Chorus

As you approach each new location or depending on where you are in the story - revisiting certain locations can trigger a side mission. Any incomplete side missions you have picked up will show under the main story missions on the mission tab, just complete 5 of them to unlock this very simple achievement. Many will reward the player with ship modules or upgrades as well as credits (very little use for credits - on completion of the game I had amassed far more than I could use).