NationStates Jolt Archive

During a recent time-wasting session with Wikipedia, I came across the Orbital Airship (http://en.wikipedia.org/wiki/Orbital_airship) article, which piqued my interest enough to read several other related topics, including Non-rocket Spacelaunch (http://en.wikipedia.org/wiki/Non-rocket_spacelaunch) (which I encourage you to check out, if for no other reason than to giggle over some of the ridiculous ideas, such as the Space Gun and the Slingatron).

After my initial reaction, it sounds almost plausible. To hell with carbon nanotubes; why not use helium balloons to build a space elevator? And why stop there; wouldn't it be possible to build entire structures out of lightweight and helium-filled materials? Say (bear with me), a aluminum skyscraper filled with helium (or attached to a helium balloon)? Could there be an entire, previously unexplored school of architecture that takes advantage of the buoyant force on lighter-than-air gases?

I realize I know next to nothing about architecture or the physics of the situation ... but anyone who is, care to weigh in? Am I crazy? Or could it work?

Yes, none of that would work.

http://celebritynews.yuddy.com/wp-content/uploads/2007/10/kari%20byron%20with%20her%20balloons.jpg

the first problem i see is that you need a lot of helium to lift even just kari byron

the first problem i see is that you need a lot of helium to lift even just kari byron

The ratio would need to be huge, but not necessarily enough to make a structure airborne. Just enough to reduce the weight of a structure so that it wouldn't collapse if it had a foundation that wasn't concrete (or whatever is currently used).

Non-rocket spacelaunch is one of NASA's goals, as I recall. Granted, that was according to Popular Science a year or so ago and may have changed since, but the development of a space-going vehicle that takes off without a separate propulsion system is definitely a goal that some engineers have seriously considered. That probably won't mean baloons or a 'space elevator,' but it's something.

It sounds like super-great steampunk. And think of the potential for explosions. Definitely worth it. Let's green light this project.

Non-rocket spacelaunch is one of NASA's goals, as I recall. Granted, that was according to Popular Science a year or so ago and may have changed since, but the development of a space-going vehicle that takes off without a separate propulsion system is definitely a goal that some engineers have seriously considered. That probably won't mean baloons or a 'space elevator,' but it's something.

nasa spends a good chunk of money on the research for non rocket space launch.

If rail gun technology is perfected, then a non-rocket launch might be possible. Of course there would be the matter of G-force on the crew but by then they should come up with a solution for that.

nasa spends a good chunk of money on the research for non rocket space launch.

That's a good thing, I think. My memory had it that a portion of the $5b that Bush sent NASA around '06 was specifically dedicated to that end - we're going to need a more efficient system in the long run, in any event.

If rail gun technology is perfected, then a non-rocket launch might be possible. Of course there would be the matter of G-force on the crew but by then they should come up with a solution for that.

they have suits. and supports. the suits keep the crew from passing out by keeping blood in the brain. and the supports keep the bones from collapsing.

If rail gun technology is perfected, then a non-rocket launch might be possible. Of course there would be the matter of G-force on the crew but by then they should come up with a solution for that.

they have suits. and supports. the suits keep the crew from passing out by keeping blood in the brain. and the supports keep the bones from collapsing.

As Gerald Bull has already proven with the HARP program, superguns "can" launch a projectile into orbit (he specialized in artillery guns, not rail guns but they both serve the same objective). That's big "can" launch a projectile into orbit however. People are not a viable projectile in these instances. With project HARP, the 180 kg projectile had an intitial velocity of 3600 m/s as it was fired. In other words, 0 - 12960 km/h in a near instant. That only took it 180 km in altitude. I'm not an engineer nor a biologist by any means but I do know that people were not designed to be accelerated to 11.2 km/s (escape velocity) in less than a second.

That doesn't mean superguns don't have a use in future space launches however. When it comes to launching payloads of non-persons and other objects that can survive and are designed to cope with the forces involved, a space gun launch may prove to be a cheaper (and greener?) alternative than the standard issue chemical rocket.

http://celebritynews.yuddy.com/wp-content/uploads/2007/10/kari%20byron%20with%20her%20balloons.jpg

the first problem i see is that you need a lot of helium to lift even just kari byron
*drools over teh hotness*

the first problem i see is that you need a lot of helium to lift even just kari byronWhen i "lift" Kari Byron, you'd better believe it isn't gonna be with helium.
*nods emphatically*
Right, Dinaverg?

