The Odysseus was part of a convoy along with Thor and Zeus. The convoy was to be attacked by Assault Gunboats and TIE Avengers, and the starships had to rely on X-wings from Rogue and Blue Squadrons to give the starships enough time to escape into hyperspace.
The outcome depends on which side the player takes.
Although the Mon Calamari Star Cruisers featured in Star Wars: X-Wing vs. TIE Fighter: Balance of Power Campaigns are identified in-game as MC80a Star Cruisers, that term was later retconned by the 2012 reference book The Essential Guide to Warfare to refer to a different model of cruiser depicted in Star Wars: Episode VI Return of the Jedi.