Having deprived the Kilrathi fighters in the system of any chance to refuel, the final mission in Valgard sees the remaining enemy fighters launching a final, desperate assault against the Tiger’s Claw herself. Win, and go on to the victory system. Fail, and go into retreat. Lose, and drift in your fighter until you either run out of oxygen, are captured by the cats, or eat a round from your service pistol.
This mission works out to be fairly simple: keep the Claw, and yourself, from dying. That’s it. Fortunately, the Claw can take quite a bit of punishment. Provided you don’t take too much time killing each wave, things should work out just fine.