Mountain Standard Time 
Maintenance Support Tool 
Mobile Service Tower 
Mission Sequence Test 
Maintenance Support Team 
Manifold Surface Temperature 
Modular Servicing Tool 
MASTERFILT 
Measurement Science and Technology 
Mesosphere Stratosphere Troposphere 
mission support team 
Module Service Tool 
Monolithic Systems Technology 
Maintenance Support Terminal 
Marketable Securities Tax 
Mars Study Team 
Master of Studies 
Materials Science and Technology 
Mathematics Science And Technology 
Maximal Stimulation Test 
Mean Solar Time 
mean survival time 
Measurement Status Table 
medium-scale technology 
Meteorological Support Teams 
Micro System Technology 
microbial source tracking 
Miniature Satellite Transceiver 
minimum spanning tree 
Mobile Support Team