| NESC | National Electrical Safety Code | In English | → Electrical engineering |
| NESDIS | National Environmental Satellite Data and Information Service | In English | → Nature → Spaceflight engineering, astronautics |
| NESP | Naval Extremely high frequency Satellite Program | In English | → Military engineering → Spaceflight engineering, astronautics |
| NESS | National Environmental Satellite Service | In English | → Environment, environmental sciences → Spaceflight engineering, astronautics |
| NEST | Nuclear Emergency Search Team | In English | → Nuclear technology |
| NET | NASA Employee Team | In English | → Spaceflight engineering, astronautics |
| NETA | New Electricity Trading Arrangements | In English | → Commercial law → Electrical engineering |
| NETWEIs | New and Emerging Technologies - Wege zur Erkennung und Implementierung für KMUs | In German | → Research policy |
| NEVS | NASA Equipment Visibility System | In English | → Spaceflight engineering, astronautics |
| NEWS | New Engineering Work Schedule | In English | |
| NEWS | New Engineering Work System | In English | |
| NFS | NASA FAR Supplement | In English | → Spaceflight engineering, astronautics |
| NFS | Nordiska Flaggsällskapet (www.nordicflagsociety.org) = NFS | Nordisk Flaggselskap | In Norwegian = NFS | Nordic Flag Society | In English = NFS | Nordisk Flagselskab | In Danish = NFS | Pohjoismaiden Lippuseura | In Finnish = NFS | Norræna Fánafélagið | In Icelandic |
In Swedish | → Organizations and associations → 6299 |
| NFS | Norræna Fánafélagið (www.nordicflagsociety.org) = (look above) |
In Icelandic | → Organizations and associations → 6299 |
| NFS | Pohjoismaiden Lippuseura (www.nordicflagsociety.org) = (look above) |
In Finnish | → Organizations and associations → 6299 |
| NFS | Nordic Flag Society (www.nordicflagsociety.org) = (look above) |
In English | → Organizations and associations → 6299 |
| NFS | Nordisk Flaggselskap (www.nordicflagsociety.org) = (look above) |
In Norwegian | → Organizations and associations → 6299 |
| NFS | Nordisk Flagselskab (www.nordicflagsociety.org) = (look above) |
In Danish | → Organizations and associations → 6299 |
| NGA | National Geospatial-Intelligence Agency | In English | → Central administration → Spaceflight engineering, astronautics |
| NGT | NASA Ground Terminal | In English | → Spaceflight engineering, astronautics |
| NH&S | Nuclear Hardening and Survivability | In English | → Nuclear technology |
| NHB | NASA Handbook | In English | → Spaceflight engineering, astronautics |
| NICE | Nizhny Novgorod Innovation Center for Energy Saving | In English | → Energy economics |
| NIFES | National Industrial Fuel Efficiency Service | In English | → Energy economics → Vehicle engineering |
| NIFO | Neidentigita Fluganta Objekto = OVNI | Objet Volant Non Identifié | In French = OVNI | Objecte Volador No Identificat | In Catalan = НЛО | Неидентифициран летящ обект | In Bulgarian = OVNI | Objeto Volador No Identificado | In Spanish = UFO | Unidentifiziertes Flugobjekt | In German = UFO | Unidentified Flying Object | In English = UFO | Unknown Flying Object | In English = UFO | Uidentificeret flyvende objekt | In Danish = UFO | Unbekend fleanend objekt | In Frisian = עב"מ | עצם בלתי מזוהה | In Hebrew = OVNI | Oggetto Volante Non Identificato | In Italian = NLO | Neidentificēts lidojošs objekts | In Latvian = UFO | Uidentifisert flygende objekt | In Norwegian = UFO | Uidentifisert flygande objekt | In Nynorsk = NOL | Niezidentyfikowany Obiekt Latający | In Polish = OVNI | Objeto Voador Não Identificado | In Portuguese = OZN | Obiect Zburător Neidentificat | In Romanian = НЛО | Неопознанный летающий объект | In Russian = NLO | Neidentifikovani leteći objekat | In Serbo-Croatian |
In Esperanto | → Spaceflight engineering, astronautics |
| NIFS | National Institute for Fusion Science | In English | → Research institutes → Nuclear, atomic, and molecular physics → Nuclear technology |
