“Search the Dreadnaught to locate and disable the power source for the weapon that destroyed Eris's ship.”
Keep on guard because you will quickly encounter Thralls coming out in that direction. Deal with them then head to the left. You can look in the ground just inside that room to find a strange worm you can scan. Apparently the Hive eat these, moths and other things. You will see more of those worms and some Thralls.
Take out the Thralls and head deeper into the room. To get out of this room, head for the crack in the wall just to the right of where you came in. Go through it and turn to the left. Head down the corridor in front of you. Continue forward until you find the next break in the wall. Head on through it and then go right. Just keep following it until you find another breach in the wall. This one leads out to a massive chasm.
Pull out Ghost and use him to see the next of platforms. The good news is as you step on them, they will materialize and be plainly visible. Once on the other side, head over to the left.
Head into the room there and you will be able to see the first power conduit. Approach it.