You need to gather the necessary materials to craft a chestpiece for your armor at a research station.
Talk to Jacob Mittney in Prodromos on Eos. You need to finish A Better Beginning mission first, and then come back to Eos.
Task: Pathfinder Armor Crafting
Related points of interest
Mission objectives of Task: Pathfinder Armor Crafting
1. Craft the Pathfinder chestpiece
Use the research center to craft it.
