The challenge with rovers is to start with a lego mindstorm system and build a robot that can collect pingpong balls. The students have to design and build there own circuits and all other parts. They work in groups that are divided into a manager, mechanical team, electrical team, and computer team. In the final competition the rovers go head to head to see who can get the most balls in 3 minutes. Starting in 2004 the Rovers were required to be autonomous.