| NIFTE | Non-Inertive Feedback Thermofluidic Engine | In English | → Mechanical engineering |
| NIM | Nuclear Instrumentation Module | In English | → Nuclear technology |
| NIMP | Nuclear Instruments and Methods in Physics Research | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NIMS | National Institute for Materials Science (www.nims.go.jp) | In English | → Research institutes → Materials science |
| NIST | National Institute for Standardization and Technology (www.nist.gov) | In English | → Standardization |
| NIST | National Institute of Standards and Technology (www.nist.gov) | In English | → Standardization |
| NISTJ | National Institute of Standards and Technology Journal of Research | In English | → Serial publications, periodicals → Standardization |
| NITLE | National Institute for Technology and Liberal Education | In English | → Education |
| NLO | Neidentifikovani leteći objekat = NIFO, OVNI, НЛО, UFO, עב"מ, NOL, OZN (look above) |
In Serbo-Croatian | → Spaceflight engineering, astronautics |
| NLO | Neidentificēts lidojošs objekts = NIFO, OVNI, НЛО, UFO, עב"מ, NOL, OZN (look above) |
In Latvian | → Spaceflight engineering, astronautics |
| NLR | Nationaal Lucht- en Ruimtevaartlaboratorium | In Dutch | → Research institutes → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| NMAB | National Materials Advisory Board | In English | → Organizations and associations → Materials science |
| NMBS | Nationale Maatschappij der Belgische Spoorwegen (www.b-rail.be) = SNCB | Société Nationale des Chemins de fer Belges | In French |
In Dutch | → Rail transport engineering → Transport and postal services |
| NMCC | National Military Command Center | In English | → Military engineering |
| NMI | NASA Management Instruction | In English | → Management → Spaceflight engineering, astronautics |
| NMI | National Maritime Institute | In English | → Marine research, oceanography → 627 → 6295 |
| NMOS | Negative-Type Metal Oxide Semiconductor | In English | → Electronics |
| NMR | Nuclear Magnetic Resonance = RMN | Résonance Magnétique Nucléaire | In French = RMN | Ressonància Magnètica Nuclear | In Catalan = RMN | Risonanza Magnetica Nucleare | In Italian = תמ"ג | תהודה מגנטית גרעינית | In Hebrew = ЯМР | Я́дерного магни́тного резона́нса | In Russian = НМР | Нуклеарна магнетна резонанција | In Serbian |
In English | → Medicine → Nuclear, atomic, and molecular physics → 629031 |
| NMTBA | National Machine Tool BUilders' Association | In English | → Associations → Mechanical engineering |
| NMTS | Next Manned Transportation System | In English | → Vehicle engineering |
| NNPT | Nuclear Non-Proliferation Treaty | In English | → International relations → Nuclear technology → Military engineering |
| NNSA | National Nuclear Security Administration | In English | → Central administration → Nuclear technology |
| NOES | National Operational Environmental Satellite | In English | → Environment, environmental sciences → Spaceflight engineering, astronautics |
| NOL | Niezidentyfikowany Obiekt Latający = NIFO, OVNI, НЛО, UFO, עב"מ, NLO, OZN (look above) |
In Polish | → Spaceflight engineering, astronautics |
| NOMIS | Nuclear Operations and Maintenance Information Service | In English | → Maintenance and logistics → Nuclear technology |
| NORAD | North American Air Defense Command | In English | → 358 → Military engineering → Aeronautics, aircraft |
| NORAD | North American Aerospace Defense Command | In English | → 358 → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| NOSS | National Oceanic Satellite System | In English | → Marine research, oceanography → Spaceflight engineering, astronautics |
| NPC | NASA Publication Control | In English | → Spaceflight engineering, astronautics |
| NPC | NASA Procurement Circular | In English | → Spaceflight engineering, astronautics |
| NPD | NASA Policy Directive | In English | → Management → Spaceflight engineering, astronautics |
| NPL | Normal Power Level | In English | → Electrical engineering |
