Scheduling Kerbals from mission control to do their own missions, like repairing solar panels or wheels, doing burns, Launching vehicles, but is heavily dependent on their Stupidity and Courage. should someone laugh at a joke too long, or spill their coffee in their lap, they may become distracted and get into an undesirable orbit, Break something else in the process, etc, fail their tasks. There is also always the chance of doing it right, and possibly doing better than you could. They can roam planets and moons, pick up samples, and do science. You can always pick back up the controls of any Kerbal you desire, and do everything you can do now, or leave Kerbals to sit and do nothing, as they do now.