What is the maximum final relative speed of two spacecraft docking? Say, a supply ship docking with the ISS.

I imagine the incoming ship would try to break as much as possible, but there must be some residual speed.

It's probably dependent on the kinds of the two spacecraft. I'm fine with just a rough idea, i.e. 1 m/s, 10 cm/s, etc

(question was inspired by answering How to plot a Clohessy Wiltshire trajectory on MATLAB?)


We can put an upper bound on this by looking at the requirements for relative velocity in the International Docking Standards.

Here is a screen shot of the relevant page. You can see the closing velocity upper limit is 0.1 m/s.

enter image description here

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    $\begingroup$ So, there actually is a website internationaldockingstandard.com . You live and learn. Thanks for the answer! $\endgroup$ – Everyday Astronaut Feb 23 '18 at 19:32
  • $\begingroup$ Huh. 0.1 m/s contact speed seems... bold. $\endgroup$ – Russell Borogove Feb 23 '18 at 21:57
  • $\begingroup$ If 0.1 m/s contact speed seems... bold, what is about 0.05 m/s? 0.05 m/s < contact speed < 0.1 m/s. $\endgroup$ – Uwe Feb 24 '18 at 9:33
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    $\begingroup$ I think 0.05 is the lower bound. You have to get there, after all. $\endgroup$ – Organic Marble Feb 24 '18 at 16:52
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    $\begingroup$ The lower bound is about ensuring the mechanism latches. Ish. I think the petals in particular depend on the incoming spacecraft having residual momentum so it can be guided into the proper ending position. (I've worked on the standard in question, though not on that part of it) $\endgroup$ – Erin Anne Feb 26 '18 at 4:32

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