Mission specialist
A mission specialist was a position in Starfleet held by either Starfleet personnel or civilians during certain missions. 

In 2366, Tam Elbrun transferred to the  as a mission specialist for a first contact mission. ()

In 2368, Ensign Robin Lefler served as mission specialist on board the Enterprise for its survey of the Phoenix Cluster. ()

See also 
 Mission leader

External link

Occupations