Scott Manley on Twitter: "One question I get asked a lot, and I don't honestly know the answer to, is why the pressurized mating adapters on the ISS have this offset axis.
![S114E5399 - STS-114 - Soyuz spacecraft docked to Pressurized Mating Adapter (PMA) 1. - PICRYL Public Domain Search S114E5399 - STS-114 - Soyuz spacecraft docked to Pressurized Mating Adapter (PMA) 1. - PICRYL Public Domain Search](https://cdn10.picryl.com/photo/2011/07/21/s114e5399-sts-114-soyuz-spacecraft-docked-to-pressurized-mating-adapter-pma-cdc4bc-1024.jpg)
S114E5399 - STS-114 - Soyuz spacecraft docked to Pressurized Mating Adapter (PMA) 1. - PICRYL Public Domain Search
![KENNEDY SPACE CENTER, FLA. -- The Pressurized Mating Adapter-1 (PMA-1), scheduled to fly on Space Shuttle mission STS-88 is undergoing processing in the Space Station Processing Facility (SSPF). A PMA is a KENNEDY SPACE CENTER, FLA. -- The Pressurized Mating Adapter-1 (PMA-1), scheduled to fly on Space Shuttle mission STS-88 is undergoing processing in the Space Station Processing Facility (SSPF). A PMA is a](https://c8.alamy.com/comp/2BYX3HN/kennedy-space-center-fla-the-pressurized-mating-adapter-1-pma-1-scheduled-to-fly-on-space-shuttle-mission-sts-88-is-undergoing-processing-in-the-space-station-processing-facility-sspf-a-pma-is-a-cone-shaped-connector-that-will-be-attached-to-node-1-the-space-stations-structural-building-block-during-ground-processing-sts-88-is-the-first-international-space-station-assembly-flight-2BYX3HN.jpg)
KENNEDY SPACE CENTER, FLA. -- The Pressurized Mating Adapter-1 (PMA-1), scheduled to fly on Space Shuttle mission STS-88 is undergoing processing in the Space Station Processing Facility (SSPF). A PMA is a
The Pressurized Mating Adapter PMA -2 for the International Space Station ISS awaits being mated with Node 1. — Google Arts & Culture
![The Space Shuttle Discovery is seen docked to the Pressurized Mating Adapter (PMA-2) on the International Space Station in this NASA image taken by an unidentified astronaut during the second session of The Space Shuttle Discovery is seen docked to the Pressurized Mating Adapter (PMA-2) on the International Space Station in this NASA image taken by an unidentified astronaut during the second session of](https://c8.alamy.com/comp/W0MBBB/the-space-shuttle-discovery-is-seen-docked-to-the-pressurized-mating-adapter-pma-2-on-the-international-space-station-in-this-nasa-image-taken-by-an-unidentified-astronaut-during-the-second-session-of-extravehicular-activity-during-nasa-mission-sts-120-upi-photonasa-W0MBBB.jpg)
The Space Shuttle Discovery is seen docked to the Pressurized Mating Adapter (PMA-2) on the International Space Station in this NASA image taken by an unidentified astronaut during the second session of
![Human Spaceflight on Twitter: "The image used above is an archive picture and does not show the International Docking Adapter-2 – it was installed on the Pressurized Mating Adapter-2 in 2017.… https://t.co/PH8ON4Lglj" Human Spaceflight on Twitter: "The image used above is an archive picture and does not show the International Docking Adapter-2 – it was installed on the Pressurized Mating Adapter-2 in 2017.… https://t.co/PH8ON4Lglj"](https://pbs.twimg.com/media/EzuXcluXIAQAx8N.png)
Human Spaceflight on Twitter: "The image used above is an archive picture and does not show the International Docking Adapter-2 – it was installed on the Pressurized Mating Adapter-2 in 2017.… https://t.co/PH8ON4Lglj"
![08/18/1997 --- The Pressurized Mating Adapter-1 PMA-1, scheduled to fly on Space Shuttle mission..., Stock Photo, Picture And Rights Managed Image. Pic. GXC-S10752 | agefotostock 08/18/1997 --- The Pressurized Mating Adapter-1 PMA-1, scheduled to fly on Space Shuttle mission..., Stock Photo, Picture And Rights Managed Image. Pic. GXC-S10752 | agefotostock](https://previews.agefotostock.com/previewimage/medibigoff/638e332b169862b8d33983833f480632/gxc-s10752.jpg)
08/18/1997 --- The Pressurized Mating Adapter-1 PMA-1, scheduled to fly on Space Shuttle mission..., Stock Photo, Picture And Rights Managed Image. Pic. GXC-S10752 | agefotostock
![10/04/1997 -- The Pressurized Mating Adapter 2 PMA 2, at left, Stock Photo, Picture And Rights Managed Image. Pic. GXC-S10953 | agefotostock 10/04/1997 -- The Pressurized Mating Adapter 2 PMA 2, at left, Stock Photo, Picture And Rights Managed Image. Pic. GXC-S10953 | agefotostock](https://previews.agefotostock.com/previewimage/medibigoff/b08424f12dc12f842079824f82183671/gxc-s10953.jpg)
10/04/1997 -- The Pressurized Mating Adapter 2 PMA 2, at left, Stock Photo, Picture And Rights Managed Image. Pic. GXC-S10953 | agefotostock
![STS098-331-001 - STS-098 - Common Berthing Mechanism (CBM) on Pressurized Mating Adapter (PMA) 2 - U.S. National Archives & DVIDS Public Domain Search STS098-331-001 - STS-098 - Common Berthing Mechanism (CBM) on Pressurized Mating Adapter (PMA) 2 - U.S. National Archives & DVIDS Public Domain Search](https://cdn10.picryl.com/photo/2011/07/21/sts098-331-001-sts-098-common-berthing-mechanism-cbm-on-pressurized-mating-4b5950-640.jpg)