You know, “hatch”. But it’s funnier saying door. Could a ship just dock with it, equalise pressure, and open the hatch? Or is there some sort of security? I tend to think ‘no’ because of a macabre situation where the crew are dead and the station is being recovered. But it’s amusing to think in space they don’t need to keep the doors locked.
With the exception of the recent Starliner fiasco, there are never more people on board the station than there are seats on the visiting spacecraft. In the event of a catastrophe, the Soyuz and Dragons function as lifeboats. To leave the station, you need to be able to close the station hatch from the spacecraft side. If you didn’t, the entire station would depressurize in your face when you undocked, which could cause a navigational hazard for the escaping ship.
Therefore, it must be possible to crank the station hatch shut from the visiting vehicle side, and, it stands to reason, the reverse is true.
This is a photo of the space-facing side of Shuttle / Dragon docking port on the station. The middle is a target to assist pilots in manually flying into the port straight and level. It was needed for the shuttle, newer spacecraft have automatic guidance. At 12 o’clock is a handle to help pull the hatch shut. (To open, you push the hatch in.) At 6 o’clock I believe is a socket you can put a crank into to seal or unseal the hatch. At 10:30 is a pressure equalization valve.