The Trainee Got Better. It Still Cannot Fly Alone.
I ended The Engineer and the Trainee with a plan: roll out the shielded pilot, relabel every visited state with MPC, retrain, and see whether the trainee could finally fly on its own. That is still the plan. But before getting there I did something lazier, and the result was more interesting than I expected. I also fixed something that had been bothering me every time I watched a flight. The same recorded flight as last time, re-run with a smoother controller and a retrained model. The engine loses 60% of its thrust at ten seconds, the estimate falls to 40%, and the shield now steps in on about one command in eight instead of one in three. The lander had the shakes Watching a descent, the ship twitched. Not a rendering artifact — the controller really was changing its mind. I measured it: over 30 flights the beam search picked a different command on 77.7% of decisions. Every fifth of a second it re-derived the whole plan from scratch, and when two commands were nearly tie...