Traditionally, the Second Officer is an officer who is third in command of a starship and who assumes command of the ship when both the Captain and First Officer are unavailable.

Within STARFLEET International, and aboard the USS Alan Turing, the Second Officer is the head of the three divisions representing the liaison between the Command Crew and the Divisions and their departments.  In the event that both the CO and XO become unavailable, the command of the chapter is given to them temporarily while they work with the Regional Command, giving them the opportunity to become the CO if they choose or just holding the position until a new CO and XO are chosen.

Aboard the USS Alan Turing, the Second Officer is Lieutenant Commander Kiani Glenn, known by her persona as a Vulcan officer, Lieutenant Commander Hassel, SFMD.  Driven by a desire to understand more deeply the hearts and minds of other species in hopes to better understand their own, Hassel joined Starfleet Academy and graduated from it and Starfleet medical. A long standing member, Hassel was originally brought on to the ship as Chief Medical Officer, but has since stepped up to second officer.