Bacta is a medical substance in the Star Wars universe that has amazing healing properties. Bacta can rejuvinate even the dimmest spark of life. Luke Skywalker got immersed in a bacta tank after spending the night outside on Hoth. Bacta also comes in bandages and smaller doses for local application. It some sort of bacteria and is produced on Thyferra by two rival clans. Some people are alergic to bacta, which generally makes life difficult for them.