*** Cora's loyalty mission ***
*** Spoiler - click to reveal ***When you arrive in Voeld, an ice planet, you get a mission to investigate a signal from the Asari ark. After investigating some locations, you'll find a black box and have to wait for Cora to decode it.
Later in the game you'll receive an e-mail from Cora and her loyalty mission will start. Finish her mission and the achievement is yours.