In this answer I saw Figure 35 of the encyclopaedic ISS Interface Mechanisms and their Heritage also shown croped below, and in this answer I see the second image (though an SE/imgur bug shows it with a black background in reduced size). Click for larger sizes or visit the links.


  1. What does the mating fixture on the "porch" module look like?
  2. What are the 20 dark circles in the square inset? Are these feedthroughs that connect cables and tubes to the porch?
  3. What are these coarse alignment guides bumping up against during "coarse alignment"?

enter image description here

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1 Answer 1


The "porch" (formally the JEM-EF (Japanese Experiment Module - Exposed Facility)) had a matching connector on it that mated with the connector in the pictures above. This picture shows the shuttle arm holding the JEM-EF and the mating connector.

enter image description here

The coarse alignment guides on the two connectors interface with each other; the circles are electrical and data connectors.

The most interesting thing about this connection was the differing philosophies between JAXA and NASA regarding the process of connecting the JEM-EF to the JEM-PM (Pressurized Module).

In a cursory fashion, the process could be described as

  1. Robotic arm places JEM-EF in mating position
  2. Crewperson sends command to mate interface
  3. A short time elapses while mechanisms drive
  4. Crewperson receives indication that interface is mated

NASA wanted to know what troubleshooting telemetry was available if #2 was done and #4 never happened. JAXA's answer was: None. The mechanism was well designed, well built, and well tested, there is no reason it won't work.

Discussions ensued.

The upshot was that the shuttle commander ended up being tasked with exposing the pertinent cabling under the JEM-PM panels, hooking a Fluke multimeter ammeter attachment around the pertinent cable, training a video camera on the multimeter screen and downlinking the image to the control centers. So the ground could watch the amps on the mechanism as it drove.

The mechanism worked perfectly.

Source: personal experience

Photo source: NASA

  • 1
    $\begingroup$ ah, but if the mechanism hadn't worked perfectly, the information may have had some value $\endgroup$
    – user20636
    May 29, 2019 at 7:57
  • $\begingroup$ Not saying either side was right or wrong. Cultural difference. $\endgroup$ May 29, 2019 at 9:43
  • $\begingroup$ absolutely, but the way I read it, it suggested NASA's approach was unnecessary. $\endgroup$
    – user20636
    May 29, 2019 at 11:46
  • 1
    $\begingroup$ Somehow I missed responding to this answer; I think I planned to ask a follow-up question, then got distracted. I do remember enjoying the photo and the story of the different philosophies. Thanks! $\endgroup$
    – uhoh
    Jul 7, 2019 at 22:40

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