Microgravity Science Glovebox 
Meteosat Second Generation 
message 
Master Sergeant 
Marine Security Guard 
Mechanical Subsystem Group 
Microgravity Sciences Glovebox 
Mission Support Group 
Maintenance Steering Group 
Materiel Systems Group 
Members' Services Group 
Military Support Group 
Modular steam generator 
Flavor enhancer 
machine stress-grade 
Madison Square Garden 
Maintenance and Service Guide 
maintenance support group 
Maintenance Support Guide 
Maintenance System Guide 
major surface glycoprotein 
malate synthase G 
Management Science Group 
Management Steering Group 
Manpower Scaling Guide 
Manufacturers Standard Gauge 
Mapper Sweep Generator 
Marine Systems Group 
Mars Global Surveyor 
Material Support Group