The question Why isn't there a rocket to launch a single cubesat? has several good answers that explain why there isn't and/or will not likely be one, based mostly on commercial viability, consistent with the gist of the question's text.

Yet one answer cites JAXA's launch of the single 3U cubeast TRICOM-1 into orbit using the “world's smallest orbital rocket” the SS-520-5.

If there are so many good answers explaining why there won't be rockets to launch individual cubesats, one might ask:

  1. Then why is there one and why did JAXA develop it?
  2. What are the long term plans for this launch solution (that shouldn't exist)?

enter image description here enter image description here

Source Click image(s) for full size.

  • 6
    $\begingroup$ The answer to that question was "there's no business case" The answer to this question is "Governments don't need a business case" $\endgroup$
    – user20636
    Aug 4, 2019 at 7:49
  • 1
    $\begingroup$ Governments think about things other than profit, especially strategic considerations. They might be paying to maintain the capability to do anti-satellite strikes. $\endgroup$
    – Roko Mijic
    Aug 4, 2019 at 19:14
  • 1
    $\begingroup$ Or could just be government largesse, jobs program, Japanese pork (like US space shuttle was a pork project) $\endgroup$
    – Roko Mijic
    Aug 4, 2019 at 19:15
  • 4
    $\begingroup$ @RokoMijic I object to your blanket characterization of the shuttle program as a 'pork project'. $\endgroup$ Aug 4, 2019 at 20:05
  • 1
    $\begingroup$ perhaps, but that would take us off topic here. Point is that governments have other motivations than what's efficient, useful etc. $\endgroup$
    – Roko Mijic
    Aug 4, 2019 at 21:25

1 Answer 1


The SS-520-5 launcher is not intended to be an operational vehicle.

  • ... the SS-520-5 was also an experiment to construct a minimum system that can be established with a micro-small rocket and whether future AFSS will be established.
  • ...was conducted as a demonstration of compact and light substrate technology, consumer manufacturing technology, quality assurance technology using COTS technology. We demonstrated technology of Japanese COTS parts companies that can withstand severe launch environmental conditions.
  • Through this development we were able to confirm that the COTS parts made in Japan function with satellites and rockets.This affordable technology can be used for the development technology of low cost rockets.

(AFSS = Autonomous Flight Safety System, COTS = Commercial Off The Shelf)


  • 1
    $\begingroup$ So SS-520-5 was a demonstration of technology. Though it succeeded in putting a satellite into orbit I think that "...is not intended to be an operational vehicle" means it's a technology demonstration and perhaps not a final product. But I'm not sure if this is a complete answer to my question yet, specifically item #2. Are you suggesting that the technologies demonstrated will only be used in much larger rockets and that they will not be using this to launch individual cubesats? Has that been ruled out in any way? $\endgroup$
    – uhoh
    Aug 4, 2019 at 20:04
  • $\begingroup$ your answer here is an excellent match for How do small, spin stabilized launchers follow a Rhumb line? $\endgroup$
    – uhoh
    Aug 4, 2019 at 21:31
  • $\begingroup$ What are they trying to demonstrate? $\endgroup$
    – ikrase
    Nov 5, 2020 at 4:47
  • 1
    $\begingroup$ @ikrase 2nd bullet $\endgroup$ Nov 5, 2020 at 5:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.