| Abbreviation | Definition |
|---|---|
| NPG | NASA Procedures and Guidelines |
| NPL | Normal Power Level |
| NPLD | NASA Payloads Logistics Depot |
| NPN | NASA Part Number |
| NPO | Next Planet Over |
| NPP | National Polar-orbiting Partnership |
| NPP | NPOESS Preparatory Project |
| NPR | NASA Procedural Requirements |
| NPRP | NASA Postdoctoral Research Program |
| NPRV | Nitrogen Pressure Relief Valve |
| NPS | NASA Planning Studies |
| NPSH | Net Positive Suction Head |
| NPSP | Net Positive Static Pressure |
| NPSP | Net Positive Suction Pressure |
| NPU | Nitrogen Purge Unit |
| NPV | Nitrogen Pressure |
| NPV | Nitrogen Pressure Vessel |
| NPW | NASA ParaWing |
| NR | Noise Rating |
| NR | Nose Right |