Launch is in the communications hub. Once you clear the first control point, head to the cafeteria, then through to dead letters. In dead letters, clear this control point. Next to the control point is a back entrance to Communications. Head through this door and down. You'll see a man get shot out of a doorway.
Go through the doorway, and sprint to cover. Sprint from cover to cover into the center right of the room. Jump up, then take the stairs here. On the upper portion, head left to the other side of the room and go towards the object firing at you. Hold
This will take you to the astral plane, where you will need to practice launching objects at walls and enemies. Once you've completed the practice, walk towards the glowing object and hold