| Abbreviation | Definition |
|---|---|
| ERNO | Entwicklungts Ring NOrd (Northern Development Ring, Space Division of European Consortium) |
| ERO | Engineering Release Operations |
| ERP | Effective Radiated Power |
| ERP | Eye Reference Point |
| ERPM | Engineering Requirements and Procedures Manual |
| ERPS | Experimental Rocket Propulsion Society |
| ERR | ERRor |
| ERRC | Expendability/Recoverability/Repair Capability |
| ERRCNTR | ERRor CouNTeR |
| ERS | Earth Recovery Subsystem |
| ERS | Element Rotation Stand |
| ERS | Engineering Release System |
| ERS | Entry and Recovery Simulation |
| ERS-1 | Earth Remote Sensing Satellite-1 |
| ERSI | Elastomeric Reusable Surface Insulation |
| ERSIR | Earth Resources Shuttle Imaging Radar |
| ERT | Earth Received Time |
| ERTS | Earth Resources Technology Satellite |
| ERU | Earth Rate Unit |
| ERV | Expiratory Reserve Volume |