The HTV Small Return Capsule (HSRC) is on the HTV-7 mission to the ISS.

It is a sample return, small capsule, shaped as you would expect, like a small Apollo/Orion/Dragon shape.

It is shipped up inside the HTV in the pressurized section. Assembled by the ISS crew, reattached somehow to the HTV. Then when the HTV is released from the station's CBM port, released by the CanadArm2 to orbit independantly it is then somehow released from the HTV.

The question is, without an EVA the only portion of the HTV available is the hatch door, which mates pretty closely with the CBM internal hatch. I.e. The HTV hatch that faces vacuum and the ISS hatch that faces vacuum are the parts that face each other when it is first berthed.

Then the ISS door is opened, and finally the HTV door is opened.

Is there enough room in that gap for the HSRC? If so, it seems like it must be pretty small.

If not, where is the HSRC actually attached?


1 Answer 1


It mounts on the hatch/CBM interface.

enter image description here


  • 1
    $\begingroup$ Is that then a special HTV hatch,, that has the space for it to fit? Coolio! $\endgroup$
    – geoffc
    Nov 7, 2018 at 17:43
  • $\begingroup$ The linked paper has a lot of good info about what's in the little capsule. $\endgroup$ Nov 7, 2018 at 17:43
  • 1
    $\begingroup$ That is a smaller capsule than I imaged. 0.84m diameter. About 2.5 feet or so across. About 5L of volume. (2 and a quarter big bottles of pop). $\endgroup$
    – geoffc
    Nov 7, 2018 at 17:45
  • $\begingroup$ what? 0.84*(pi*(0.75/2)^2) is a lot more than 5 l. $\endgroup$
    – Hobbes
    Nov 7, 2018 at 18:30
  • $\begingroup$ The payload volume is ~ 5L. $\endgroup$ Nov 7, 2018 at 18:35

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