Mission Specialist
Mission specialist is a role added in 2009-10 to signify someone who has been trained for a specific duty outside of the basic Flight, Engineering, and EECOM programs. The duty of a mission specialist is that of any other astronaut - they help with basic systems, they go on EVA's and IVA's, and they do experiments, the only difference being that they have proficiency with another duty such as piloting a submarine or using a robot.
Mission Specialists in MC
Being a mission specialist in MC indicates that you have the skill to be a Flight Director, with the exception being that you are not a Senior Member. Mission specialists in MC aid the flight director with their duties such as running the MC software, giving orders, and their most important duty being that of assuming control if the fight director on duty has to leave MC for any reason such as to go to the washroom or to get food.
