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.
Best Answer
There are really two problems here: the player/character isn't suitable for some scenes, and some scenes aren't well-suited to one of your PC's. You need to meet in the middle. (I think all sci-fi RPGs, and stories generally, have to deal with this problem to an extent; I'll be basing my answer on experience GMing a homebrew GURPS Star Wars game and playing in D20 Star Wars.)
The PC
First, ask your player - does he categorically not enjoy non-social roleplaying situations himself, in general, or is the frustration only coming from the fact that his particular character is a bit useless? If it's the former, your job is a lot harder, and it's all on you (see below). If it's the character, however, you've got some options.
The Story
If the player really doesn't enjoy non-social scenes, at the end of the day it's most likely that you'll all have to accept either a certain amount of rotating between activities you tolerate and ones you enjoy, or not playing together. But there are still some mitigations you can apply.