Once you enter Engineering module, go right into the Mechanical Engineering wing.
You'll see "OPERATION MOONSHOT STATUS BOARD" in front of you. Go closer to it and look down - you gonna notice this ring but your character gonna say something like "I can't reach it right now...".
Going further with the story in this area you'll gonna need to open a door with a code, that given by another character. This opened door gonna lead you in alternative pass that goes bellow "status board" that noticed before.
Just take this ring and finish a game. You'll get an trophy after credits.