They have open applications for this science/sci fi tracker. The application really isn't that hard if you can get into TI you can get into sciencehd :P. And just to note they have a 3 gig a month rule but if you stay active in the forums or irc room and download some and upload some they let the rule slide. You can also upload just follow their naming rules which again isn't hard there is a tutorial and there is a support room in IRC that have the staff help you out with renaming. So why sciencehd and not the other documentary sites? Well they have their own encoding team for one that releases exclusives to that tracker only and its also incredibily easy to keep a good ratio there. They have a credit system, trivia, etc.