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Can a vacuum balloon be built with current material technologies? Answered

A balloon's bouyancy (lifting force) is a function of how much air it displaces. Today's balloons use hot air, hydrogen, helium and other lighter than air gases for lift. In 1670 Franceso de Lana, an italian monk, proposed the use of a vacuum. One major problem is how to make the structure light enough to support a vacuum without collapsing in on itself due to the outside pressure.



Best Answer 5 years ago

Hears a link to a lot of the technical aspects of what you would need. I don't know if the math works because I haven't seen anyone with a vacuum balloon but you might want to read it all the through a couple of times.http://aoi.com.au/Originals/VacuumBalloon.pdf

Yes, it can be built. Me and my team built a prototype back in 2008 in India. I was in my sophomore year and did not do much of documentation to prove it to you guys (if you are skeptical)

Thank you, I wish you had taken pictures, but is nice to know some people have done it before.


5 months ago

If you try to make a sphere which is the most efficient object for this task and put a vacuum inside of it with the volume of a liter you would need to use less than 1.28 grams of material to make it float. This would be very difficult at sea level but it would be less difficult on Mount Everest and the even easier on the edge of our atmosphere. Anyways the direction I'm going with this is it could be easier to create a vacuum inside a bubble if you have layers of bubbles around it with gradually lower pressure. A special valve would need to be made to remove air from all containers at once separately.


The simple answer is "no". Using modern materials, a balloon-shaped object containing a vacuum would be too heavy to be lifted.

I kinda agree... but how about application of vacuum chamber in submarine as a ballast tank? would it give faster rate of submarine surfacing? do anyone know ?

You can do the maths yourself - Compare the mass of a submarine with air-filled ballast tanks to the mass of a submarine with vacuum-filled ballast tanks.

it has been suggested that plasma fields or magnetically held metal can be used. but plasma is complicated and relies on enormous amounts of electricity to contain them, and the magnet thing is complicated and has never been attempted

might piso-electricity be manipulated to help maintain an absolutely perfect sphere. if the molecules in the containment shell could be so arranged that they remained stable even under the most extreme compression, then provided you went large enough (M40, glurth) it aught to be possible and needless to say the implications are potentially huge.

I think there may be an underlying problem with the physics of this "vacuum" balloon theory. Now I don't profess to be an expert here and anyone is free to bring better evidence here for a more complete picture of this problem. Balloons float because the gas inside weighs less than the surrounding atmosphere, yet can occupy an equal volume of space.
I'm trying to remember back to physics class but I believe that all gasses will exert equal pressures if the numbers of molecules are equal as well with the same temperature (this temperature difference is what makes a hot air balloon work using just air). A trillion hydrogen molecules in a balloon pushes out with the same force as one with a trillion nitrogen molecules. Now this "force" is the key. Even though gasses have the same force, they do not have the same weight. Hydrogen or helium weigh less than most other gasses. Since these gasses in a balloon will push against the outside atmosphere equally, yet weigh less, you now have something that will float. Balloons (filled with light gasses) work because they are flexible and allow the internal gas to exert it's pressure and force on the outside atmosphere.
So now let's put a vacuum in a balloon. The first problem we have is that the outside pressure is so great that we can not hold a volume that can displace the atmosphere (see, there is no internal force here). Now, let's imagine we have something very strong and light that can hold our vacuum. We have something that occupies a volume, but there is no force here pushing out against the atmosphere (since "nothing" or a vacuum can't exert a force). This vacuum balloon simply has the weight of the balloon material itself, which is likely going to have some weight and be more dense than the surrounding air and it will not float.
So that's my take on this. Even if we could make a vacuum balloon, I'm not sure it would work, or float. I'm basing a lot of this issue on how a gas exerts a pressure on the outside atmosphere (combined with volumes and weights) to enable it to float. I hope this helps and lets others confirm or update all the factors that go into this issue.

As you have said, "Since these gasses in a balloon will push against the outside atmosphere equally, yet weigh less, you now have something that will float. Balloons (filled with light gasses) work because they are flexible and allow the internal gas to exert it's pressure and force on the outside atmosphere."

So what you actually need is a stable structure that weights less than the volume of atmosphere displaced. If the overall mass of the balloon (air+structure+load) is less than the mass of the volume of atmosphere displaced, we have buoyancy. A vacum ballon will have far less mass that a same size hydrogen balloon (as the hydrogen balloon has less mass that a hot air one) so it will have much more buoyancy than it.

The only problem is if can be created a structure light enough and solid enough to withstand the external pressure. If this can be done, I don't know, but the idea in theory is solid.


5 years ago

The issue is that the structure is fighting the pressure differential between SEA LEVEL atmosphere outside and the vacuum within (causes implosive forces).

The solution is twofold. First... build it LARGE. This makes for the greatest amount of interior space as opposed to the structure that contains it. ALSO, you'd need to initially fill it with helium or hydrogen. Once the ship has risen as high as it will go under 'lifting gas', you can then SLOWLY pump out that helium/hydrogen until a vacuum or near vacuum is achieved.

