tut tut.
I'm guessing (correct me if im wrong) that your using the m5 that you get at the start of the game.
An easier way to make yourself invulnerable is to buy a new ship + a squadron or two of fighters to protect you or maybe even a corvette.
It's pretty simple just type Thereshallbewings when your flying (notice capital "T" hold shift for the T) that will open the script editor. Go to the list of scripts and search for one with something along the lines of... example.. press C to copy the script then call it something like Money. Then go to that script and select it. Inside the script will be a section that says give the player money. Select this and then change number I think it was, to something like 99999999. I can't remember how much I used when I made mine. Then press escape and save the changes. Then in the list of scripts again find your script "money" and when you have it highlighted press R and select null. You will instantly get 999999 credits! Run the script a few times for an unlimeted supply of credits.
This way you can buy many ships to trade with you and to fight for you while you make a getaway in your tradship or whatever weakling sheep you chose.
Sounds complicated but it is pretty easy when you when you know how. (I slapped myself so hard when I found this out I fell off my chair) *Demonstraights*
*Groan*
Although your not invincible physically you are protected by so many ships your as good as bullet proof,

hope that helps
*Groan*
*I have to stop doing that*