 2453318.28080) |
| JSC |
Johnson Space Center |
| KSC |
Kennedy Space Center |
| LCL, LT |
Local Time |
| LEO |
Low Earth Orbit |
| LOS |
Loss of Signal |
| LST |
Local Sideral Time |
| LMLV |
Lockheed Martin Launch Vehicle |
| LMST |
Local Mean Sidereal Time |
| MCC |
Mission Control Center |
| MECO |
Main Engine Cutoff |
| MEO |
Mid Earth Orbit, semi-synchronous orbit |
| MET |
Maximum Elevation Time (middle of pass); Mission Elapsed Time |
| MPLM |
Multi-Purpose Logistics Module |
| NASA |
National Aeronautics and Space Administration |
| NASDA |
National Space Development Agency (Japan's organization for commercial launches) |
| NAVSTAR |
Navigation System with Time And Range (original name for GPS) |
| NMEA |
National Marine Electronics Association |
| NOAA |
National Oceanic and Atmospheric Administration |
| NOSS |
Naval Ocean Surveillance System |
| NORAD |
North American Air Defense |
| NSSC |
NORAD Space Surveillance Center |
| PAM |
Payload Assist Module |
| OMS |
Orbital Maneuvering System |
| QTH |
Location of ground station in amateur radio jargon |
| RA |
Right Ascension |
| RAAN |
Right Ascension of the Ascending Node |
| RCS |
Radar Cross Section |
| R/B |
Rocket body |
| SatCat |
Satellite Catalog |
| SDP4 |
Simplified Deep-space Perturbations - prediction model using for satellites with period greater than 225 minutes |
| SGP4 |
Simplified General Perturbations - prediction model using for satellites with period less than 225 minutes |
| SMA |
Semi-Major Axis - half of the longest linear dimension of ellipse |
| SOCRATES |
Satellite Orbital Conjunction Reports Assessing Threatening Encounters in Space |
| SOHO |
The Solar and Heliospheric Observatory |
| SRB |
Solid Rocket Boosters |
| SSME |
Space Shuttle Main Engines |
| STS |
Space Transport System - American space Shuttle program |
| TCA |
Time of Closest Approach |
| TDRSS |
Tracking and Data Relay Satellite System |
| TLE |
Two Line Element - format for storage satellite orbit data necessary for SGP/SDP prediction |
| USSPACECOM |
United States Space Command |
| UTC, UT |
Coordinated Universal Time, mean solar time of Greenwich meridian |
| WGS 84 |
World Geodetic System 1984 |
| ZOE |
Zone of Exclusion |