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Jul 27, 2016

Standard Spacecraft Docking Port (IDSS)

If you are going to build the latest and greatest spacecraft you might want to have a standard docking port in it .. so that it could dock with all possible space stations and crafts. Looks like NASA and other national organizations have joined their efforts and created a new standard called "International Docking System Standard" (IDSS). It is available for anybody to be downloaded in this link.

Picture of the IDSS International Docking System Standard docking port

Here is a YouTube video about the principle of the docking port.


The docking connects two identical rings together. So all IDSS ports can dock with each other (there are no male or female versions, etc.). Here is a general view of the docking.

Standard Spacecraft Docking Port (IDSS) Principle

The maximum ball that can be fed through the port is 800 mm diameter .. the outer ring diameter is 1200 mm. It has 3 guide petals which latch with the capture ring. In each petal there is a mechanical latch which will lock with the latch striker in the capture ring automatically. The 3 petals interleave with their counter part petals. All together 6 latches will lock in the soft capture system (SCS). Here is a general view of the port.

IDSS Standard Docking Port

The docking happens in several phases;

  1. Soft Capture
  2. Hard Capture
  3. Electrical Connection

The soft capture system (SCS) makes the initial mechanical connection with soft forces to be later connected harder with the hard capture system.

The Hard Capture System (HCS) performs the final structural mating between the two
vehicles, establishing a connection capable of withstanding atmospheric pressure
combined with the loads from planned mated operations of the two spacecraft. The hard capture is based on pins and hooks.

The final IDSS docking is based on hooks.

There are active and passive hooks in each slot. The active hooks will pull the passive hooks.


Additional to the mechanical docking the standard also defines an electrical connector. The electrical connectors are to be connected after the full mechanical docking is done with some mechanisms. Here is a picture of the electrical connector.

IDSS Electrical Connector pin layout

For additional details consult the IDSS standard.


/1/ International Docking Standard

/2/ NASA Docking System

/3/ International Docking System Standard

/4/ Androgynous Peripheral Attach System

/5/ International Berthing and Docking Mechanism

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