Grenade jump over the gaping hole
Did you know it's possible to grenade jump to the other side of the gaping hole that you encounter at the start of the level? I didn't think you could do it, but correspondent One One Seven reported eventual success, after which I tried again and was able to do it within a few minutes. Amazing how much easier something is once someone tells you it's possible! Just land a plasma grenade near the edge and take a running jump. Get the timing right (not easy) and crouch at the end to help, and you can just make it.
Not much fighting
There's not a lot of fighting to be had in the hangar on the other side, but it's a novelty at least. As for the stream of Flood that you leave behind, well actually they seem to stop coming after you, so I'm afraid you can't look forward to blasting loads of them from across the hole.
Checkpoint tips
Before you start making attempts at jumping over, wait for the checkpoint you become due when you approach the door. It might be delayed for a bit, either because of the fighting or because the game considers you under threat from the covies; but hopefully you'll get it before Flood start coming up behind you.
As soon as you realize that a jumping attempt is going to fail, which it probably will many times, revert to the checkpoint quickly else you'll get another checkpoint as you fall down into the coolant pool.