# Can something float on top of the atmosphere? [duplicate]

So this is more of a thought experiment similar to the idea of a space elevator, but bear with me...

Can we put something that "floats" on top of the atmosphere?

A few ideas

• A pressure regulating balloon

A weather balloon that doesn't pop because it self regulates it's pressure. You could even imagine something that compresses/decompresses the air to regulate both directions. Like a submarine.

• A "hard shelled" balloon

Imagine a weather balloon, but it's made of steel. Instead of some light gas (which still has weight) we take it a step further and suck out the gas completely and create a vacuum in it. It would probably crumble under 1 atm pressure, but perhaps one could suck out the gas from it when it's in space already?

• A huge "air boat"

Similar to a tin foil boat. To avoid having to deal with the problem of bursting balloons, could we just create a huge bowl. It would float like a boat floats on water, except it would float on the atmosphere. (The weight would equal it's displacement times the density of the thin atmosphere.) Would be really cool if someone had done the math on how large this would need to be... Would it cast a shadow over a quarter of the earth!?

Are there other similar ideas?

Thought experiments, obviously, but the applications would be pretty cool. Like a satellite except it wouldn't need to have a high orbital speed.

• "Air boat" has been addressed here in one way or another earlier. The atmosphere is exponential but doesn't have an edge or a surface like a liquid would, so air will pour in. A really really tall boat would take longer, but it would then be too heavy and sink. 'Hard shell" and "pressure regulating" is addressed in near space vacuum balloon and How high could a weather balloon be used on Mars without rupturing? and Maximum height for a Mars Ballon?
– uhoh
Commented Mar 21, 2019 at 4:05
• – uhoh
Commented Mar 21, 2019 at 4:19
• Thanks for the pointers! This answers my questions! Commented Mar 21, 2019 at 15:20
• Welcome to Space @aioobe! If you see something interesting feel free to ask more questions.
– uhoh
Commented Mar 21, 2019 at 15:21