*drools over teh hotness*Again substantiating your Goddess status.
:hail:

From the article.


They also point out that, unlike getting to space on a rocket, if something goes wrong on an airship, nothing bad will happen to you or your payload.

Does anyone think of this?

http://ecotality.com/life/wp-content/uploads/2007/11/hindenburg.gif

From the article.



Does anyone think of this?

http://ecotality.com/life/wp-content/uploads/2007/11/hindenburg.gif

Helium, unlike hydrogen, isn't flammable. Sorry.

Beat me to the punch on that last on, Callisdrun. :(

I've heard that the US is looking into Lighter Than Air surveillance and reconaissance tools. I assume that they would work much in the way that weather balloons do. I've also heard that they could be adapted in the future as weapons systems, but I would believe this kind of tool would be outpaced by satellite coverage/weapons/frickin' lasers, so the gains of this kind of vehicle would be interesting to research.

When i "lift" Kari Byron, you'd better believe it isn't gonna be with helium.
*nods emphatically*
Right, Dinaverg?

You rang?

Helium, unlike hydrogen, isn't flammable. Sorry.

A Secrets of the Dead episode on the Hindenburg theorized that while the hydrogen certainly made things worse it wasn't the actual cause of the fire:

http://www.pbs.org/wnet/secrets/html/e3-chemistry.html

A Secrets of the Dead episode on the Hindenburg theorized that while the hydrogen certainly made things worse it wasn't the actual cause of the fire:

http://www.pbs.org/wnet/secrets/html/e3-chemistry.html

The Mythbusters "busted" that one recently, if the Mythbusters are an authority. :tongue:

The Mythbusters "busted" that one recently, if the Mythbusters are an authority. :tongue:

thus we return full circle to kari byron.

From the article.



Does anyone think of this?

http://ecotality.com/life/wp-content/uploads/2007/11/hindenburg.gif

what does the burning of a hydrogen-filled zeppelin have to do with helium filled balloons (or what-ever)?


EDIT: okay, I was beaten to the punch, but still...


to make up for it, here is a higher res pic of the scrumptious Kari
http://i236.photobucket.com/albums/ff315/Sarothai/Kari_Byron_with_balloonssized.jpg

The Mythbusters "busted" that one recently, if the Mythbusters are an authority. :tongue:

The Myth that was busted apparently falls on the premise that hydrogen had nothing to do with the destruction of the Hindenburgh. Secrets of the Dead merely theorized that the paint compound and the lightning was the source of the ignition, in contrast to media release that blamed it entirely on spontaneous combustion of the hydrogen back in the days of the tragedy.

The static-charged paint compound ignited, and when the fire got big enough hydrogen did the rest.

Helium, unlike hydrogen, isn't flammable. Sorry.

Nah, I know it's not flammable. But a critical loss of buoyant gas is not likely to end well. And in fiction and real life, saying "nothing bad will happen" challenges both Murphy and fate. You don't want to invoke them.

After my initial reaction, it sounds almost plausible. To hell with carbon nanotubes; why not use helium balloons to build a space elevator?
Because it won't work. A space elevator has to be 40,000 km long; balloons can at best work up to 20 km. That's 0.5%.

And why stop there; wouldn't it be possible to build entire structures out of lightweight and helium-filled materials? Say (bear with me), a aluminum skyscraper filled with helium (or attached to a helium balloon)?
And inhabited by Slylandro. Surely it is.

As for humans, it all comes down to a steel column being much cheaper than a helium balloon, while supporting a lot more.


If rail gun technology is perfected, then a non-rocket launch might be possible. Of course there would be the matter of G-force on the crew but by then they should come up with a solution for that.
Just build a 250km long and no less than 30km high railgun, and you'll be all set. Maybe.

At reasonable size, the accelerations are acceptable only for shipping bulk materials, food, water, etc., but not actual spacecraft.

