Hello everyone.
Here is a guide showing you the Locations of all 35 Dataslate Locations
There's a total of 23 in the campaign and 12 in Operation missions which unlock as you keep advancing through the story also the game has a missions select so if you miss one you can always go back and clean it up here's a link for the video with time stamps
Skyfire - Mission
0:01 Dataslate - 1
0:30 Dataslate - 2
0:48 Dataslate - 3
1:16 Dataslate - 4
Severance - Mission
1:52 Dataslate - 5
2:31 Dataslate - 6
2:58 Dataslate - 7
3:53 Dataslate - 8
Machinus Divinitus - Mission
4:06 Dataslate - 9
4:36 Dataslate - 10
5:22 Dataslate - 11
Servant of the Machine - Mission
5:43 Dataslate - 12
6:09 Dataslate - 13
Voidsong - Mission
6:34 Dataslate - 14
6:59 Dataslate - 15
7:28 Dataslate - 16
Dawn's Descent - Mission
7:48 Dataslate - 17
8:15 Dataslate - 18
8:43 Dataslate - 19
9:08 Dataslate - 20
Bellum Sempiternos - Mission
9:40 Dataslate - 21
10:09 Dataslate - 22
10:33 Dataslate - 23
Inferno - Operation
11:03 Dataslate - 24
11:35 Dataslate - 25
Decapitation - Operation
11:46 Dataslate - 26
12:19 Dataslate - 27
Vox Liberatus - Operation
12:30 Dataslate - 28
12:48 Dataslate - 29
Reliquary - Operation
12:59 Dataslate - 30
13:18 Dataslate - 31
Fall of Atreus - Operation
13:38 Dataslate - 32
14:21 Dataslate - 33
Ballistic Engine - Operation
14:54 Dataslate - 34
15:17 Dataslate - 35