Radial Control

Handwaving Warning!

Both the rotor and the track must be positioned vertically and laterally with extremely high precision - they must not drift more than millimeters from each other.

Consider both the rotor and the track as "radial momentum banks", which should be managed to millimeter-per-minute accuracy. The rotor can only be deflected by the integral of forces from the track it passes, but must never ever collide with it; the track is equally-and-oppositely deflected by the integral of the passing rotor forces, as well as rotary movements of the meteor bumpers, small actuator forces launched towards the ground, and very large actuator forces launched from the ground, tens of seconds before.

Rather than rely on global models and giant calculations, a "local momentum market" will operate at kilometer scale along the loop, moving small deflections downstream via the rotor. If section N is displaced a few micrometers to the left, it may pull the right-displaced section of rotor to the left, to decellerate with in a right-displaced section of the track downstream. The global process will be (very slowly) managed through ground cables, though those must also manage wind loading, and predict future loads.

That is all handwaving. There is not enough bandwidth to provide local controllers with the global state of the loop; the controllers know their local position and momentum needs, combine those needs globally into "momentum market signals", and read those combined signals to decide what to do. The market must include effects of broken controllers, broken motor coils, etc., adding those effects to the global market signals.

The server-sky positioning system can "listen laterally" to individual controllers broadcasting damage or extreme offset warnings, and provide additional computing and control information. The server-sky system will store millions of simulation-generated templates for extreme challenges and responses; the simulated loop, anticipating future challenges, will compute for thousands of hours for every hour of real time loop operation.