Has America thought of a fully unmanned Main Battle Tank for the Future?

I figured with most nations getting rid of loaders whilst adding auto loading systems. Now the latest seems to be removing all crew from the turret and having a Commander and Driver in the hull front (Like T95 Tank and US future Tank).I say why not have a totally unmanned Main Battle Tank (like a tank version of the Predator Drone). Would there be problems with calculating terrain or are there systems out there already such as Mars Rover or unmanned robots I've seen on Future Weapons. What are your thoughts, Cheers John.