Dead Space 3 walkthrough, Part Eleven: Back to the Roanoke
In a stunning act of heroism - or suicidal mania, they're kinda the same thing for this guy - Isaac has not only prepped a shuttle for launch from the Terra Nova, he's stopped a countdown that would have sent it unto the breach without a crew. Now he's floating in space, enjoying the accolades of his peers… and needs to get back into Terra Nova.
After all you've just gone through, this seems like it should be a cakewalk. Spacewalk. Whatever. Surprisingly, though, the trip back to the Terra Nova's innards is rather hazardous. There are Necromorph blobs that will spew projectiles at you, and, even more deadly, there are tracking mines that will tag you all the way to the personnel bay you need to reach. Jet ahead of these mines and blow them up from a distance. You may not see them at first, but they are definitely following you around.
The personnel bay is up the red shaft at the far end of this stretch of space, and it's your first priority. After you've reached it, though - and after you've received a new mission - you might as well head back out and have a look around. There's only one thing to find out here, but it's worth the look: an S.C.A.F. Artifact. It's hiding behind the biggest piece of wreckage floating in this section, and you can easily grab it on a return trip without getting hit by any Necromorph blob attacks. Keep an eye open for a tiny glint of white on the wrecked hull.
That grabbed, return to the docking bay of the Skip and hop in. You now need to find an engine part for the Crozier over at the Greely, the site of an optional quest you could have done before entering the Terra Nova. Now's not a bad time to get it done; if you're not interested, well, you're still heading there anyway.
Leave the Skip and zip out towards the bow of the Greely. One of your crew is waiting (such a friendly guy) along with some projectile-flinging Necromorphs on the giant hunk of green hull just below the Greely. Take them out by hurling debris at them with Kinesis and inspect the engines. You need to remove the three panels on the side of the engine casing, the blocks under those, and the engine itself after that. Watch out, as more Necromorphs will appear from the ship nearby and try to lob potshots at you.
Done? No, not yet. The shuttle needs a flight plan. Isaac can find three of the solar-panelled satellites which can provide said flight plan outside the Roanoke. Return to the Skip and zip over to the Roanoke. The satellites aren't too hard to find; head towards the central hub of the Roanoke (the large tower in the middle) and you'll find all three near a small minefield. Take out any mines that latch onto you, and mind the Necromorphs lobbing projectiles from the tower.
The last thing you need is a Bench. Enter the Roanoke and you'll find one back where you last left Ellie. The Bench will assemble a nice little Nav Array, and after some bickering with Captain Norton you can float back outside to install the thing. Plug it into the nose of the shuttle, then land on the side of the craft and open the door. Welcome home! Off to Tau Volantis with your suicidal butt!