Docking

As well as Birthing ports (Manual) the ISS also has "Docking" ports for automatic arrival of spacecraft.

The Russian side has 4 docking ports. Usually occupied by 2 Soyuz, 1 or 2 Progress freighters or an automated ESA ATV vehicle.

The US side has three PMAs (Pressurized Mating Adapters). One connects the US and Russian segment together and is permanently occupied.

PMA can adapt a CBM (Common Berthing Module) port to become a docking port (HTV, Cygnus and Dragon use a CBM since the 'door' is wider and they are berthed by the Canadarm2)

International Docking Adapter IDA

IDA for crewed spacecraft to automatically dock with the station. The large metallic ring, which measures 63 inches in diameter, will be installed on the Harmony module where the Bigelow BEAM currently is.

The ISS will have two IDA added

The ring is crucial for the future of NASA’s Commercial Crew Program — an initiative that tasks private companies with building and operating spacecraft that can transport astronauts to and from the ISS. Both SpaceX and Boeing, the companies contracted through the program, are currently developing these space taxis for NASA. SpaceX is updating its current Dragon cargo capsule into a crewed vehicle aptly named Crew Dragon, and Boeing is creating its own capsule, the CST-100 Starliner. Those are supposed to launch for the first time with people on board in late 2017 and early 2018, respectively(both now delayed by 6 months).

 Note IDA1 was destroyed in a SpaceX launch accident in 2015

Androgynous Peripheral Attach System(APAS) Docking Interface 

APAS docking ring can mate with any other APAS docking ring; both sides are androgynous(partly male and partly female). In each docking there is an active and a passive side, but both sides can fulfil either role.

Redwire Space (formally QinetiQ Space)

New proposed international Docking system

  International Berthing Docking Mechanism  IBDM


IBDM is fully redundant and compliant to the International Docking System Standard. It can be used in the following applications: