Balloons to Space

Tom Kalbfus · 2014-08-15 07:43:37

How do you get a balloon into space?
Simply, you inflate a balloon that is anchored to the ground and which is 100 km in radius. If you climb to the top of the balloon after it is inflated, you are in space! Bob Zubrin talked of inflatable domes on Mars, but I bet he never thought of using them in this way! An inflatable balloon also allows some horizontal distance for accelerating to orbital velocity. One needs to reach 8,000 meters per second over a distance of 100,000 meters. Average velocity of 4,000 meters per second horizontally. One would need to accelerate to 8000 meters per second over 25 seconds, this requires a horizontal acceleration rate of 320 meters per second squared, about 32 times the force of gravity, this does not include the vertical component to this acceleration. Lets look at it another way one quarter the circumference of an inflatable dome is 0.5*Pi*radius is 157,080, so an object would have to accelerate this distance along the curvature of the dome in 39 seconds at an average speed of 4000 meters per second, this requires an acceleration of 205 meters per second squared or about 20.5 times the force of gravity, about 21.5 times the force of gravity initially when lifting off the surface of the earth. acceleration = velocity^2/radius. yields a centrifugal acceleration of 640 meters per second squared, about 64 times the force of Earth's gravity. One can add the acceleration vectors together at the top of the dome to get maximum acceleration, since they are at right angles to each other, we use Pythagorean Theorem. take the square root of the sums of the squares. We have 67.2 times the force of gravity in acceleration at the top of the dome. Do you think there is any way a human can survive that over a period of 39 seconds?

There are alternatives to doing this, for instance we can accelerate segments of a linear accelerator into orbit, the pieces of which can survive 67.2 gees, put the segments together, then accelerate the human into space more gently, moving up beside the linear accelerator, the human is accelerated to orbital velocity along its length, at 50 meters per second, it would take 160 seconds to reach 8000 meters per second, requiring that the linear accelerator be 640,000 meters in length or 640 km.

What the uses do these balloons have? if you want an inflatable mountain on Venus that is 50 km high, it would require a dome of about 50 km.

Last edited by Tom Kalbfus (2014-08-15 07:52:04)

RobS · 2014-08-15 07:52:28

No, but there is also no way a balloon 100 kilometers in diameter could survive and stay in one place anyway. Such a balloon would be a wall to weather, to entire moving storm fronts, and would be pushed around and torn apart by the atmospheric forces. Even without a storm front, let us say there is a 5 mph/8 kmph breeze pushing on a balloon 100 km in diameter. How much force is that on such a huge area?

Tom Kalbfus · 2014-08-15 14:50:30

Well lets say instead of an inflated dome, we have an inflated Sphere 100 km in radius, that would mean the equator of the dome would be at an altitude of 100 km, most of the balloon would be above the atmosphere, so most of the air currents would pass underneath. If you want we could also have a 50 km radius balloon that would reach a 100 km altitude at the top, this would be a less ambitious project. You basically have to make the fabric of the balloon and then inflate it with air. At 50 km of altitude, the widest portion of the balloon, the air currents would not have much force. I think the best place to put this balloon would be on the surface of the ocean, since no one lives there.

We could place a similar balloon in the atmosphere of Venus and just let it float, put some water in the bottom and a habitat near the top, we could do the same for an Earth Balloon, except in this case the balloon would float in the ocean rather than in a carbon dioxide atmosphere. Both balloons can be used for flinging things into orbit. In fact the Venus Balloon could be used to fling Venus rocks and dirt into space, in the same manner. 50 km is the altitude of the most habitable portion of Venus, either have the balloon float in the atmosphere or rest on the surface, cooling the interior is easier with such a large volume. Probably the Venus Balloon could be built in orbit and be used as a ballute, to slow down in Venus' atmosphere and settle more gently rather than by fiery reentry such as that of an Apollo capsule

Last edited by Tom Kalbfus (2014-08-15 14:57:00)

JoshNH4H · 2014-08-16 13:13:25

Hey Tom, interesting idea. But I think you've got the shape wrong.

Think about it this way: The internal pressure of the balloon needs to be higher at every point than the surrounding atmosphere, else it will implode. The maximum amount of force that an area would be able to support would be the change in pressure between the inside and outside of the balloon multiplied by this area.

In order to maintain stability, each portion of the balloon would have to be able to support itself. Ideally this will not be through tensile strength but rather through the change in pressure over the surface of the balloon. At the same time, the balloon will have to be able to retain this change in pressure. These two criteria, put together, mean that the space balloon will be widest on the bottom and narrowest on the top, and always getting narrower.

There will also have to be some amount of overpressure, because you're going to want to be able to have stuff at the top. It would be worth considering having a slightly different gas mixture than Earth ambient, in order to increase the scale height. This, unfortunately, will mean containing significant pressure at the bottom.

Tom Kalbfus · 2014-08-16 15:25:06

Not a problem Josh, just think of the balloon as a mountain made out of air or gases. One idea I had was to have the balloon filled with hydrogen, as that is a very light gas, you can have a lot of pressure inside, but the mass of the hydrogen per unit volume would not amount to much, it would not thin out as much as the Earth's atmosphere as you increased altitude. Problem is hydrogen is flammable in Earth's atmosphere, and a 100 km hydrogen filled balloon is probably not a good idea.

The second idea is to fill the balloon with air, simply by pumping air from the outside into the balloon, you would need pressure inside the balloon to be greater than that outside of it, for the balloon itself to rise above the Earth's atmosphere. Two options for balloons is one is a inflatable dome with a radius of 100 km, the second is a ball with a radius of 50 km, both would reach an altitude of 100 km, the official definition of outer space. An air balloon has some advantages, as for example you could inhabit a portion of it and use the interior space as living space, you could hang colonies from the ceiling of the dome or sphere at the 1 bar altitude, which would be higher than the 1 bar altitude or sea level on Earth. I think either the dome or the sphere would do best resting in the surface of the ocean, that way it doesn't take up real estate, you can have a space colony hanging near the ceiling with breathable air and airlocks for those people who wish to venture into space on top of the roof. If a meteor punctures the dome, it would be the same as a space colony, the hole woul likely be small and it would take a lot of time for air to rush out, giving plenty of time to repair it, and to the a degree the dome could be designed o be self-sealing, such as a self ceiling tire.

So to sum it, it is a mountain of air under a plastic dome, a portion of the interior of which is inhabitable, so thislaunch system can also double as a space colony. A similar dome could be erected on Mars, a landing decelerator would beon the outer surface of the Dome. the pressure at the bottom of the dome would be 1 bar, at 100 km under Mars gravity there wtill would be plenty of pressure inside.

Void · 2014-08-17 10:57:37

What about terrorists, and start-up costs?

Tom Kalbfus · 2014-08-17 22:21:50

Void wrote:

What about terrorists, and start-up costs?

What about terrorists? What could a terrorist do to a 100 km radius dome full of air? Punch a hole in it? Big deal, s we patch it up later, for a balloon this size it would take a while for the air to rush out, and since its sitting on the ocean, it will only deflate, but if there are active pumps pumping air into it, it depends on whether air can be pumped into it faster than air rushes out through the hole created by the terrorist.

Start up costs would be dealt with just like any other large project, the main cost would be in creating the dome fabric and the air pump, then one just pumps air into it.

Void · 2014-08-18 09:56:42

I have decided I want to be quite supportive of this idea.
I hope I won't vandalize it, but I am going to make some further suggestions.

This seems to be an idea between mountain hopping and space elevators, and I think it has potential.

I would suggest you downsize it, so that the top of it allows a pressure of 250 mb. So that per Mr. GW Johnson, Oxygen masks could be used at the top. Along with that perhaps a deviation to the plus or minus side, that is maybe you would have a slight pressure suit, and a higher altitude and lesser pressure, but keep it at limits where the probability of survival is high in the case of a suit failure.

This alteration also provides that inside of your balloon sub balloons filled with a lifting gas could lend a great deal of support to your launch platform.

What you loose is a little altitude of launch, and also rockets then must overcome some minor atmospheric drag, but what you gain is much greater. A more human friendly environment, and a means to apply support of lift to all points of the balloon. And further, it becomes much harder for terrorists to bring the whole thing down.

This is not to say that your original dream cannot be ever worked towards, but a lesser work might be initially more attainable.

I wonder if this thing could slowly spin like a top? The point being that it would have to endure winds and waves, so why not utilize them?

If on water, then the wind spinning it, generators engaging the water outside to generate electrical power to provide resources to the human race. There are various methods, but sails unfurled into the wind, and then retracted on the other side, Wave power, by similar. Generators by turbines, or electromagnetic stimulation to a secondary coil, using the charistics of salty water.

Then, if you have water inside, you have a lagoon, do people like to live in house boats in that?

Fish farming in the lagoon.

Water cycle. If a body of water inside, then evaporation and condensation. That could cause massive trouble, but could also provide a lot of fresh water, if the design is good.

As for stirring the ocean waters, with a population peak coming up ahead (If plagues do not kill off major portions of our populations), then to promote the fertility of the seas by stirring the sea, and by the way capturing CO2.

Our cultures move in an ossilation between naturalists, and parkists. The one wants to just leave nature as it is and by default kill the humans, the other wants to apply regulation to groom reality. The groomers are coming into power at least in the Anglo-American sphere, so perhaps if a reasonable case can be made for benefit, this could be done.

