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 there's no lock 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.
I mean, if you have the ability to build a spacecraft and get there, you've already overcome far larger barriers. Any physical security on the door is going to be comparatively irrelevant as a barrier.
Locks, like walls and other passive defenses, aren't designed to stop people. They're designed to keep basically-honest people honest and slow down the rest to the point where other things, like people, can deal with them.
The highest safe rating here against burglary is 30 minutes of resistance against someone equipped with suitable tools (like, cutting torches and such).
If you can get up to the ISS, it's a pretty safe bet that nobody's going to show up in 30 minutes to do anything about you entering.
Didn't some of the old russian capsules have a gun as standard to shoot any dangerous wildlife when they landed in Siberia? Not sure if that has continued, probably not a good idea anyway!
Well, yeah. If you wanted to take them out all you'd have to do is launch a rocket and rendezvous with the station at high relative velocity. Even low velocity would be destructive. There is no missile defense for space assets.
If You Do the Space Crime, You May Do the
Space Time
International Space Station Intergovernmental
Agreement
Commercial space flights from the United States have included at least one purely private visit to the International Space Station (ISS), a permanently inhabited research-oriented facility in low Earth orbit cooperatively operated by the United States, Member States of the European Space Agency, Russia, Canada, and Japan. Criminal conduct on the ISS implicates an ISS-specific agreement. Modifying and displacing an earlier agreement, the 1998 ISS Intergovernmental Agreement (IGA) signed by the
governments of the cooperating countries provides that, in general, each country retains “jurisdiction and
control” over (1) the “flight elements” or areas it provides and registers in accordance with the agreement
(for instance, the habitation module provided by the United States); and (2) “personnel in or on the Space
Station who are its nationals.” In other words, unless a more specific provision of the IGA applies, each
signatory retains jurisdiction over the areas and personnel it has provided to the project.
So it sounds like basically, from a criminal jurisdiction standpoint, the ISS is a bunch of little territories, made up of bus-length modules.
So if you go through the ISS grabbing stuff, you're probably now committing crimes in US territory, territory of European states, Russian territory, Canadian territory and Japanese territory.