Every so often you have to let your players face inevitable destruction. A situation where the best they can hope to do is to leave a message behind for those who follow.

Of course it's the job of the players to get out of the inescapable situation. Don't make it easy for them, by all means, but do leave the door open just enough for them to see the crack of light.

Then slam it in their faces. Hard.

And then watch them get creative to try to find another way out. Only let them succeed if they think of something you didn't plan for. (Of course that's pretty much guaranteed to happen, but then you didn't really want to kill them all, did you?)

Transcript

R2-D2: All right, we can work with this. I still own half a ship.
Obi-Wan: I open a channel to the Jedi Council.
Anakin: What for?
Obi-Wan: To tell them everything we've discovered before we die.
Anakin: Screw that. I'm going to live.
Obi-Wan: We must be mindful of the highest probability outcome. People must be warned.
[SFX]: wwhhooHHRRHHH!!! {the ship starts breaking up as it re-enters the atmosphere}
GM: The radio's not working.
R2-D2: If only Jim were here.
Anakin: So he could die too?
R2-D2: Everything's already totally screwed. This is exactly the time when his ideas work best. Everyone, think like Jim!
{Anakin looks dumbfounded}
{Obi-Wan looks dumbfounded}
[SFX]: wwhhooHHRRHHH!!! {the ship turns into a streaking fireball}
Obi-Wan: My brain just broke.
R2-D2: That's the spirit!