A long time ago in a SF galaxy not so far away....

Just a little bit of brain storming here:<br /><br />Question: You want to write an adventure/campaign set back in the time line to a period long before anything in the published modules and contact with the sathar, maybe even before the core 4 meet, what do you use for opposition?<br /><br />Note: there will be some technical issues like things breaking or not working right and some role play parts but you need some shoot 'em up stuff for excitement.<br /><br /><br />