Mars Rover
A remote-control Mars Rover activity.
I built a little pen for a small robot we were given by Carnegie-Mellon, for some reason. (I didn't do the faux-rock interior - we had an intern do that.)
Anyway, the point of the exhibit was that the little rover had a camera whose images could be seen from the control station on the other side of the column behind the horizon image.
Mission Control. From here, the visitor could give the rover instructions to investigate one of the objects in the crater.
But here's the catch: the visitor could not control the rover in real time, nor could they see the rover directly. Rather, they had to use the rover's cameras to send batches of instructions with a time delay - just like the real Mars Rover.