Which particular piece of hardware has crossed the Karman line most often?

By hardware I mean anything other than organisms.

  • 13
    $\begingroup$ Do you mean the physically same piece of hardware or the same model of something that's been built multiple times? $\endgroup$
    – Dragongeek
    Commented Dec 4, 2019 at 9:08
  • 5
    $\begingroup$ That, obviously, would be one of the Shuttles (less the tiles, of course). $\endgroup$ Commented Dec 4, 2019 at 9:26
  • 4
    $\begingroup$ I suppose there could be an aircraft that's done ballistic trajectories to 100 km more than once, but not sure if it could be more times than a Shuttle. How did the X-15 control attitude above the Kármán line? $\endgroup$
    – uhoh
    Commented Dec 4, 2019 at 9:56
  • 2
    $\begingroup$ My guess, which I'm having a bit of trouble backing up with actual data, is that we're looking for something doing some elliptical de-orbiting aerobraking over multiple passes. $\endgroup$
    – Roger
    Commented Dec 4, 2019 at 18:36
  • 9
    $\begingroup$ I'd be very unsurprised if a piece of Soyuz equipment, like the survival box, was retrieved from the landed capsule and reused on next launch enough times to breach the record. $\endgroup$
    – SF.
    Commented Dec 4, 2019 at 22:47

1 Answer 1


The Space Shuttle Discovery has been to orbit a total number of 39 times, more than any other shuttle vehicle (source: Wikipedia). Contrasting that to other candidate objects:

  • Space Shuttles Atlantis, Columbia, Endeavour and Challenger flew 33, 28, 25 and 10 missions, respectively.

  • Spacelab pressurized module LM1 flew a total of 10 times.

  • Falcon 9 first stage B1048 has been used a total of 4 times and has not exceeded the Karman line in any of those flights
  • The X-15-1 flew a total of 81 times, however it never exceeded the Karman line as the highest altitude it ever reached was 267,500 ft. X-15-3 did exceed the Karman line twice.
  • The X-37b has flown a total of 5 times, however a single vehicle has only flown 3 times
  • 23
    $\begingroup$ I still wonder about piece-parts. The SSME that flew the most missions flew ~20 times. But some laptop, swizzle stick, etc...who knows? Hard to track down. $\endgroup$ Commented Dec 4, 2019 at 17:25
  • 3
    $\begingroup$ Other things that have been to space multiple times: Westar 6 / AsiaSat 1, which was retrieved by the Shuttle and subsequently relaunched; several pieces of SpaceX hardware have been reflown above the Karman line (one Dragon capsule was reflown, as was one fairing); and if you count humans as objects, Jerry Ross and Franklin Díaz have both been to space 7 times. $\endgroup$
    – Skyler
    Commented Dec 4, 2019 at 18:03
  • 4
    $\begingroup$ @DiegoSánchez you can see a spreadsheet showing the missions of all the orbiters here: space.stackexchange.com/a/25415/6944 $\endgroup$ Commented Dec 4, 2019 at 20:26
  • 6
    $\begingroup$ I wonder if it could be something mundane like the containers they use to ship supplies (food, etc.) to the ISS? I'd assume they get sent back empty (or possibly with waste materials), since they'd just be wasting the limited space up there, and possibly they'd get reused on future resupply missions. $\endgroup$ Commented Dec 4, 2019 at 21:48
  • 6
    $\begingroup$ -1I think that by asking "Which particular piece of hardware..." the OP is indeed asking specifically about individual bits, rather than only for entire spacecraft. $\endgroup$
    – uhoh
    Commented Dec 4, 2019 at 22:25

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