| Abbreviation | Definition |
|---|---|
| NNI-I | NASA Standard Initiator-Type I (was SMSI) |
| NO | Nitric Oxide |
| NO | Normally Open |
| NO | Not for Off-KSC (Kennedy Space Center) Distribution |
| NO | Not for Off-KSC Distribution |
| No. | Number |
| NO2 | Nitrogen Dioxide |
| NOC | Network Operation Control |
| NOC | Not Otherwise Coded |
| NOC | Notation Of Content |
| NOCC | Network Operations Control Center |
| NOCR | Network Operations Control Room |
| NOES | National Operational Environmental Satellite Service |
| NOIS | NASA Open Innovation Service |
| NOM | Network Output Multiplexer |
| NOMN | News Of Mighty Ninth |
| NOMR | Nitrous Oxide Monopropellant Rocket |
| NOP | No Operation Point |
| NOPE | Network Operations Engineer |
| NOR | Normal |