Nah, I know it's not flammable. But a critical loss of buoyant gas is not likely to end well. And in fiction and real life, saying "nothing bad will happen" challenges both Murphy and fate. You don't want to invoke them.

A picture of a popped balloon would have been more effective at illustrating that point.

I imagine a lot of thought would have to go into that aspect of the idea. Since it would be a big problem, should it happen.

Also, for some reason this thread is making me think of "99 Red Balloons."

Because it won't work. A space elevator has to be 40,000 km long; balloons can at best work up to 20 km. That's 0.5%.
The 40 Mm length is not really requirement, unless you want to be able to push payload off with no additional acceleration or if the structure isn't rigid...in which case 40 Mm is only half the story. Getting a structure even up to 100-150 km has distinct advantages to a landbased solution, for example air pressure is nearly 0 enabling high acceleration launches.

Also, the record height for a balloon is around 50 klicks so conceivably up to that height helium or hydrogen could be used the help support the structure.

Overall I have to agree with your assessment, though, that it's still pretty futile effort: Balloons are *no* solution to space travel. :)
And inhabited by Slylandro. Surely it is.
:fluffle:

Just build a 250km long and no less than 30km high railgun, and you'll be all set. Maybe.
One word: Friction.

At reasonable size, the accelerations are acceptable only for shipping bulk materials, food, water, etc., but not actual spacecraft.

Well, a ~1300 kilometer (http://www.google.com/search?q=%2811.2+km%2Fs%29%5E2+%2F+%282%2A+%285%2A9.81m%2F%28s%5E2%29%29%29) accelarator rail would be enough to reach escape velocity if you accept 5g acceleration.

Whether that's reasonable depends on your take on reasonable :D

The 40 Mm length is not really requirement, unless you want to be able to push payload off with no additional acceleration or if the structure isn't rigid...in which case 40 Mm is only half the story.
Actually 40,000 km is enough, the counterweight part doesn't have to be as long, arm can be traded for mass - so it's 36,500 to the GSO and 1/10 that from there to counterweight.

Space elevator doesn't solve all of the issues even then, however. It doesn't allow to launch to LEO or MEO without extra rocket stage (a major stage), and even if launching to GEO, the payload has to be sent into the proper orbit - an elevator only covers the equator.

But the main issue is that it's insanely uneconomical; I did some calculations, assuming the best in nanotubes even theoretically expected possible to produce so far, and it shows the idea "We just need to build a thin one, then it will build itself up!" to be flawed: the elevator would need 20 years to lift enough material for a copy of itself. That's with assumptions so perfect they won't be achieved in Utopia itself.
And invested in proper economy at even just 5% per year - in twenty years you'd get 165% gain, not 100%, and these 100% are assuming you wouldn't have the old elevator worn out by micrometeoroids and the nanotubes themselves were free, which they are far from.

To work it would take materials even stronger than nanotubes as we know them, or absolutely perfect nanotubes. And just for the measure, Kevlar is 40 years old, but theoretical (perfect) Kevlar is still 8-10 times stronger than the practical material.


Getting a structure even up to 100-150 km has distinct advantages to a landbased solution, for example air pressure is nearly 0 enabling high acceleration launches.
How does air pressure matter in acceleration? It has negligible effect on rocket engines.

If you mean high initial velocity launches, like with a railgun, coilgun, or a cannon, then yes, it would take burning in the atmosphere out of the equation, but the entire point of these cannon launch systems is being built on the ground, where they are cheap to build.


Also, the record height for a balloon is around 50 klicks so conceivably up to that height helium or hydrogen could be used the help support the structure.
Imagine the size of the balloon required.
They only reach such heights due to being made extremely light, nothing but micrometer-thin film. At 50km, air density is so low, that the 60,000 m^3 balloon had to weigh just 34kg. For comparison, a low-altitude 60,000 m^3 balloon can lift 70 tonnes, over 2,000 times more.


