Bounty Hunter (2nd Edition) is still work in progress. Basically, it's a 'patch' for DND 3rd edition which includes all manner of Sci Fi maddness. Not content with wielding a +6 sword of Maiming? Well try out a Extended range rapid fire flachette rifle with hard wired sniper scope feeding directly into an AI controlled targeting matrix.
Bounty Hunter 2nd Edition includes new SF specific character classes, skills and feats, along with a comprehensive (and fully customizable) range of weapons. Eventually, there will be full rules for designing your own vehicles, but that's going to take time.