1
$\begingroup$

Ignoring the challenge of making a 100 km long tube to space,

here's the plan

  • we will need a 100 km long tube and at least a meter wide or less

  • A base which will do the job of creating a vacuum in a volume of at least 30000 meter cube after every launch(how much energy it will need?)

*sealed door connecting the loading room and the tube

how much force will be exerted by the wind entering the tube once the sealed is opened between the loading room and the tube?

what if we don't make it 100 km high, just enough to launch 1kg of package to space? what specs do we need?

Even if we can export 1kg package to space it will be a huge deal cause it obviously costs millions right now

Improve this question
$\endgroup$
5
  • $\begingroup$ You would be better off with a Wonkavator... $\endgroup$
    – user207455
    Commented Jul 4, 2019 at 13:41
  • $\begingroup$ sure, if you would like to take the pleasure of being first wonkavatorer and the first dead human on board $\endgroup$
    – Curious Flower
    Commented Jul 4, 2019 at 13:49
  • $\begingroup$ Sounds about as fun as being forcefully sucked into a vacuum tube that collapses under the stress. $\endgroup$
    – JMac
    Commented Jul 4, 2019 at 13:54
  • $\begingroup$ Do you know what a Wonkavator is? $\endgroup$
    – user207455
    Commented Jul 4, 2019 at 14:04
  • $\begingroup$ Exactly zero force will be applied. Air weighs the same inside the tube as out. You cannot "vacuum" the air out of the tube from the top. At 100km there is already a pretty good vacuum. avs.org/AVS/files/c7/c7edaedb-95b2-438f-adfb-36de54f87b9e.pdf $\endgroup$
    – puppetsock
    Commented Jul 4, 2019 at 14:07

1 Answer 1

Reset to default
2
$\begingroup$

we will need a 100 km long tube and at least a meter wide or less

At least... or less? :-)

A base which will do the job of creating a vacuum in a volume of at least 30000 meter cube after every launch(how much energy it will need?)

Ok, got it. So basically you cap both ends, pump out the air, put in the rocket, and then open the bottom. Is that it?

how much force will be exerted by the wind entering the tube once the sealed is opened between the loading room and the tube?

Very little.

One can easily calculate the initial force, it's simply the pressure of the air you let in vs. the area of the tube. So in the case of a 1m radius tube, it's pi r^2 = pi^2 = 9.8596 ~= 15300 square inches. If you let in normal atmosphere, then 15300 x 14.7 psi ~= 225000 pounds of force.

However, as the "ship" starts to move up the tube, the pressure begins to drop due to the ideal gas law. It won't move far before the pressure is far too small to move the ship against gravity.

So maybe you pump in air to keep it going? Sure, but then you may as well use gunpowder.

Improve this answer
$\endgroup$
1
  • $\begingroup$ Probably just easier at that point to pressurize the column well over atmospheric pressure to extend the air column and make some sort of buoyant floating device. Or just gunpowder; that would definitely be more entertaining for watching launches. $\endgroup$
    – JMac
    Commented Jul 4, 2019 at 17:32

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.