Airship To Orbit

[Spacescifi]

I was thinking.... if it would be practical to create an airship to orbit SSTO?

 

 

The idea would be to rise up into the high atmosphere, and then use plasma rocketry to reach orbital velocity.

 

Possible or not?

[JoeSchmuckatelli]

Nope. 

[sevenperforce]

It has already been proposed.

http://www.jpaerospace.com/ATO/ATO.html

It has been discussed on this forum.

It will not work.

The problem is that a craft which relies upon buoyancy must, by definition, displace a volume of air greater than its own mass. In order to occupy that volume, you must have surface area. If you have surface area, you have drag, lots of it. Drag is quadratic to velocity, so if you are moving twice as fast through the air, you need four times as much thrust just to maintain velocity. Forget about acceleration. And you must stay in the air because that's the thing keeping you up.

Doesn't work at all.

[kerbiloid]

Hi, Venus.
Bye, Venus.

Spoiler

 

 

P.S.
The end of the video (with the green screen) is a NASA R&D documentary video. Probably.

[Scotius]

David Brin used something similar in his Uplift series. Giant, hollow towers rising from the equator. Transport inside was provided by enormous balloons lifting cargo and passengers to the top, where they were transferred to spaceships. All in all, it was a variation of space elevator.

[magnemoe]

12 hours ago, kerbiloid said:

Hi, Venus.
Bye, Venus.

  Reveal hidden contents

 

 

P.S.
The end of the video (with the green screen) is a NASA R&D documentary video. Probably.

An good idea, and a plausible way to get an Venus sample return mission. You would not drop humans down into the atmosphere but an manned presence in Venus orbit would be nice for shorter signal lag but would obviously increase the mission scope, say two Starship.
Drop an airship down, have it drop sample return probes down to the surface, here you have limited time before you have to release an balloon who the airship sends out an capture drone who grabs the payload and return it, it will then be moved into the accent rocket. 
Then done, climb and drop the rocket so that it can meet up with the manned ship who recover the sample return package and goes back to earth. 

[farmerben]

I've wondered about de-orbiting an airship.  The whole problem is with overheating.  I don't think we know conclusively if it would work.  

[kerbiloid]

Delta-V and docking in the windy stratosphere to the wiggling lightweight balloon make this enterprise... insanely hard and risky.

Besides the fact that the chemical reactions (and thus equilibrium) at 20°C and 1 atm are rather different from 480°C and 90 atm.

So, to the moment of delivery, the samples will be not much similar to the stones on surface.

Just now, farmerben said:

I've wondered about de-orbiting an airship.  The whole problem is with overheating.  I don't think we know conclusively if it would work.  

https://en.wikipedia.org/wiki/Vega_program

Spoiler

 

Spoiler

 

 

[sevenperforce]

2 hours ago, farmerben said:

I've wondered about de-orbiting an airship.  The whole problem is with overheating.  I don't think we know conclusively if it would work.  

If it’s light enough, large enough, and stiff enough, it will deorbit with just fine with minimal heat shielding required.

[benzman]

19 hours ago, Spacescifi said:

I was thinking.... if it would be practical to create an airship to orbit SSTO?

 

 

The idea would be to rise up into the high atmosphere, and then use plasma rocketry to reach orbital velocity.

 

Possible or not?

A balloon in orbit would go POP.

[sevenperforce]

2 minutes ago, benzman said:

A balloon in orbit would go POP.

Balloons have been inflated in orbit before; you just have to get the pressure right.

A balloon pressurized to 3 atm at sea level is under the same stress as a balloon pressurized to 2 atm in a vacuum. 

[Zacspace]

54 minutes ago, sevenperforce said:

Balloons have been inflated in orbit before; you just have to get the pressure right.

A balloon pressurized to 3 atm at sea level is under the same stress as a balloon pressurized to 2 atm in a vacuum. 

