The connection between 2 S/C:

For a good connection on S/Cs there must be flanges and pins that will permit a selfalignment. This action will be helped by a group of trhuster. The astronauts in S/C manned must follow the activities and vent the cavity that has been formed after connection. To avoid the loss of the air, each S/C must made in block compartments.

When the alignment is done and there isn't a loss of air in the vacum of the space. The astronauts can open the hatch and complete the connection screwing the fastners that are supplied.

In any case the S/C manned must have the arm to catch and approach the S/C unmanned.