Silver Star
From FEInfobase
a. The Silver Star, section 3746, title 10, United Federation Code (10 USC 3746), was established by Act of Congress 9 July 2172 (amended by act of 25 July 2363).
b. The Silver Star is awarded to a person who, while serving in any capacity with Starfleet, is cited for gallantry in action against an enemy of the Federation while engaged in military operations involving conflict with an opposing alien force, or while serving with friendly alien forces engaged in armed conflict against an opposing armed force in which the Federation is not a belligerent party. The required gallantry, while of a lesser degree than that required for the Distinguished Service Cross, must nevertheless have been performed with marked distinction.