Find a way to bring the Data Processing Tower back on-line.

First off, exit the room you're in and call the elevator in the center. Ride it up inside the tower. Feel free to shoot down that repair bot for some target practice. You'll see doors on either side; head through the unlocked one.

Interact with the 'Activate Bridge' panel to extend a bridge. Cross it to the other side. To your left, you'll find a crate with two LARGE HEALTH PACKS. On the opposite side, there are NAILS and ROCKETS. Grab them, then head through the door.

In the next room, you'll need to take out a Gunner. After that, you'll notice two teleporters on each side of the room. It's a good idea to shoot them up and destroy them to prevent any unwanted guests from showing up. There's also a crate here with two LARGE HEALTH PACKS and a SMALL ARMOR VEST.

Now for a room that can be a bit of a pain. In the back, there are two teleporters that can spawn up to three Tactical Transfers each. You'll also have a Gladiator to deal with. Your best bet is to destroy those teleporters as quickly as possible to minimize the number of enemies you face, but honestly, there's plenty of cover around if you need it. Once the room is clear, move through the next door.

Walk forward and wait for the bridge to extend. Once it's safe, cross over to the control panel and click 'Activate Power'. This will complete your first objective in the tower.

Before heading back, check the back of this platform for another LARGE HEALTH PACK and a SMALL ARMOR VEST.

Now, head back into that previous room. It's about to get even more intense. You'll first be attacked by an Iron Maiden – try to dodge her. Then, a Teleport Dropper and a second Iron Maiden will appear. Focus on killing the Dropper quickly while avoiding the Maiden. After that, a Light Tank will roll in, so keep moving and blast it with your favorite weapon.

Once that room is clear again, backtrack to the room before it. If you didn't destroy those teleporters earlier, they might spawn up to two Tactical Marines each, so be ready.

Finally, return to the central tower area to meet up with Sledge. Call down the elevator in the room ahead; this will allow you and Sledge to proceed.