First piece of advice I will give you is. Don't stress over the game. Relax and enjoy it. You'll get good and then the missions will come. I've played both games for years. I got the original with my computer for heavens sake(1996). It's an amazing and addictive game to play.
Now about your little problem. First make sure your a good boy with the Miranu. Then I'm pretty sure there is a mission where the Trade Corp. asks you to ship some purple eel things to some Igadzra colony. You'll recieve something in return. Now, after this I'm pretty sure the Nebula Exploration string will begin. Hope that helps.
Don't worry about people saying things about you because you post topics asking for help. That's what this forum is for. So feel free, as long as you don't spam. Good luck and have fun.
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"God is dead." - Friedrich Wilhelm Nietzsche
(This message has been edited by grand admiral thrawn (edited 12-25-2001).)