Environmental Control System 
Engagement Control Station 
Electronic Certification System 
Electronic Crash Sensor 
Emission Control System 
European Communications Satellite 
Expeditionary Combat Support 
Elitegroup Computer Systems 
Emergency Communications Staff 
Education Commission of the States 
Electronic Chart Systems 
European Communications Satellites 
Embedded Computer System 
Embedded Computer Systems 
Energy Conversion Subsystem 
Engine Control System 
Enterprise Communications Server 
Environment Control System 
Environmental Conditioning System 
Environmental Control Subsystem 
Environmental Control Systems 
EOSDIS Core System 
Equipment Concentration Site 
Executive Correspondence Staff 
Experimental Communications Satellite 
EXTENDED CORE STORAGE 
External Complaint Staff 
East China Sea 
Ecuadorian Sucre 
Education Career Stabilization