You would continue to pump out your original gas load of helium or hydrogen such that the structure never sees forces capable of crushing it. It only sees enough forces as are required to keep the structure bouyant.

Picture a nuclear-powered zeppelin like structure... much larger than an aircraft carrier... floating along at 150,000 feet... able to stay up almost indefinitely.

If the nuclear power can be used not just for the pumps, but to capture hydrogen from the moisture in the atmosphere, then this ship can effectively add hydrogen to descend as needed.

PS - NASA has helium balloons that soar to 120,000 feet with a 1 ton instrument payload. Not sure if the difference between hydrogen, helium and vacuum makes it worth the extra effort.

Perhaps the goal should be to achieve the best of both worlds. Design the vacuum balloon portion to operate at an altitude where thermal balloons won't. At those altitudes crushing force won't be near as big a problem (I'm guessing). In a way trying to make it work from sea level up would be like trying to make a pool float that could survive being under a mile of seawater.

We live in a dynamic environment, and at the pressure range we typically live at, barring the development of cheap super materials, thermal aircraft are just more suited. That said, I don't see any reason why a staged construction wouldn't be possible. Something that converts from thermal to vacuum at a certain altitude, much like how the F14 changes geometry for different speeds.

One way would just be a folding craft, or maybe a launching craft kind of design. One stage carries the second stage which then launches. It could parachute back down while the first stage could simply land.

This might also be done more simply by designing the shell to accept both vacuum and heated air. Also pumping out air and heating it can both be accomplished electrically. This opens the door for a solar powered craft. Something that would climb through the lower atmosphere like a weather balloon and then gradually pump out the hot air as the pressure drops.

However, I don't know the math. It may be that no such bootstrapping is possible on the grounds that the gains of vacuum are too far away from a thermal craft's maximum altitude. Or put differently it may be that even at max hot air altitude any currently possible vacuum craft would still be too fragile under pressure at that altitude.

Bottom line: The real advantage of vacuum craft is the theoretical ability to float to the very top of the atmosphere; trying to build a pure vacuum craft may be a waste.

Step one in my opinion should be to make a craft that reaches the thermal ceiling and then go from there. According to wiki: On November 26, 2005, Vijaypat Singhania set the world altitude record for highest hot air balloon flight, reaching 21,290 m (69,850 ft). That's 13.2 miles, that's well into the stratosphere, and that was carrying a considerable load. So maybe we should be asking if a vacuum balloon possible at 13.2 miles altitude.

Answer with a question, right?  That's science. :-)
Question: what's the advantage?
What does a cc of hydrogen weigh at sea-level versus a cc of vacuum?
(hint: vacuum weighs zero)
So how does that scale to a cubic meter?  Cubic kilometer?
What's the difference in lift?  Sea-level might not be a practical application but higher up those collapsing forces drop.  How's that change things?
Heck you can hold up anything with a strong enough magnetic field but you'd be better off just building a rail gun if you had all that juice.
Could you ever get enough lift to create a super-high-altitude deck for launching payloads into low-Earth orbit?  Might even be able to do that with hydrogen.
Hey, how about hydrogen/aluminum foam created in a zero-G environment.
Maybe even on the moon.  Lots of H and Al there.
Hydrogen/titanium?  Hydrogen/carbon?
What ever it is, if you make it please promise to give me a ride on it!


8 years ago

A more apt answer might be this: It isnt worth it In effect what you will be doing is getting rid of the weight of the hydrogen and replacing that weight with the material you use to hold out the atmosphere. Plus of course one tiny failure in that system would be catastrophic where a failure in a gas balloon isnt.


9 years ago

The larger you make the balloon, or polyhedron, the greater your displacement to surface area ratio. This means you can make you walls, columns, whatever, thicker and heavier as a percent of it's size. Volume is the third power(cubed) of the radius. Surface area is the second power(squared) of the radius.

You may wish to look at our US patent application 20070001053 (11/517915) (at http://portal.uspto.gov/external/portal/pair enter the verification code and then 11/517915). We propose an evacuated sandwich spherical shell with two thin face sheets and a light core between them. Finite element analysis confirmed that the structure using commercially available materials (e.g., boron carbide face sheets and aluminum honeycomb core) can be light enough to float in air and strong enough to withstand the atmospheric pressure with decent safety factors for strength, buckling, and intracell buckling. Actual manufacturing, while definitely possible, is not easy.

I talked about this with a friend of mine back on Turkey Day. He's a PhD student majoring in Physics at U. W. And like Putzer, my friend likes Buckyballs. Apparently, as the construction material gets heavier, the size must increase to overcome the weight. So use aluminum for minimal weight and maximum stiffness. Skin the thing in whatever you like, and paint it black to absorb thermal energy from the sun. It will lift itself. For further research, take a look at Buckminster Fuller, Buckyballs, Dimaxian House, and geodesic dome.

Maybe if it was made of a light weight, yet rigid enough plastic that would not succumb to atmospheric pressure.


9 years ago

Perhaps buckyballs?