Clockwise from top left:
The Bronze Star: Awarded for exceptional bravery under fire.
The Gold Star: Awarded for exceptional bravery against hopeless odds.
The Silver Star: Awarded for exceptional bravery against overwhelming opposition. When a recipient wins an additional Silver Star, an extra bar is affixed to the top of the ribbon area.
The Terran Confederation Medal of Honor: Also nicknamed the "Pewter Planet," this is the highest medal awarded to military personnal.
The Golden Sun: Awarded for surviving the destruction of one's ship. The Golden Sun is awarded only once. The subsequent loss of ships get you only the requisite, especially intensive, debriefing sessions and performance evaluations.