Vacuum cementing. That's what it's called. Vacuum cementing.
When I was a kid, my mother used to pick me up after school every day. Always at the same time, always at the same spot, a smile and a wave, leaning over to push the door open for me, asking me about my day. Then one Tuesday afternoon she got a flat tire and couldn't get dad on the phone; I sat for an hour, panicked, alone, wondering if I'd ever see home again. It's the things you take absolutely for granted that, when they fail, can absolutely ruin you.
Doors are like that. You open a door, you go through; you think nothing of it. If it's locked, you use a key. If you have no key, you knock, and someone lets you in. If no one's home, no big deal, you come back later.
In space, the air is inside and you need to get inside with it before your tanks run dry, and there's no coming back later. If the hatch doesn't work, because the parts have cold-welded together, you are well and truly fucked.
Anyway, I'm attached to the umbilical. Come get the body when you can.