Trying to remember the name of a game

I believe I played it on my IIsi, if that helps with the age. It was a sci-fi game where you flew a ship around, exploring stars, and their planets, mining, searching for artifacts, interacting with aliens, upgrading your ship and uncovering some great meta-mystery.

Ring any bells? I remember I stopped playing it because I lost the key wheel (or whatever copy-protection system they had).

Thanks,

Nathan