Can try upgrading your shields.. man loved this game.
There's no other game that comes close! Except for maybe Starlancer. Can't believe since then there aren't any more games like this. Doh!
Malorie: Thanks for the tips everyone, it took me about ten attempts to get a good run at just the first mission, because an asteroid would always come out of nowhere and kill me in one hit!
Now I've finally realised that dodging up and down can just make you more vulnerable most of the time, because there could be an asteroid right above you that you can't quite see until you move up and hit it...
Now that I've finally figured out just turning left and right to dodge, and only going up/down if there's a wall of asteroids from left to right going towards you, I'm a lot more confident going into the next mission.
That said, on one of the runs, an asteroid managed to hit me from the side which I never even saw... but at least that only happened once in the ten times I had to attempt those darned asteroid fields!