| NPN | NASA Part Number | In English | → Spaceflight engineering, astronautics |
| NPS | Nonpropulsive Stage | In English | → Spaceflight engineering, astronautics |
| NPS | NASA Planning Studies | In English | → Spaceflight engineering, astronautics |
| NPS | Nuclear Power Station | In English | → Nuclear technology |
| NPSS | NASA Packet Switching System | In English | → Spaceflight engineering, astronautics |
| NPT | Navy Pointer and Tracker | In English | → 359 → Military engineering |
| NRA&A | Nouvelle Revue d'Aéronautique et d'Astronautique | In French | → Serial publications, periodicals → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| NRALT | NASA Radar Altimeter | In English | → Geodesy, cartography → Spaceflight engineering, astronautics |
| NRB | Nuclear Reactor/Brayton | In English | → Nuclear technology |
| NRC | Nuclear Regulatory Commission | In English | → Nuclear technology |
| NRDS | Nuclear Rocket Development Station | In English | → Nuclear technology → Spaceflight engineering, astronautics |
| NREL | National Renewable Energy Laboratory | In English | → Research institutes → Energy economics |
| NRRv | Naval Research Reviews | In English | → Serial publications, periodicals → 6295 → Transport and postal services |
| NS | Nuclear Shuttle | In English | → Nuclear technology → Spaceflight engineering, astronautics |
| NSC | NASA Standard Computer | In English | → Hardware → Spaceflight engineering, astronautics |
| NSCCA | Nuclear Safety Cross-Check Analysis | In English | → Nuclear technology |
| NSD | NASA Standard Detonator | In English | → Spaceflight engineering, astronautics |
| NSE | Nuclear Science Engineering | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NSI | NASA Standard Initiator | In English | → Spaceflight engineering, astronautics |
| NSI | NASA Science Internet | In English | → Internet → Spaceflight engineering, astronautics → Astronomy |
| NSIA | National Security Industrial Association | In English | → Associations → Military engineering |
| NSIF | Near-Space Instrumentation Facility | In English | → Astronomy → Spaceflight engineering, astronautics |
| NSLD | NASA Shuttle Logistics Depot | In English | → Maintenance and logistics → Spaceflight engineering, astronautics |
| NSO | NASA Support Operation | In English | → Spaceflight engineering, astronautics |
| NSP | NASA Support Plan | In English | → Spaceflight engineering, astronautics |
| NSTI | NASA Simulation Traffic Interface | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| NSTL | National Space Technology Laboratories | In English | → Research institutes → Astronomy → Spaceflight engineering, astronautics |
| NSTS | National Space Transportation System | In English | → Spaceflight engineering, astronautics |
| NTA | National Technology Alliance | In English | → Organizations and associations |
| NTCo | Nondestructive Testing Communications | In English | → Serial publications, periodicals → Materials science |
| NTD | NASA Test Director | In English | → Spaceflight engineering, astronautics |
| NTE | Navigation Telemetry Encoder | In English | → Geodesy, cartography → Vehicle engineering |
| NTIS | National Technical Information Service | In English | |
| NTN | New Technology News | In English | → Serial publications, periodicals |
| NTPC | Nam Theun 2 Power Company (www.namtheun2.com) | In English | → Electrical engineering |
| NTRAC | New Technical Regulations Applications Committee | In English | → Standardization |
| NTS | Navigation Technology Satellite | In English | → Spaceflight engineering, astronautics |
| NTSC | Nuclear Technology Safety Center | In English | → Nuclear technology |
| NTSO | NASA Test Support Office | In English | → Spaceflight engineering, astronautics |
| NTUA | National Technical University of Athens | In English | → Higher education, universities |
| NU | Northeast Utilities | In English | → Energy economics |
