No sure if you've got this fixed yet but I had the same issue with the servitor not spawning. Our problem was that if you go to quickly and clear the adds and get the scanner buff before going up to the station you will be stuck on the same step of the mission of getting to the station. What you have to do if this is the issue you're having, which worked for me, is slow down when you get to the fallen outside the pods, let the objective update, kill them then let the objective update and proceed as normal. Hope this helps

I've now had that same bug with the turret room and the security officer room not spawning shriekers for me to advance. It's the 6th time trying. I've tried going slow (Took 20 minutes to chill outside the area for a bit), I've tried killing all champions leading up to that room including the ogre at the start, I've tried to kill turrets before entering the room and then leaving the champion security officer for last, and still nothing works. I keep getting the same thing: Augment unavailable. I can't deposit my augment to advance past the engineering room. Bungie I'm officially quitting the game until this bug has been patched. Bungie this type of QA review you guys are employing to push out quality content is not up to par to today's standards and needs some serious review otherwise, better and more hardworking developers will be either replacing you or making you their competition which right now doesn't sound too far off base.

Make sure you interact with the dead exo for that week. If you are doing it all at once then find all the dead exos for part 1, part 2, and part 3.

I have completed it 3 times and the quest will not complete all on legendary so frustrating!