speculation and pondering in the Pod Bay has got me wondering; What has been the largest variety of independent spacecraft types simultaneously, docked, clustered or otherwise attached in space?

These attachments should be at least fairly rigid; a bunch of little things on a string should't be the primary answer, nor should a cluster of separate payloads before deployment nor a whole bunch of needles count at all.

  • $\begingroup$ How does ISS count? Is it a single 'item' or the sum of its parts in your question here? Node1, Node2, Node 3, Columbus, Kibo, Zarya, Zvezda, Pirs, Poisk, Rassvet, (How do you count teh truss? 8 parts?) Quest Airflock, Beam, MPLM. Then layer in visiting vehicles? $\endgroup$
    – geoffc
    Jan 8, 2021 at 2:25
  • $\begingroup$ @geoffc "independent spacecraft" is in the title, but it looks like I haven't repeated "independent" in the body of the text. The failure to repeat “independent” was an error which has now been corrected. Thank you for pointing that out! My guess is that most sections of the ISS would not be characterized as independent spacecraft, or spacecraft at all, by design or by history. I think a workable definition might include an examination of international designator numbers (e.g. Zarya 1998-067A) but exactly how I can't yet say. $\endgroup$
    – uhoh
    Jan 8, 2021 at 2:41
  • $\begingroup$ I still think it will be ISS after a shipment with a bunch of cubesats awaiting release. $\endgroup$
    – SF.
    Jan 8, 2021 at 3:21
  • 1
    $\begingroup$ ISS is strange.. The US segments came as payload in the shuttle bay so I will agree, do not count then. But the Russian elements (minus Rassvet) launched as independent spacecraft and docked becoming part of the station. So perhaps the iSS is then spacecraft before vehicles (Pirs, Poisk, Zarya, Zvezda). $\endgroup$
    – geoffc
    Jan 8, 2021 at 12:18
  • 1
    $\begingroup$ Nauka due maybe this year will launch on a Proton and fly itself to where Pirs is currently docked. Pirs was delivered on a modified progress propulsion module. Last Progress docked to Pirs will leave, taking Pirs with it, freeing up the port. Rassvet came up in the Shuttle bay as the only major exception on the Russian side. $\endgroup$
    – geoffc
    Jan 8, 2021 at 12:57

1 Answer 1


The ISS should count partially at least as 4, since Zarya, Zvezda, Pirs, and Poisk all launched a spacecraft and docked to the complex. Maybe even this year Nuaka will launch and make it 5. (It has been delayed since 2011 so I am being a bit sarcastic on this module).

Then we have as many as 6-7 of the following docked at any time in some combination. With a minimum of 3 vehicles (2 crew, one cargo) docked at any one moment in time.

  • Soyuz
  • Progress
  • ATV (Retired)
  • HTV (Retired, HTV-2 coming soon)
  • Dragon 1 Cargo (Retired - replaced by V2)
  • Dragon 2 Cargo
  • Dragon 2 Crew
  • Cygnus
  • Shuttle (Retired)

Thus ISS would float between 7 minimum to 11 or so at any given time.

  • $\begingroup$ Interesting game, though can we clarify the rule about indepence for Pirs and Poisk? As I understand they were both delivered by modified Progress and in that sense are not different from delivery via shuttle. $\endgroup$
    – Puffin
    Jan 8, 2021 at 14:27
  • 1
    $\begingroup$ But they were launched as one unit, (Pirs + Progress) not INSIDE a cargo bay (Though was there a fairing at all? I dunno. Would the X-37B count then since it launches inside a fairing?) which is distinct from Rassvet. As you say, a fun game. $\endgroup$
    – geoffc
    Jan 8, 2021 at 14:51
  • $\begingroup$ OK, maybe I didn't express that very well. My intepretation would be that Pirs and Poisk are unable to undock alone, or perform translation manoeuvres at all, where as the X37B can, as can the berthed vehicles like Cargo Dragon and Cygnus (detail: do they unberth unassisted?). $\endgroup$
    – Puffin
    Jan 8, 2021 at 15:29
  • $\begingroup$ Dragonv1/Cygnus Unberth by CanadaArm2. To which I would counter, that when launched they COULD. But they discarded that module. So once they were, but then they grew up? This is fun. $\endgroup$
    – geoffc
    Jan 8, 2021 at 15:54
  • $\begingroup$ On reflection I think I would count Dragon/Cygnus regardless of the unberth by CanadaArm. I would outflank the growing-up defence by enquiring whether the command-chain and control system for the Pirs/Poisk translation/docking resided within those modules, as left attached to the space station, or was separated along with the rest of the Progress module. $\endgroup$
    – Puffin
    Jan 8, 2021 at 17:46

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