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.
Apparently the Space Shuttle originally had a handle for opening the door that was found after the shuttle entered use to have a bad habit of instilling a bit of "call-of-the-void". They eventually added a padlock. Also, it should be noted that these doors are not Star Trek-like sliding doors with a bunch of electronics. They're much more like submarine bulkheads with big-ass mechanics, as I understand it. This was on the shuttle, but I think the design logic of the ISS was inherited from the space shuttle.
User TidalWave explains how hatches in general on the ISS are not accessible from the outside. They're opened from the inside. I would assume that some exceptions probably exist for edge cases. They must have had a way to get in the first time, for instance. But by and large, it appears that the ISS is not accessible from the outside.
They must have had a way to get in the first time, for instance.
Not necessarily. There are lots of comparisons to submarines but it's more comparable to airplanes. Part of the security on a plane is that it is physically impossible to open the door while the plane is flying. The pressure difference between the pressurized inside and thin air outside would require superhuman force to open.
In a similar vein, when the ISS was constructed it wasn't initially pressurized. This would make opening the door from the outside trivial from a pressurization standpoint. As long as the only means to pressurize it could be triggered from inside, there'd be no way it would be pressurized without someone inside.
Is it physically impossible or physically impossible for a human? Obviously something can punch a hole through it, but is the material not strong enough to sustain the force needed for it and to hold together?
Interesting. But surely they must have had a plan to recover the station if crew were all incapacitated? With it now being near end of life it doesn't matter as much, but early on when billions had been invested? They surely wouldn't have canned the station in event of a catastrophic air leak?
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.
"Lockpicking lawyer here, and this one is a doozy"
When they eventually deorbit the space station they'll need a way to close and lock the door from the outside when everyone else is out.
Yes, they won't need an atmosphere if there are no people on board but undocking the station side hatch open would cause it to vent the atmosphere and anything not tied down. This could cause the station to spin uncontrollably and potentially do damage to the return craft with the crew on board.
So there must be some sort of way to manipulate the lock from the outside on at least one of the docking ports.
This would also be necessary in an event where they needed to evacuate the station.
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.
On occasion they put a padlock on the inside. There was an incident where a guy was suicidal, because his lifetime project was cancelled while he was up there.