Square Roll Sensitive Docking Port

To perform asteroid drilling and later to allow ships inside its cavern you need not only the Hatch, but also a special docking port: the Square Roll Sensitive Docking Port. Aside from its enormous size and strength this port has one very important feature: two ports of this kind can only be docked to each other in the correct orientation; specifically, with a relative roll of no more than 0.25 deg. Such precision is not so hard to achieve as at a relative roll of ~25 deg magnetic locks are enabled, pulling and rotating the docking ship into the right orientation.

To help a pilot to easily find the right orientation in space all such ports are equipped with the indicator green lights:

Two such ports are provided as separate parts: the Square Roll Sensitive Docking Port itself, which main purpose is to connect Asteroid Hatch to other machinery and the Roll-Sensitive Docking Port Adapter that can be used to haul that machinery using the standard 2.5m form factor ships:

The adapter is also equipped with a battery, reaction wheel and a powerful spotlight.