| Acronym | Meaning |
| EPL | List |
| EPMS | Engineering Performance Management System |
| EPO | Element Project Office |
| EPOC | External Payload Operations Center |
| EPPS | Electrical Power/Pyro Sequential System |
| EPR | Engine Pressure Ratio |
| EPRN | Emergency Program Release Notice |
| EPROM | Erasable Programmable Read Only Memory |
| EPS | Electrical Power System |
| EPS | Electrical Power System (Subsystem) |
| EPS | ExPerimental Power Supply |
| EPSP | Experiment Power Switching Panel |
| EPT | Emergency Procedure Trainer |
| EPT | Ethylene Propylene Terpolymer |
| EPTU | Events Per Time Unit |
| EPWG | Environmental Projects Working Group |
| EQ | Equivalent |
| EQE | Event Queue Element |
| EQL | Equal |
| EQUIP | Equipment |
| EQUIV | Equivalent |
| ER | Explanation Report |
| ERA | Electrical Replaceable Assembly |
| ERAP | Earth Resources Aircraft Program |
| ERB | Engineering Review Board |
| ERBE | Earth Radiation Budget Experiment |
| ERBS | Earth Radiation Budget Satellite |
| ERC | Event Recorder |
| ERCA | Electrochemically Regenerable CO2Absorber |
| EREP | Earth Resources Package |
| ERG | Ergometer |
| ERNO | Of European Consortium |
| ERNO | Germany (SPacelab Contractor) |
| ERO | Engineering Release Operations |
| ERP | Effected Radiative Power |
| ERP | Effective Radiation Power |
| ERP | Eye Reference Point |
| ERPM | Engineering Requirements And Procedures Manual |
| ERR | Error |
| ERR | CNTR Error Counter |
| ERRC | Expendability/Recoverability/Repair Capability |
| ERS | Earth RecoverySubsystem |
| ERS | Engineering Release System |
| ERS | Entry And Recovery Simulation |
| ERSI | Elastomeric Reusable Surface Insulation |
| ERSIR | Earth Resources Shuttle Imaging Radar |
| ERTS | Earth Resources Technology Satellite |
| ERU | Earth Rate Unit |
| ERV | Expiratory Reserve Volume |
| ES | Escape System |