Ship to Ship combat - Low pop event role, crew have to deal with ship to ship combat with an enemy vessel and have to deal with a series of critical issues, such as powercuts, boarders, parts of the ship being breached (don't need atmos for this, just sleep anyone who enters without relevant protection and kill em if they don't get saved in time)
Military Tribunal - Monitor the actions of marine(s) who has commit major/capital crimes prior round, host a court martial based on said player(s) actions with the Provost present and shipside crew there.
Pacify the Colony - Marines are deployed to a large colony, fully functioning. A handful of individuals are CLF insurgents, the rest are colonists. Give the CLF insurgents objectives and if they complete them, they get assistance/bonuses.