Training Mission
Training Missions, or Gamma Missions, are small, return-on-same-day events. These missions are meant to train OCESS members, both new and old, how to conduct a space Mission, as well as offer new members a chance to experience a mission first hand.
Training missions also allow members to take on roles which they are not accustomed to. For example, a member who is usually an Astronaut might stay in Mission Control instead, or a member might be able to play the part of a Simulator for the first time.
Since training missions are, well, training missions, the atmosphere is much more loose and informal than on real missions, giving new members a chance to experience Sim Culture, as well as bond with other members in a fun environment.
Simulated Missions are considerd "Gamma", and are thus openly acknowlaged as simulations, unlike "Beta" missions which are considered real-life missions. In essense, they are simulations of a simulated mission.
Spacesim typically holds 2-3 training missions a year. One or two to train new members, and one at the end of the year to let off steam, such as a revenge mission or terrorist mission.