| NUAAJ | Nanjing University Aeronautics and Astronautics Journal | In English | → Serial publications, periodicals → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| NucFS | Nuclear Fusion Special Supplement | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucFu | Nuclear Fusion | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucIM | Nuclear Instruments and Methods | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucTe | Nuclear Technology | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucTF | Nuclear Technology Fusion | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NUDET | Nuclear Detonation | In English | → Nuclear technology → Military engineering |
| NUDTJ | National University Defense Technology Journal | In English | → Serial publications, periodicals → Military engineering |
| NuEnD | Nuclear Engineering and Design | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NUFEM | Nagoya University Faculty Engineering Memoirs | In English | → Serial publications, periodicals |
| NUSEM | Nagoya University School Engineering Memoirs | In English | → Serial publications, periodicals |
| NUSS | NUclear Safety Standards | In English | → Nuclear technology |
| NV | NASA Altimeter Verification | In English | → Spaceflight engineering, astronautics |
| NV | Nuclear Vehicle | In English | → Nuclear technology → Vehicle engineering |
| NVAFB | North Vandenberg Air Force Base | In English | → 358 → Aeronautics, aircraft |
| NVR | NASA Waiver | In English | → Spaceflight engineering, astronautics |
| NWE | Nuclear Weapons Effect | In English | → Nuclear technology → Military engineering |
| NWMP | Nuclear Weapons Monitor Plan | In English | → Nuclear technology → Military engineering |
| NWP | Netherlands Water Partnership | In English | → Organizations and associations → Hydrology → Environmental technology, water supply, waste management |
| NWS | Neckarwerke Stuttgart AG | In German | → Energy economics |
| O&O | Onderzoek en Ontwikkeling = R&D | Recherche et développement | In French = F&E | Forschung und Entwicklung | In German = R&D | Research and Development | In English = I+D | Investigación y Desarrollo | In Spanish = R&S | Ricerca e Sviluppo | In Italian = P&D | Pesquisa e Desenvolvimento | In Portuguese = FoU | Forsøk og Utvikling | In Norwegian |
In Dutch | → Research policy |
| OAA | Orbiter Access Arm | In English | → Spaceflight engineering, astronautics |
| OAA | Orbiter Alternate Airfield | In English | → Spaceflight engineering, astronautics |
| OAC | Orbital Activation and Checkout | In English | → Spaceflight engineering, astronautics |
| OAFD | Orbiter Aft Flight Deck | In English | → Spaceflight engineering, astronautics |
| OAFTO | Orbiter Atmospheric Flight Test Office | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OAHTS | Orbiter Avionics Hardware Tracking System | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OALC | Ogden Air Logistics Center | In English | → Maintenance and logistics → Aeronautics, aircraft |
| OAME | Orbital Attitude and Maneuvering Electronics | In English | → Electronics → Spaceflight engineering, astronautics |
| OAMP | Optical Airborne Measurements Program | In English | → Aeronautics, aircraft |
| OAMS | Orbital Attitude and Maneuvering System | In English | → Spaceflight engineering, astronautics |
| ÖAMTC | Österreichischer Automobil-, Motorrad- und Touring Club | In German | → Organizations and associations → Vehicle engineering → Transport and postal services |
| OAO | Orbital Astronomical Observatory | In English | → Observatories → Spaceflight engineering, astronautics |
| OARE | Orbital Acceleration Research Experiment | In English | → Astronomy → Spaceflight engineering, astronautics |
| OARME | Oxygen Atom Reaction Materials Experiment | In English | → Nuclear, atomic, and molecular physics → Nuclear technology |
| OARS | Orbiter Avionics Radiation Specification | In English | → Aeronautics, aircraft |
