After 1992–1993 and the Russian integration into the International Space Station Alpha project,[3][4] this NASA docking design abruptly disappeared from all concepts.

The PMAs are pressurized and heated from the inside, and they allow for power and data communications transfer through docking rings and external connections.

On STS-88, the crew used the shuttle's robotic arm to attach the Zarya control module to PMA-1, which was already connected to the aft berthing port of Unity.

PMA-2 is mounted on the forward port of the Harmony connecting node, and was used when Space Shuttle orbiters docked at the ISS.

It was outfitted with Station-to-Shuttle Power Transfer System (SSPTS) hardware to allow the shuttles to stay docked longer to the space station.

Two days later, the combined package of Harmony and PMA-2 was moved to its final location, the forward hatch of Destiny.

[17] As of 2020, PMA-2 is expected to stay berthed at the forward port of Harmony with the IDA connected for the remaining duration of the ISS.

PMA-3 was moved in March 2001 to Unity's port berth by the crew of STS-102 to make room for the docking of the Multi-Purpose Logistics Module (MPLM).

[21] On August 30, 2007, PMA-3 was returned to the nadir port of Unity to make room for the temporary docking of the Harmony (Node 2) module that was delivered by STS-120.