He would not just kill himself. He would take a bullet or the brunt of an explosion if it was the only way to save his team. (like when he gave to oxygen mask to Private when they were both in space)

No, they need him to survive.

@mouseandowl: I have more faith in the team than that. Skipper may be the natural born leader and the team does get a bit hectic without him, but I think if it came down to it, they could learn to be without him, especially in his honor if he made such a sacrifice,one which I think Skipper is ready and willing to make if necessary.

He'd defiantly make that sacrifice - he's dedicated to them. but the team probably wouldn't let it happen.