| OAS | Orbiter Atmospheric Simulator | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OAS | Orbiter Avionics System | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OAS | Orbiter Avionics Simulator | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OAS | Orbiter Aeroflight Simulator | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OAS | Office Automation System | In English | → Mechanical engineering |
| OASCB | Orbiter Avionics Software Control Board | In English | → Software → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OASIS | Orbit Avionics Software Integration Study | In English | → Software → Aeronautics, aircraft |
| OASM | Office of Aerospace Medicine | In English | → Medicine → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OAST | Office of Aeronautics and Space Technology | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OATS | Orbiter Avionics Tracking System | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OCA | Orbiter Capability Analysis | In English | → Spaceflight engineering, astronautics |
| OCA | Orbiter Capability Assessment | In English | → Spaceflight engineering, astronautics |
| OCA | Ouest Convoyeur et Automatisme | In French | → Mechanical engineering |
| OCAC | Orbiter Cabin Air Cleaner | In English | → Spaceflight engineering, astronautics |
| OCALC | OKlahoma City Air Logistics Center | In English | → Maintenance and logistics → Aeronautics, aircraft |
| OCAM | Optimal Control Applications and Methods | In English | → Serial publications, periodicals |
| OCCP | Orbit Command Computer Program | In English | → Software → Spaceflight engineering, astronautics |
| OCDR | Orbiter Critical Design Review | In English | → Spaceflight engineering, astronautics |
| OcEng | Ocean Engineering | In English | → Serial publications, periodicals → Marine research, oceanography → 6295 |
| OCF | Orbiter Computational Facilities | In English | → Computer science → Spaceflight engineering, astronautics |
| OCH | Orbiter Common Hardware | In English | → Hardware → Spaceflight engineering, astronautics |
| OCP | Office Chérifien des Phosphates = م ش ف | مجموعة المكتب الشريف للفوسفاط | In Arabic |
In French | → Mining → Chemical technology |
| OcPhE | Ocean Physics and Engineering | In English | → Serial publications, periodicals → Marine research, oceanography → 6295 |
| OCRTAEMS | Office Central pour la Répression du Trafic des Armes, des munitions, des produits Explosifs et des Matières Sensibles | In French | → Police → Military engineering |
| OCTW | Optical Communications Through the shuttle Window | In English | → Spaceflight engineering, astronautics |
| ODE | Observatoire Départemental de l'Eau | In French | → Regional administration → Hydrology → Environmental technology, water supply, waste management |
| ODF | Orbit Determination Facility | In English | → Astronomy → Spaceflight engineering, astronautics |
| ODIN | Orbital Design Integration System | In English | → Spaceflight engineering, astronautics |
| ODM | Orbiter Disconnect Mechanism | In English | → Spaceflight engineering, astronautics |
| ODRC | Orbiter Data Reduction Center | In English | → Data → Spaceflight engineering, astronautics |
| OEAS | Orbital Emergency Arresting System | In English | → Spaceflight engineering, astronautics |
| OECO | Outboard Engine Cutoff | In English | → Vehicle engineering |
| OECS | Orbital Express Capture System | In English | → Spaceflight engineering, astronautics |
| OEM | Original Equipment Manufacturer | In English | |
| OEPS | Operationally Efficient Propulsion System | In English | → Vehicle engineering |
| OES | Orbiter Emergency Site | In English | → Spaceflight engineering, astronautics |
| OET | Orbiter Engineering and Test | In English | → Spaceflight engineering, astronautics |
| OEW | Oberschwäbische Elektrizitätswerke | In German | → Electrical engineering |
| OEX | Orbiter Experiment | In English | → Spaceflight engineering, astronautics |
