@FalloutJackTo better illustrate, Someone who takes note of everyone's progress and updates, forwards relevant information based on findings, while stating observation, analytics, and general status updates.
Basically. "I'm nearby, but I might not really be in a fight, the safety of the ship, or orbit is fine."
To better simplify, I guess sorta like... Think of the characters from Metal Gear Solid who do not appear to help you on foot, but keep you updated from the sidelines. (Could also say someone like Arthur from Shin Megami Tensei: Strange Journey.)
Collects general information based on your findings, makes a chart based on it.
Notes resources in the areas based in findings for a reference point.
In a safe place, he might take note of your physical health, and personally inquire how you are feeling. (Mostly because if there is something going on, he'd want a scan on it.)
Tl;dr - General Analytics, not a combatant role, but works as a pillar of support in his own way. Keeps track of progress. For the most part, neutral on opinions, and cares for the facts. Keeps everyone updated. (Mostly because the isolation of Metroid styled Worlds, I imagine they split up when dealing with separate objectives, or just generally split up due to complications.) Probably has the least combat experience, but by no means useless.
However, if this is not to your interest, I can work around it.