Why The Docking Adapters On The Space Station Are Shaped Oddly

There are many docking systems on the International Space Station, reflecting the fact that it's the product of multiple space programs which combined their space station plans into the ISS. The history of the program has lead to some design choices which seem to be strange, until you look at them in the context of the whole program history.
In particular, I often get asked about the pressurized mating adapters at the front of the space station and how the tunnel includes a bend rather than simply going straight through, and of course it's all because of historical choices.

Some further reading on the docking and berthing hardware used on the ISS

[desert-rat]

"that is because of legacy decisions, and it will take more than the occasional bumped head to justify changing out such a large chunk of hardware." Sounds like every meeting within IT

[FuzzyToasterMeister]

Not even the ISS can avoid needing too many dongles.

[robertchandler]

Scott has a gift for clear speech and delivering lots of info quickly. I love how he gets right to the point and wastes none of our time.

[johnpreisler]

The solution is to use oddly-shaped astronauts

[Krakenslayer]

So what you’re saying is you can’t take two magnetic circles, smash them together, and magically transfer green beans through them?

[reactorfour]

This makes me appreciate that the docking ports in KSP are simple, just align the spacecraft with the docking port you’re trying to dock to, move to it slowly and it will pull you to a successful dock. It’s never that simple in real life.

[kevinzheng]

Damn, even INTEL doesn't have so many socket standards.

[TCV]

*Doug bangs his head*
Scott: "Oh damn, better start researching"

[dxkaiyuan]

Wow, the ISS requires almost as many adapters as the new MacBook

[davidlabedz]

Scott, more interesting space history. Could one give more details on how the docking adapter functions??

[thelonelyrogue]

Does the possibility of the unused section coming into use mean that the ISS may need additional storage space added? Imagine, the first module added in years; a closet.

[AskTristan]

In the first renderings of the PMA (option 1 option 4 ~8:25 in your video), it seems apparent that the offset is to avoid the truss structure in both images. This now becomes grandfathered in, so on. Thanks yet again for a great video, Scott!

[aevangel]

"I'm Scott Manley; fly safe"

*proceeds to bump head....*

[icollectstories]

5:02 To my eyes, the kink allowed the windows on the top of the shuttle to view the docking adapter. "The two overhead windows ... provide rendezvous [and] docking ... viewing" from NASA's "Forward Fuselage and Crew Compartment Windows."
Useful for people who mistrust cameras.

[greenetomphson]

gotta love how the two docking modules are "International" and "Russian"

[theelephantandtherider]

if there's one thing that i've learned lately from this channel, is that i dont want to learn how to design space stuff. but, this has come with drastically increased respect for people who just, , , do this stuff.

[SimplySpace]

Thanks Scott. I've been wondering this about the PMA for a while and the payload clearance issue seems pretty obvious now that you point it out. And well, if it ain't broken don't fix it!

[DanielLewycky]

Scott, it makes me so glad to hear you use the metric system in these videos.

[laprepper]

The sheer amount of research you must do to put these videos together is quite impressive, I really love your content 😁😄

[dorbie]

The clearance issue makes sense going forward indefinitely. Any future vehicle could still potentially exploit the asymmetry to get more clearance in their chosen direction.