| 3D | | Three Dimensional |
| A.I. | | Artificial Intelligence |
| ACES | | Advanced Cryogenic Evolved Stage |
| Adv. | | Advanced |
| ATLAST | | Advanced Technology Large-Aperture Space Telescope |
| AU | | Astronomical Unit |
| BEAM | | Bigelow Expandable Activity Module |
| Bio. | | Biological |
| Biomech. | | Biomechanical |
| Bio-Med | | Biomedical |
| CASIS | | Center for the Advancement of Science In Space |
| CATALYST | | Cargo Transportation and Landing by Soft Touchdown |
| Cislunar | | The Space Between the Earth and Moon |
| CNSA | | China National Space Administration |
| Com. | | Commercial |
| Comm | | Communication |
| Cryo. | | Cryogenic |
| CST | | Crew Space Transportation |
| DARPA | | Defense Advanced Research Projects Agency (US) |
| DART | | Double Asteroid Redirection Test |
| E/M | | Earth / Mars |
| EELV | | Evolved Expendable Launch Vehicle |
| EM | | Electromagnetic |
| EMU | | Extravehicular Mobility Unit |
| EOS | | Earth Observing System |
| ESA | | European Space Agency |
| ESO | | European Southern Observatory |
| FT | | Full Thrust |
| G | | Gravity |
| Gen. | | Generation |
| GEO | | Geosynchronous Earth Orbit |
| GPS | | Global Positioning System |
| GRAIL | | Gravity Recovery and Interior Laboratory |
| GSLV | | Geosynchronous Satellite Launch Vehicle |
| H2O | | Water |
| HASTOL | | Hypersonic Airplane Space Tether Orbital Launch |
| He3 | | Helium 3 |
| HEDM | | High Energy-Density Matter |
| HEO | | High Earth Orbit |
| HLV | | Heavy Lift Vehicle |
| ILN | | International Lunar Network |
| In Situ | | On Site |
| IRIS | | Interface Region Imaging Spectrograph |
| ISRO | | Indian Space Research Organization |
| ISRU | | In Situ Resource Utilization |
| ISS | | International Space Station |
| ITS | | Interplanetary Transport System |
| JAXA | | Japan Aerospace Exploration Agency |
| JUICE | | Jupiter Icy Moon Explorer |
| KW | | Kilowatt |
| L/D | | Lift/Drag Ratio |
| L1 | | Lagrange Point 35K Miles From Moon to Earth |
| L2 | | Lagrange Point 40K Miles Beyond Moon |
| L4 | | Lagrange Point 240K Miles Preceding Moon |
| L5 | | Lagrange Point 240K Miles Following Moon |
| LADEE | | Lunar Atmosphere Dust and Environment Explorer |
| LEO | | Low Earth Orbit |
| LLOX | | Lunar Liquid Oxygen |
| Mag. | | Magnetic |
| MAVEN | | Mars Atmosphere and Volatile Evolution Mission |
| MDRE | | Mass Driver Reaction Engine |
| MetNet | | Meteorology Network |
| Mfg. | | Manufacturing |
| MMU | | Manned Maneuvering Unit |
| MMW | | Multi-Megawatt |
| MPCV | | Multi Purpose Crew Vehicle |
| MPR | | Mars Pressurized Rover |
| MR | | Medium Range |
| MW | | Mini-Research Module |
| MXER | | Momentum-Exchange / Electrodynamic-Reboost |
| NASA | | National Aeronautics and Space Administration |
| NEO | | Near Earth Object |
| Ops | | Operations |
| OTV | | Orbital Transfer Vehicle |
| P | | Pressure |
| PLATO | | Planetary Transits and Oscillations Of Stars |
| PTV | | Passenger Transport Vehicle |
| RLV | | Reusable Launch Vehicle |
| RTG | | Radioisotope Thermoelectric Generator |
| SELENE | | Selenological and Engineering Explorer |
| SETI | | Search for Extraterrestrial Intelligence |
| SLS | | Space Launch System |
| S-M-L | | Small-Medium-Large Size Designation |
| SpaceX | | Space Exploration Technologies |
| SR | | Short Range |
| SSP | | Space Solar Power |
| STV | | Space Transfer Vehicle |
| UDM | | Universal Docking Module |
| ULA | | United Launch Alliance |
| Univ. | | University |
| US | | United States |
| V2 | | Second Version |
| VASIMR | | Variable Specific Impulse Magnetoplasma Rocket |
| VR | | Virtual Reality |
| WFIRST | | Wide Field Infrared Survey Telescope |
| XS1 | | Experimental Spaceplane 1 |