Well, a ~1300 kilometer (http://www.google.com/search?q=%2811.2+km%2Fs%29%5E2+%2F+%282%2A+%285%2A9.81m%2F%28s%5E2%29%29%29) accelarator rail would be enough to reach escape velocity if you accept 5g acceleration.
Whether that's reasonable depends on your take on reasonable :D
The size is clearly not reasonable; that's the issue.
To minimize drag (which is destructive), the launch has to be close to vertical, and the release point (where the vacuum seal is) has to be as high as possible. But, unfortunately, the possible heights are too short, and accelerating the payload horizontally first would cause too much angular acceleration when turning.

Actually 40,000 km is enough, the counterweight part doesn't have to be as long, arm can be traded for mass - so it's 36,500 to the GSO and 1/10 that from there to counterweight.
Right you are.
How does air pressure matter in acceleration? It has negligible effect on rocket engines.1 word: Friction. :cool:

You could save up to 20% of energy in LEO launch, according to Wiki's page on delta-v budget anyways.
The size is clearly not reasonable; that's the issue.
To minimize drag (which is destructive), the launch has to be close to vertical, and the release point (where the vacuum seal is) has to be as high as possible. But, unfortunately, the possible heights are too short, and accelerating the payload horizontally first...
I'd gather the structure would be a horizontal semi-vacuum tunnel, which might open to a height of 10-15 kilometers to an angle of 15-30 or so degrees.

The longest current rock tunnel is 120 kilometers so it wouldn't really be that megalomanic leap compared to a spacelift. For some perspective the main loop of LHC tunnel is 27 kilometers long.

The benefits of an accelerator launcher are:
- Completely constructable with current technology
- Relatively cheap cargo hauler...
- ...which could later be expanded to people carrier.
- Any place on Earth qualifies as a building site as long as the area has sufficient tectonic stability. While equatorial positioning & alignment are beneficial they aren't necessities.
- Can theoretically be used to launch to anywhere on the system

You could for example start off with a 60 kilometer cargo rail which could be used to haul payloads in order of tonnes into low earth orbit. The only real question is, how to cheaply accomplish sustained power output of 5-10 gigawatts or so for around 20 seconds. :)
...would cause too much angular acceleration when turning.
The acceleration caused by curvature would be tricky especially for manned launch. A 30 kilometer curvature to 15 degree angle and velocity of 9 km/s (LEO) would cause around 11g peak acceleration, uncomfortable for sure but not deadly especially as it wouldn't last that long.

Lighter than air architecture won't work.

let us look at the example of the aluminum skyscraper held up by helium balloons. Assuming that the balloons don't pop (this is a huge assumption), the only way you would reduce the structural load is by reducing the weight supported by the compression members. So, it would not reduce, for example, the lateral load on the building caused by the wind. Now, a lighter-than-air building would have to be additionally reinforced to counteract this. With steel probably.

Additionally, the helium would only replace the weight of the structural members, not any other part of the building. Most of the time, this is less than half of the weight of the structure.

You couldn't make the floors out of the 'balloons' either, as they wouldn't resist the bending.

I have seen these in action, mind you, as single floor buildings in mild environments. They are useful for arenas and such, as the roof and exterior walls are just one big inflated tunnel. They still require a concrete foundation to prevent the whole thing from blowing away. And it's a bitch to bring in plumbing through the 'exterior wall'.

This would essentially require a complete and total violation of the laws of physics.

And if we're doing that, we might as well add in super airships of doom.

Helium, unlike hydrogen, isn't flammable. Sorry.
Well, what's the freakin' point then? Where's the challenge?

During a recent time-wasting session with Wikipedia, I came across the Orbital Airship (http://en.wikipedia.org/wiki/Orbital_airship) article, which piqued my interest enough to read several other related topics, including Non-rocket Spacelaunch (http://en.wikipedia.org/wiki/Non-rocket_spacelaunch) (which I encourage you to check out, if for no other reason than to giggle over some of the ridiculous ideas, such as the Space Gun and the Slingatron).

After my initial reaction, it sounds almost plausible. To hell with carbon nanotubes; why not use helium balloons to build a space elevator? And why stop there; wouldn't it be possible to build entire structures out of lightweight and helium-filled materials? Say (bear with me), a aluminum skyscraper filled with helium (or attached to a helium balloon)? Could there be an entire, previously unexplored school of architecture that takes advantage of the buoyant force on lighter-than-air gases?

