At the end of a mission, everyone on the space team gets an award. What possible awards are there, and what decides which one is given to which person?
Well, I don't want to ruin the mystery completely but I can give you an idea. Unlike the Team Accomplishment stats, which are shared by the whole team, the medal you're awarded is often a reflection of your individual performance.
The game tracks a bunch of statistics and tries to pick the single thing that you did particularly well, or particularly poorly.
For example, if you gave/spoke the most successful instructions then you might be awarded for your "eloquence" or "commanding voice". Alternatively, if you made the most unnecessary control changes you might get a medal for your "enthusiasm". But enthusiasm is also awarded for most-successful-shakes-to-avoid-asteroids, so you can never be entirely sure... ;)
And finally, there are some unique medals that were contributed by Spaceteam Admiral's Club Commanders. They get awarded when there's no particular stat that you were best or worst at.