A balloon filled with hydrogen or helium could rise almost indefinitely - if the skin is light enough, even close to the boundaries of low Earth orbit.
JP Aerospace plan to make airships that would rise to 200,000 feet - so that's 60 km.
They have the altitude record for an airship for an unmanned but manoeuvrable airship of 95,085 feet, or 29 km
JP Aerospace Airship Flies to the Edge of Space, Smashing the Existing World Altitude Record
The maximum height achieved with a balloon so far is 56 km with a NASA experiment Bu60-1
This is the highest flying balloon ever at 56 km, on the edge of space
ISAS | BALLOONS:Research on Balloons to Float Over 50km Altitude / Special Feature
JP Aerospace plan to build orbital airships that are even lighter that would launch from 200,000 feet into orbit. They would accelerate by using ion thrusters and so would no longer be using lift at that stage - after all they have to reach orbital velocity - these are huge airships that are so light they couldn't be built at ground level.
These would be truly orbital airships - and at this point would be in orbit, slowly accelerating to Mach 20 and greater, not floating, but they'd set off from a station at 200,000 feet (60 kms) and at that point would be just floating.
Though it's almost a vacuum inside the ship, still the lighter atoms of hydrogen or helium will float on the denser almost vacuum of oxygen / nitrogen outside it.
So eventually the limit is the strength of materials - how strong and how light can materials be. JP Aerospace hope to build airships that launch from ground level to 60 km and presumably that's about the limit of practicaility of an airship or balloon you can make with present day materials.
But that's only with existing materials.
We do have extraordinarily light materials we can create in small pieces and might eventually be make into large sheets.
Especially if you could make a balloon out of graphite sheets, for instance - and if you could make it impervious to helium so it can contain the gas - who knows how high a balloon could float with future materials just under its natural bouyancy?
Atom-thick carbon sheets set new strength record
LEO starts at around 160 km Low Earth orbit
JP Aerospace plan to make airships that would rise to 200,000 feet - so that's 60 km.
They have the altitude record for an airship for an unmanned but manoeuvrable airship of 95,085 feet, or 29 km
JP Aerospace Airship Flies to the Edge of Space, Smashing the Existing World Altitude Record
The maximum height achieved with a balloon so far is 56 km with a NASA experiment Bu60-1
ISAS | BALLOONS:Research on Balloons to Float Over 50km Altitude / Special Feature
JP Aerospace plan to build orbital airships that are even lighter that would launch from 200,000 feet into orbit. They would accelerate by using ion thrusters and so would no longer be using lift at that stage - after all they have to reach orbital velocity - these are huge airships that are so light they couldn't be built at ground level.
These would be truly orbital airships - and at this point would be in orbit, slowly accelerating to Mach 20 and greater, not floating, but they'd set off from a station at 200,000 feet (60 kms) and at that point would be just floating.
Though it's almost a vacuum inside the ship, still the lighter atoms of hydrogen or helium will float on the denser almost vacuum of oxygen / nitrogen outside it.
So eventually the limit is the strength of materials - how strong and how light can materials be. JP Aerospace hope to build airships that launch from ground level to 60 km and presumably that's about the limit of practicaility of an airship or balloon you can make with present day materials.
But that's only with existing materials.
We do have extraordinarily light materials we can create in small pieces and might eventually be make into large sheets.
Especially if you could make a balloon out of graphite sheets, for instance - and if you could make it impervious to helium so it can contain the gas - who knows how high a balloon could float with future materials just under its natural bouyancy?
Atom-thick carbon sheets set new strength record
LEO starts at around 160 km Low Earth orbit
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
4.8m answer views110.4k this month
Top Writer2017, 2016, and 2015
Published WriterHuffPost, Slate, and 4 moreHuffPost, Slate, Forbes, Newsweek, Business Insider, and Science 2.0