I realize I know next to nothing about architecture or the physics of the situation ... but anyone who is, care to weigh in? Am I crazy? Or could it work?

They also point out that, unlike getting to space on a rocket, if something goes wrong on an airship, nothing bad will happen to you or your payload.
http://en.wikipedia.org/wiki/Orbital_airship

Hmmmmmm.

1 word: Friction. :cool:
You could save up to 20% of energy in LEO launch, according to Wiki's page on delta-v budget anyways.
Well, that's not even serious. 20% isn't going to make the weather - and, considering the effort of maintaining and using this "balloon elevator", it'll end up costing more.

Furthermore, if we have balloons, there's no need for the elevator, they're elevators themselves.
So, a slightly more reasonable option would be to lift the first stage using a non-rigid balloon of sorts. It could provide altitude for a semi-aircraft launch system, such as one using first-stage high speed, high altitude, possibly hydrogen fueled plane with a second-stage rocket. Such an aircraft would have trouble taking off on its own, due to drag and unsuitable engines, but launched from altitude, it could dive to gain some speed, and then get flying.

However, one word that comes to my mind (as an engineer) is "fiddly". Space Shuttle program is an amazing piece of technology, but all we've gained from it is learning that the "KISS" principle holds in space too.


I'd gather the structure would be a horizontal semi-vacuum tunnel, which might open to a height of 10-15 kilometers to an angle of 15-30 or so degrees.
15 degrees is hardly a suitable angle. There we get too much flight through the atmosphere, and even at 15km, I doubt shielding will hold long enough. Again, the difficulty of achieving 10-15km... Most mountains are only a couple km high, and the terrain around higher ones is difficult to work with.


You could for example start off with a 60 kilometer cargo rail which could be used to haul payloads in order of tonnes into low earth orbit. The only real question is, how to cheaply accomplish sustained power output of 5-10 gigawatts or so for around 20 seconds. :)
That part is actually relatively simple. A sustained power supply can be provided by an array of gas turbines.
Or, maybe, a crazier idea - just petrol engines. Silly as it sounds, automotive mass-production experience can allow for production of enlarged big blocks, and simple is cheap. With just $20,000 getting you 1400 horsepower off the shelf, they're an order of magnitude cheaper than turbines. Of course, in the end, it all comes down to whether the maintenance expenses overcome the cost of turbines.

However, I think 10GW is fairly conservative... A 50-ton capsule (for 20-30 ton payload), for instance, would have an energy of 1.6 TJ - that's 80 GW, not 5-10. And that's without the losses, which amount to more energy, at least 3 times that. Still, energy production itself is the lesser issue.

A more costly part is switches to control the coilgun - all this massive power has to switched between the coils in a fraction of a millisecond.


The acceleration caused by curvature would be tricky especially for manned launch. A 30 kilometer curvature to 15 degree angle and velocity of 9 km/s (LEO) would cause around 11g peak acceleration, uncomfortable for sure but not deadly especially as it wouldn't last that long.
That is if 15 degrees is enough. We'd be starting quite near to the ground, so the drag will be enormous. Even at 5km, air is only twice less dense, so the projectile will face immense drag. It both slows it down and requires some unprecedented shielding.
Ultimately, this drag is the main problem of any ground launch. Atmospheric reentry is hard as it is, and here we need to have the highest speed in the most dense layer, not vice versa. The shielding required might make human launch impractical anyway, and rules out small payloads, as they'll simply burn entirely.

Vertical launch offers a bit more flexibility, allowing, for instance, to build a tower over the launch site, and further above that tower, suspend a non-pressurized helium or hydrogen filled tunnel, which AIUI should minimize the drag due to their lower density.
That's not without problems either, though; hydrogen may pose a fire hazard, while helium is too expensive, so can only be used if there's a way to ensure only a little will be lost per launch.

A picture of a popped balloon would have been more effective at illustrating that point.

I imagine a lot of thought would have to go into that aspect of the idea. Since it would be a big problem, should it happen.

Also, for some reason this thread is making me think of "99 Red Balloons."

99 Luftbalons :D (http://www.youtube.com/watch?v=jQYQTFudrqc)