You can also just have a balloon filled with vacuum. It might seem counterintuitive, but vacuum is lighter than helium/hydrogen since it's literally/ideally nothing. It's theoretically more efficient than a gas filled balloon for lifting. I'm pretty sure such a thing has seen real-world development despite the obvious challenges.

Maybe in some sci-fi world, a vacuum airship could be made that uses magnetic or static fields in place of pressurized gas to rigid-ize the hull without needing to rely on a heavy internal structure.

Edited July 6, 2022 by Zacspace
or

[magnemoe]

4 hours ago, kerbiloid said:

Delta-V and docking in the windy stratosphere to the wiggling lightweight balloon make this enterprise... insanely hard and risky.

Besides the fact that the chemical reactions (and thus equilibrium) at 20°C and 1 atm are rather different from 480°C and 90 atm.

So, to the moment of delivery, the samples will be not much similar to the stones on surface.

Yes obvious very hard and idiotic expensive, but its an plausible way for an Venus sample return, again you could contain the atmosphere with the sample but not the temperature or pressure, not something you would bother doing until you had sample return from most other places. 

[sevenperforce]

50 minutes ago, Zacspace said:

You can also just have a balloon filled with vacuum. It might seem counterintuitive, but vacuum is lighter than helium/hydrogen since it's literally/ideally nothing. It's theoretically more efficient than a gas filled balloon for lifting. I'm pretty sure such a thing has seen real-world development despite the obvious challenges.

There's been a great deal of discussion of this concept.

https://en.wikipedia.org/wiki/Vacuum_airship

You can get to the required compressive strengths needed to have a spherical vacuum balloon using aluminum alloys, but you'd need internal reinforcement to prevent buckling.

51 minutes ago, Zacspace said:

Maybe in some sci-fi world, a vacuum airship could be made that uses magnetic or static fields in place of pressurized gas to rigid-ize the hull without needing to rely on a heavy internal structure.

Or perhaps you could have some sort of rotating  (un)pressure vessel? The rotation could be set up to provide auxiliary lift AND supply centrifugal force to prevent buckling, at least in the plane normal to the axis of rotation.

[magnemoe]

10 hours ago, Scotius said:

David Brin used something similar in his Uplift series. Giant, hollow towers rising from the equator. Transport inside was provided by enormous balloons lifting cargo and passengers to the top, where they were transferred to spaceships. All in all, it was a variation of space elevator.

If you have an tower you don't need an balloon as you can use an lift, way smaller for the cargo capacity.
Now orbit is not high its fast, the idea of an supersonic airship is kind of weird as in design it then go hypersonic  
 

[mikegarrison]

1 hour ago, Zacspace said:

You can also just have a balloon filled with vacuum. It might seem counterintuitive, but vacuum is lighter than helium/hydrogen since it's literally/ideally nothing. It's theoretically more efficient than a gas filled balloon for lifting. I'm pretty sure such a thing has seen real-world development despite the obvious challenges.

Maybe in some sci-fi world, a vacuum airship could be made that uses magnetic or static fields in place of pressurized gas to rigid-ize the hull without needing to rely on a heavy internal structure.

I recall a book I read where the main characters built a metal chamber with a vacuum inside, and supposedly it displaced enough air that it was buoyant. I suspect that in reality this would be nearly impossible, because the compressive strength to resist 1 atm of pressure would require a heavy structure. Hot air and light-gas balloons work because they can pretty closely match the pressure with the outside atmosphere.

[SunlitZelkova]

Although not exactly the OP’s proposal, I wonder if using an airship for air-launching a rocket has ever been considered (Virgin Orbit style).

Pros: It would look and be cool, maybe larger payload?

Cons: Won’t fly as high, can’t do the pitch up maneuver an aircraft can, and the rocket will start much slower.

[Spacescifi]

1 hour ago, SunlitZelkova said:

Although not exactly the OP’s proposal, I wonder if using an airship for air-launching a rocket has ever been considered (Virgin Orbit style).

Pros: It would look and be cool, maybe larger payload?

