operation
On demonstration mode, the view point is on the satelite orbit.
And system is simulating the motion of the shaft.
When the participant touches the shaft, the program switches over to interactive mode.
And the view point begin to move slowly to the core of the Earth.
The view point breaks-through the surface of the Earth. And it reaches to the inside of the Earth.
After that, the view point keeps moving on around the core under the influence of motion of the shaft.