Message Transfer System 
Movement Tracking System 
Microsoft Transaction Server 
Mobile Telephone Service 
Message Transfer Service 
Moscow Time Standard 
Message Telecommunication Service 
Message Telecommunications Service 
Methods for Testing and Specification 
Modernization Through Spares 
Multichannel Television Sound 
Marine Tactical System 
Message Telephone Service 
Meteoroid Technology Satellite 
Microwave Temperature Sounder 
Mass Termination System 
MASTERS 
Member of Technical Staff 
member of the technical staff 
Message Telephone System 
Metropolitan Transportation System 
Michigan Terminal System 
Missile Test Station 
Mobile Transporter System 
Moored Training Ship 
Movement Tracking Systems 
Magnetic Tape Station 
Magnetic Tape Storage 
Magnetic Tape System 
Magnetic Torquing System