Cons: Won’t fly as high, can’t do the pitch up maneuver an aircraft can, and the rocket will start much slower.

 

That will be a multi-kilometer wide balloon.

You really won't need to pitch up though.

 

Make a massive torus (donut shaped) balloon and have the spacecraft and booster hanging down the hole.

 

Then once at altitude release and boost away.

 

Would be slow but effective.

Edited July 7, 2022 by Spacescifi

[magnemoe]

3 hours ago, sevenperforce said:

There's been a great deal of discussion of this concept.

https://en.wikipedia.org/wiki/Vacuum_airship

You can get to the required compressive strengths needed to have a spherical vacuum balloon using aluminum alloys, but you'd need internal reinforcement to prevent buckling.

Or perhaps you could have some sort of rotating  (un)pressure vessel? The rotation could be set up to provide auxiliary lift AND supply centrifugal force to prevent buckling, at least in the plane normal to the axis of rotation.

An vacuum airship would work better in the stratosphere as you only needed to handle 0.1 bar or less. 
It would still need to be huge and drag would make it slow. and you would have an leak issue and its easier to replace hydrogen than remove air from an huge vacuum. 

[Spacescifi]

9 minutes ago, magnemoe said:

An vacuum airship would work better in the stratosphere as you only needed to handle 0.1 bar or less. 
It would still need to be huge and drag would make it slow. and you would have an leak issue and its easier to replace hydrogen than remove air from an huge vacuum. 

 

I just had a crazy idea that could work!

 

Use spin launch to yeet a spacecraft up so that it is caught in adhesive netting in the 'hole' of a massive torus balloon, which is held in place by long tethers on the ground.

 

Then boost the rocket until it reaches another net hole of another higher balloon.

 

Allow the balloon to transfer gas as a fuel source so that it begins to descend, then release the rocket and boost and rinse and repeat with another balloon until you cannot.

 

Could possibly SSTO with this with the rocket.

Edited July 7, 2022 by Spacescifi

[Shpaget]

If the balloon can carry the spacecraft, the you don't need the convoluted throw and catch rinse and repeat Rube Goldberg contraption. Just winch it.

Also, nobody cares about SSTO. It has been explained over and over. Seriously.

Edited July 7, 2022 by Shpaget

[kerbiloid]

If SS/SH landing accuracy is as good as they hope, screw the tower. Just land the second stage on top of the landed first one and lock.

Keep doing this with more stages.

Then you can use SSTO, TSTO, TSTO, FSTO, FSTO, SSTO, SSTO, ESTO, NSTO, TSTO, ESTO, TSTO, TSTO, etc. same easy as SSTO.

Spoiler

Single Stage To Orbit, Two STO, Three STO, Four STO, Five STO,  Six STO, Seven STO, Eight STO, Nine STO, Ten STO, Eleven STO, Twelve STO, Thirteen STO, etc.

[Gargamel]

1 hour ago, Spacescifi said:

 

I just had a crazy idea that could work!

 

Use spin launch to yeet a spacecraft up so that it is caught in adhesive netting in the 'hole' of a massive torus balloon, which is held in place by long tethers on the ground.

 

Then boost the rocket until it reaches another net hole of another higher balloon.

 

Allow the balloon to transfer gas as a fuel source so that it begins to descend, then release the rocket and boost and rinse and repeat with another balloon until you cannot.

 

Could possibly SSTO with this with the rocket.

This is called a RGTO.  

Rube Goldberg to Orbit. 
 

Not saying it won’t work, just seems overly complicated.  

[mikegarrison]

5 hours ago, SunlitZelkova said:

Although not exactly the OP’s proposal, I wonder if using an airship for air-launching a rocket has ever been considered (Virgin Orbit style).

Yes, it has been considered.

A quick summary:

Edited July 7, 2022 by mikegarrison

[CBase]

Are there any serious numbers out there how much mass you actually save from any high altitude launch (20km+) ?