I'm referring to the Call In Reinforcement mission, which if I'm not wrong is the follow-up to this mission.
Call in reinforcement at captured points. Earn command credits by defeating enemies or capturing points. Use command credits at captured points to call in reinforcements from your ship. Higher ranks will earn more credits towards mission completion:
Ensigns: 1 point (20 command credits)
Lieutenants: 5 points (40 command credits)
Commanders: 10 points (80 command credits)
Captains: 20 points (120 command credits)
And you need 20 points to complete this mission.