I have a player (I'll call him Jeff) whose PC is a peaceful diplomat. He invested most of his points in Charisma and charisma-based skills. He also has minor telepathy (able to read and influence emotions). He also has great Wisdom and is a fair shot with a pistol. The game is three players and myself as GM, so making sure his PC is useful counts for 33% of the players feeling like they're participating.
They're both enjoying the game a lot! They both feel like they fit into their roles very well. So this one flaw of Jeff feeling useless a lot of the time is something that would make the game that much better.
Roughly a third to a quarter of adventures do or will take place in space. Jeff hasn't felt like his PC has been useful in non-social situations, particularly starship combat. He likes talking with the captains of other ships and stuff, but not so much starship combat, navigation, and space adventures in general.
He doesn't feel useful in ground-based combat situations unless there's a social angle he can work. (He once tried to avoid being shot by a bandit leader by literally offering to kill the others — once he stopped bleeding. This may or may not have been a ruse.)
How do I get him to feel useful in non-social situations, particularly during starship sequences? I feel like I could meld social encounters with other types, but I'm not sure how to go about that.