it isn't something to memorize. In order to obtain the code, head to the Valhala, which personally creeps me out every time i go there. you will need quite a few energy cells, i don't remember how many, but one thing i didn't notice until much later in the game is that there is an energy cell right in front of the doors to the space ship. when you're in the room of the metroid hatchlings, or baby metroids, or whatever they're called, head to the left, and not the right. there is just a missle expansion to the right. keep moving forward until you reach a room where you can see out the window thousands of phazon metroids, and some come in and attack you. move straight and not left, i think, and there is a ghost of a galactic federation trooper that doesn't say anything, an it does not draw attention to it. keep goinf until you ecounter another metroid hatacher, which requires two more energy cells. after defeating it, you will gain access to a room where a few more metroids are, and then a dead end where a bunch of deceased GF troopers and space pirates are, and in the ship of the space pirate, using the x-ray scope, i think, you will download the code for the leviathan. head back to the leviathan, and prepare to take on Dark Samus!