they have only just been added. i know the tactical one is in the large room in the middle. there are two consoles either side of the central divide. activate them both to turn on the turrets.
have not seen the science or engineering ones but i think you have to keep your eyes open for them.
One is reading every prisoner Bio, it should unlock when you read the one in the cell next to the Founder (the Founder one is not required, if it does not unlock then you missed some).
Then there are class specific ones.
Science is on the Secondary ISIS Core.
Tactical is on the Section 2.
Engineering seems to also be in Section 2 (I dont have a Engineer character but when I did it with a group, it unlocked about the same time as the Tactical one).
I believe the panels on the Secondary ISIS Core will tell you were the Class specific options are with the, obvious, exception of the science option that is activated there.