He 'kept/maintained his cool' [=he didn't get angry or upset] even though it was clear that he was being unfairly treated.
He was struggling to 'maintain his cool/composure'. [=he was struggling not to become angry or upset]
They barely had enough food to 'maintain life'. [=to make it possible for life to exist or continue]
(..) Minutes, sir. Minutes. Alert Vulcan command center to signal a planet wide evacuation... all channels, all frequencies. - Spock, wait. - Maintain standard orbit. - Yes, sir. - Where are you going? To evacuate the Vulcan High Council. Their task is to protect (..)2009 Star Trek
(..) define the purpose of the test. - Enlighten me again. - The purpose to experience fear. Fear in the face of certain death. To accept that fear and maintain control of oneself and one's crew. This is a quality expected in every Starfleet captain. Excuse me, sir. We've received a distress (..)2009 Star Trek