Could the weight of a launch tower or some of a space elevator be mitigated balloons?

Similar to the children's air inflated jump houses could a tower be inflated with hydrogen/helium with different material to offset the weight needed to run a high voltage power line or rail that would also serve as the tether line?

The tower would only carry electricity the vehicle would provide thrust by electric turbine engine or other electric propelling technology.

Location: The most wind calm place on Earth though all the wind columns to minimize wind tension.

Mode of power: https://electronics.stackexchange.com/questions/280558/can-high-voltage-power-lines-em-provide-power-for-drones

Repair: Service tubes can be filled with a helium/oxygen mixture to optimize air weight for repair from with in the superstructure. Chambers are pressured to be buoyant to the elevation of each chamber. A separate internal bladder would lift the structure. During high winds it would just lean over and/or retract.

Can a reusable electric powered blimp stage for launch possible?

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    $\begingroup$ Interesting. So, is the goal of this to reduce the size of the counterweight? Or is it more about reducing the stress on the upper parts of the cable? $\endgroup$ Sep 7 '18 at 19:58
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    $\begingroup$ Your question says "space elevator", and your title says "launch tower". Are you talking about a geosynchronous orbital-speed elevator, or just a tallish tower? $\endgroup$
    – BowlOfRed
    Sep 7 '18 at 21:16
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    $\begingroup$ Rather than fill it with hydrogen or helium, make it held up by internal pressure and use cheap nitrogen. Kevlar would be strong enough to make a pretty tall tower than could support quite a bit of weight. $\endgroup$
    – zeta-band
    Sep 7 '18 at 22:03
  • $\begingroup$ Okay. So, the benefit is that it reduces stress on the cable above, since it's not supporting that first 53 clicks or so? $\endgroup$ Sep 8 '18 at 1:38
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    $\begingroup$ @muze - I can't think of a beneficial edit at this point. I'm wondering about a tall elevator, say, 44K kilometers, and this technique saves the weight of 53 of that 44K kilometers. Considering that the lowest 53 kilometers is the narrowing bottom end of the cable, it seems like the benefit is not very substantial. I'm interested to see further progress on this question, though. $\endgroup$ Sep 8 '18 at 2:41

A space elevator has to be at least 36,000 km long, and many designs are twice that or more because it's easier to extend the cable from the geostationary starting point in two directions at once.

Compared to a cable 36,000 km long, the 50 km you could theoretically reach with the largest balloons ever built is not worth the extra effort.

And it gets worse. The cable is in tension: at 50 km, the cable pulls upwards, not towards the ground. So there's no need for extra lift at that altitude.

So there is no benefit to using balloons for a space elevator.

  • $\begingroup$ You are the only answer I could award although I disagree with this answer and a launch skid that goes to 50km could be useful if not reusable for the first stage. $\endgroup$
    – Muze
    Jan 15 '19 at 0:06

An inflatable structure that is lighter than air is going to be trading reduced strength needed due to buoyancy for increased strength needed due to sail area of the structure being pushed by the wind.

Not finding any helpful math at the moment for sail area vs lifting capacity but the fact that a 1000kg lift capacity balloon needs needs more than 1000kg to anchor it in anything but the lightest of winds would suggest this is a problem. Though a tethered balloon might be part of a space elevator assembly project where the weather is carefully chosen for the flight/s.

Also note that one thing the orbital structure at the top end of an elevator does not want is to be whipped around by wind forces at the bottom end of the structure propagating up.

One data pointis that the global helium production is around 175 million cubic meters and each cubic meter lifts around 1kg at sea level, which places a pretty hard upper limit on helium lifted mega projects.


Could first half of the space elevator weight be mitigated balloons?

When most people here say "space elevator," they are not talking about a tower that would need a strong foundation or strong columns or balloons or anything else to support its weight. They are talking about a big rock that would be tethered to the Earth by a long cord, and it would have a strong anchor drilled deep into the Earth to hold it down---to keep it from being flung away into the Solar System.

A space elevator would not be built up from the Earth. It would be built down from orbit.

It also would need to be somewhat longer than what you show in your pictures. Not 53 km, but as @Hobbes said, more than 36,000 km.

The main jumping-off point would be a bit less than 36,000km from the center of the Earth. That's the level where everything near the cable would be in a circular orbit around the Earth. That's the level where it would make sense to assemble the components of a big interplanetary or interstellar space ship before launching it on its way.

Jumping off at, say 400km (around the height of the international space station), you would immediately fall almost straight to the ground. You could haul a spacecraft up to that level, and launch it from there, but you still would need a pretty big rocket to put the spacecraft into Earth orbit because the cable, at that altitude, would only be moving at a tiny fraction of orbital velocity.

  • $\begingroup$ This make much sense to me but I should have said tower+ $\endgroup$
    – Muze
    Sep 12 '18 at 20:28

I found this on wiki and in a comment on another question on SE but this tower is inflatable with modifications I believe another 40 km added would not be to farfetched. All inflatable structures.

enter image description here

enter image description here

Bladder at 53km trees not included. A hole could be placed in the center.

enter image description here Not to scale.

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    $\begingroup$ This is literally zero value. 53km Vs 36000km. It would cost more in resources in every way. $\endgroup$
    – Rory Alsop
    Jan 9 '19 at 22:38

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