This is a repeatable quest that will be triggered by completing the Brotherhood of Steel's Semper Invicta quest. Talk to Scribe Haylen in the Cambridge Police Station and she'll mark /specify a location in your map where you can retrieve a piece of tech. Head to the location, fight your way through any hostiles and retrieve the artifact. Deliver it to Scribe Haylen to complete the quest.
The possible locations where she'll ask you to find the techs are: