Second Officer

A function aboard a starship or a space station, a second officer assumed command when both the captain and first officer were unavailable. It was common for a second officer on a Star Fleet vessel or other installations to hold the rank of lieutenant commander. The second officer was a department head first, and a second officer second. He or she was rarely involved in the day to day command of the starship or starbase the way the captain or first officer was. It was standard procedure for the second officer to accompany away teams.