The Sargasso Sea?

If you are going to have an internal lagoon, how much will the romantic and rich piggy's pay to have a houseboat in it, if it is made pleasant?

Start Up costs covered perhaps?

But I support you, whatever you choose to do with this idea, well done!

Last edited by Void (2014-08-18 10:18:33)

Tom Kalbfus · 2014-08-18 10:26:35

Void wrote:

I have decided I want to be quite supportive of this idea.
I hope I won't vandalize it, but I am going to make some further suggestions.
This seems to be an idea between mountain hopping and space elevators, and I think it has potential.
I would suggest you downsize it, so that the top of it allows a pressure of 250 mb. So that per Mr. GW Johnson, Oxygen masks could be used at the top. Along with that perhaps a deviation to the plus or minus side, that is maybe you would have a slight pressure suit, and a higher altitude and lesser pressure, but keep it at limits where the probability of survival is high in the case of a suit failure.
This alteration also provides that inside of your balloon sub balloons filled with a lifting gas could lend a great deal of support to your launch platform.
What you loose is a little altitude of launch, and also rockets then must overcome some minor atmospheric drag, but what you gain is much greater. A more human friendly environment, and a means to apply support of lift to all points of the balloon. And further, it becomes much harder for terrorists to bring the whole thing down.

You mean 250 mb on the outside I suppose, that is why you need oxygen masks on the outside. On the inside near the top, you could have a full bar of air, that would mean of course that at the bottom of the dome the air pressure inside would be 4 bar. the 250 mb altitude is higher than Mount Everest, it would still b well inside the Earth's atmosphere however, I looked it up, 250 mb is 10 km in altitude, so what were talking about here is a dome with a radius of 10 km. If resting on the ocean the pressure at the bottom inside the dome would be 4 atmospheres Antarctic glaciers are about 3 km above sea level, so if we placed such a dome on top of one of those, it would rise to an altitude of 13 km, and maybe we could have a 10 km radius habitable space underneath the dome. How would you like at 10 km radius dome on the South Pole? You could insulate the floor to keep the heat from melting the glacier underneath and grow food crops there. I think a 4 bar atmosphere of nitrogen and oxygen would be breathable.

This website seems to indicate that humans can live up to a 30 bar atmosphere
http://wiki.answers.com/Q/What_is_the_m … an_dive_to
So the dome would also be habitable for humans as well as being a launch platform, after all we don't want to waste all that real estate underneath, though the South Pole may bot be the best place to launch satellites from.

Tom Kalbfus · 2014-09-16 07:08:06

I thought this is related:
http://www.zdnet.com/blog/emergingtech/ … vator/1600
Scientists envision inflatable alternative to tethered space elevator
Summary: An inflatable free standing tower could one day carry equipment and tourists 20 kilometers above Earth, and it could be completed much sooner than a cable-based space elevator, say researchers at York University in Toronto, Canada.They envision a giant tower assembled with a series of modules made up of Kevlar-polyethylene composite tubes that would be made rigid by inflating them with a lightweight gas such as hydrogen or helium.

By Chris Jablonski for Emerging Tech | June 17, 2009 -- 23:28 GMT (16:28 PDT)

An inflatable free standing tower could one day carry equipment and tourists 20 kilometers above Earth, and it could be completed much sooner than a cable-based space elevator, say researchers at York University in Toronto, Canada.

They envision a giant tower assembled with a series of modules made up of Kevlar-polyethylene composite tubes that would be made rigid by inflating them with a lightweight gas such as hydrogen or helium. This would actively stabilize the giant tower and allow for flexibility. The elevator would support a series of platforms or pods that would launch payloads into Earth orbit.

”You can visualize it as a system of nesting segments that roll out vertically and snap into position, much like a telescoping wand,” Seth said in a news article. “You’re not constructing externally, but rather, from internally.”

To test the idea, the team built a 7-meter scale model made up of six modules (see image below).

Last edited by Tom Kalbfus (2014-09-16 07:13:39)

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#1 2014-08-15 07:43:37

Balloons to Space

#2 2014-08-15 07:52:28

Re: Balloons to Space

#3 2014-08-15 14:50:30

Re: Balloons to Space

#4 2014-08-16 13:13:25

Re: Balloons to Space

#5 2014-08-16 15:25:06

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#6 2014-08-17 10:57:37

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#7 2014-08-17 22:21:50

Re: Balloons to Space

#8 2014-08-18 09:56:42

Re: Balloons to Space

#9 2014-08-18 10:26:35

Re: Balloons to Space

#10 2014-09-16 07:08:06

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