I've done this it gives you an emblem you then kill an ultra knight [spoiler]emblem after ultra knight[/spoiler]

When you scan the terminal that only opens when you kill Psion Operatives, it activates the Deployment Codes panel up in the Mausoleum. Scanning both I have not done yet.

If you're referring to the two consoles that you can activate by scanning them with your Ghost, my buddy and I tried this out. There are the two consoles in rooms on opposite sides of the area. We activated both of them at the same time (I scanned one and he scanned another). When we did this the door in the middle of the area (it's up a ramp, between two control booths, and can't be opened with a Ghost) will open up. We went through the door and entered an area called "the bridge". We fought some enemies and eventually exited the ship and entered a chamber where we fought some Hive majors. There are some other doors in this section that we couldn't open up. I assume they can be opened in a mission or with some trick we didn't know about. I think we did find a Calcified_Fragment in the chamber with the Hive majors. Sorry if I'm not clear on every detail. It was late at night and it was the last thing we did before I went to sleep.

Where exactly was it?