I heard that most of a rocket's power is used to get out of the atmosphere. So I was wondering if it would it work to send a very low powered rocket (maybe even something that was simply shot using compressed air) up ~50 km to the edge of the atmosphere (on the high altitude balloon) to be launched there? Would something like that be able to get into orbit? Or even go to the moon?

I know next-to-nothing about rockets, so I hope this doesn't sound like a dumb question :)

  • $\begingroup$ Not about balloons but related: space.stackexchange.com/questions/744/… $\endgroup$
    – ben
    Apr 24, 2019 at 2:21
  • $\begingroup$ This is a question about a technique for launching to space starting at 50 km. It seems perfectly on-topic to me. $\endgroup$
    – uhoh
    Apr 24, 2019 at 4:39
  • $\begingroup$ I'm editing this question to remove the "homemade rocket" part. We don't answer questions about them because of danger, legality, and liability concerns. Because it's not essential to the question, I am removing that language. $\endgroup$
    – DrSheldon
    Apr 24, 2019 at 7:07
  • $\begingroup$ related: space.stackexchange.com/questions/5473/… $\endgroup$
    – Manu H
    Apr 24, 2019 at 7:38

1 Answer 1


To a first approximation, space launch to orbit is speed, not altitude.

Your balloon would supply no speed to speak of. Your rocket would have to supply about 8 km/sec to get into a low Earth orbit, so compressed air will likely not do it.

Launching from a high altitude could have some advantages (like getting above the dense part of the atmosphere) - it's been done by rocket/balloon systems called 'rockoons'. But nothing will take away the speed requirement if you wish to go to orbit.

  • $\begingroup$ Good to know. Thanks for the explanation. How to get something to go fast, then that is the question :) And the rockoons link is also very interesting -- thanks again. $\endgroup$
    – zoecarver
    Apr 24, 2019 at 1:23
  • 2
    $\begingroup$ That is what rocket boosters do. No one has come up with a better idea yet that actually works. $\endgroup$ Apr 24, 2019 at 1:23

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