| OF | Orbital Flight | In English | → Spaceflight engineering, astronautics |
| OFDS | Orbiter Flight Dynamic Simulator | In English | → Computer simulation → Spaceflight engineering, astronautics |
| OFI | Operational Flight Instrumentation | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OFK | Optical Flight Kit | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OFP | Operational Flight Profile | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OFP | Operational Flight Program | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OFP | Orbiter Flight Program | In English | → Spaceflight engineering, astronautics |
| OFS | Orbital/Orbital Flight System | In English | → Spaceflight engineering, astronautics |
| OFS | Orbiter Flight Simulator | In English | → Spaceflight engineering, astronautics |
| OFS | Orbiter Functional Simulator | In English | → Spaceflight engineering, astronautics |
| OFT | Orbital Flight Test | In English | → Spaceflight engineering, astronautics |
| OFT | Operational Flight Test | In English | → Aeronautics, aircraft → Spaceflight engineering, astronautics |
| OFT | Orbital Flight Training | In English | → Spaceflight engineering, astronautics |
| OFTDS | Orbital Flight Test Data System | In English | → Data → Spaceflight engineering, astronautics |
| OGK | Optovaya Giéniérirouyouchtchaya Kompaniya = ОГК | Оптовая генерирующая компания | In Russian |
In Russian | → Energy economics → Electrical engineering |
| OGMT | Orbiter Greenwich Mean Time | In English | → Spaceflight engineering, astronautics |
| OHA | Orbital Height Adjustment Maneuver | In English | → Spaceflight engineering, astronautics |
| OHGVT | Orbital Horizontal Ground Vibration Test | In English | → Spaceflight engineering, astronautics |
| OI | Orbiter Insertion | In English | → Spaceflight engineering, astronautics |
| OI | Orbiter Instrumentation | In English | → Spaceflight engineering, astronautics |
| OIA | Orbiter Interface Adapter | In English | → Human-computer interaction → Spaceflight engineering, astronautics |
| OIAC | Organisation pour l'Interdiction des Armes Chimiques (www.opcw.org) = OPWC | Organisation for the Prohibition of Chemical Weapons | In English |
In French | → Organizations and associations → International relations → Military engineering |
| OIC | Orbital Integrated Checkout | In English | → Spaceflight engineering, astronautics |
| OIE | Orbiter Integration Engineering | In English | → Spaceflight engineering, astronautics |
| OIE | Oficina per a la Innovació Empresarial | In Catalan | |
| OIEA | Organismo Internacional de Energía Atómica (www.iaea.org) = IAAE | Internacia Agentejo pri Atom-Energio | In Esperanto = IAEA | International Atomic Energy Agency | In English = AIEA | Agence Internationale de l'Énergie Atomique | In French = AIEA | Agenţia Internaţională pentru Energie Atomică | In Romanian = МААЕ | Международна агенция за атомна енергия | In Bulgarian = AIEA | Agència Internacional de l'Energia Atòmica | In Catalan = MAAE | Mezinárodní agentura pro atomovou energii | In Czech = IAEA | Det Internationale Atomenergiagentur | In Danish = IAEO | Internationale Atomenergieorganisation | In German = סבא"א | הסוכנות הבינלאומית לאנרגיה אטומית | In Hebrew = IAEA | International Atomenergie Agence | In Letzeburgesh = AIEA | Agenzia Internazionale per l'Energia Atomica | In Italian = IAEA | अंतर्राष्ट्रीय परमाणु ऊर्जा अधिकरण | In Hindi = MAAE | Меѓународна агенција за атомска енергија | In Macedonian = МАГАТЭ | Международное агентство по атомной энергии | In Russian = AIEA | Agência Internacional de Energia Atómica | In Portuguese = MAEA | Międzynarodowa Agencja Energii Atomowej | In Polish = МАГАТЕ | Міжнародне агентство з атомної енергії | In Ukrainian = UAEA | Uluslararası Atom Enerji Ajansı | In Turkish = IAEA | สำนักงานพลังงานปรมาณูระหว่างประเทศ | In Thai = EANA | Energia Atomikoaren Nazioarteko Agentzia | In Basque |
In Spanish | → International relations → Energy economics → Nuclear technology |
|