Outer Space (itch) (ZoppaZop)

You are in the furthest area of outer space, far away from any planet or intelligent life. Suddenly a group of unknown spaceships appears out of nowhere and starts attacking you.  

You think it could not be worse, but then a technical issue on the board computer occurs, that makes parts of your impressive weapon system unuseable when your tank is full. Less fuel equals more firepower. Operate carefully! Even if getting rid of fuel lets you have access to your better weapons, it might also bring you closer to death. The Enemys you will meet in the asteroid field may not have merci, but ervery now and then they lose one of their power cells, you can use to keep your spaceship alive.

How long can you survive?