Airship-to-Orbit?

[sanman]

Can an airship travel to orbit?

I was surfing at www.jpaerospace.com and they say it can be done.
They have a nice little presentation on PDF that gives a detailed
explanation.

Is it possible that the oldest aerial technology can also be the first
to take the masses to space?

[Orval Fairbairn]

In article >,
(sanman) wrote:

> Can an airship travel to orbit?
>
> I was surfing at www.jpaerospace.com and they say it can be done.
> They have a nice little presentation on PDF that gives a detailed
> explanation.
>
> Is it possible that the oldest aerial technology can also be the first
> to take the masses to space?

NO! An airship requires atmosphere to give ir buoyancy -- the difference
between the mass of the entire ship and the mass of the air displaced.
It cannot fly to vacuum conditions -- balloons have gone to about
120,000 feet.

Also, the speed of an airship is WELL below the required orbital
velocity -- some 200 ft/sec vs tha required 18,000 ft/sec.

[anonymous coward]

On Tue, 25 May 2004 01:41:10 +0000, Orval Fairbairn wrote:

> In article >,
> (sanman) wrote:
>
>> Can an airship travel to orbit?
>>
>> I was surfing at www.jpaerospace.com and they say it can be done.
>> They have a nice little presentation on PDF that gives a detailed
>> explanation.
>>
>> Is it possible that the oldest aerial technology can also be the first
>> to take the masses to space?
>
> NO! An airship requires atmosphere to give ir buoyancy -- the difference
> between the mass of the entire ship and the mass of the air displaced.
> It cannot fly to vacuum conditions -- balloons have gone to about
> 120,000 feet.

I think their idea is to use aerodynamic lift to take the airship to
200,000 feet.

> Also, the speed of an airship is WELL below the required orbital
> velocity -- some 200 ft/sec vs tha required 18,000 ft/sec.

At which point an ion drive will accelerate it to orbital velocity.

I'll look again when it's working, but it's kinda novel (at least to me).

AC

[C J Campbell]

Nice idea, but:

1) They want to build a 6,000 foot long airship using a construction
facility permanently parked at 140,000 feet up. Might be a little tough.
They are probably right in their calculations that it would take an airship
of this size to reach 200,000 feet.

2) They want to use a solar powered electric motor with a propeller over a
period of five days to accelerate the big airship to orbital velocity at
200,000 feet. Aside from the problems of using a big paddle bladed propeller
to reach supersonic speeds, one might ponder the problem of how much drag a
6,000 foot long airship is going to produce. I suspect that the electric
motor will not be able to accelerate the airship to anything near orbital
velocity.

3) But then they want to cruise about the solar system using this same
electric motor for propulsion. For this, the airship must achieve not only
orbital velocity, but escape velocity. It would be especially interesting to
see how they get a propeller to work in the vacuum of space.

[[email protected]]

I suspect that the Prop is only to get to the 140Kft Dark sky Station.
The big gas bag uses solar powered Ion thrustors to get to orbit.
Much better specific impulse than traditional rockets.

The Space nuts at sci.space.tech seem to think that if the air is
dense enough for lift/ boyancy then it is too dense to go fast enough
to get to orbital velocity. The general consensus is that it takes
"impossibly" efficent aerodynamics at an unbelieveibly huge scale.

Very Very cool idea if it works.



On Mon, 24 May 2004 20:15:34 -0700, "C J Campbell"
> wrote:

>Nice idea, but:
>
>1) They want to build a 6,000 foot long airship using a construction
>facility permanently parked at 140,000 feet up. Might be a little tough.
>They are probably right in their calculations that it would take an airship
>of this size to reach 200,000 feet.
>
>2) They want to use a solar powered electric motor with a propeller over a
>period of five days to accelerate the big airship to orbital velocity at
>200,000 feet. Aside from the problems of using a big paddle bladed propeller
>to reach supersonic speeds, one might ponder the problem of how much drag a
>6,000 foot long airship is going to produce. I suspect that the electric
>motor will not be able to accelerate the airship to anything near orbital
>velocity.
>
>3) But then they want to cruise about the solar system using this same
>electric motor for propulsion. For this, the airship must achieve not only
>orbital velocity, but escape velocity. It would be especially interesting to
>see how they get a propeller to work in the vacuum of space.
>
>

[nafod40]

C J Campbell wrote:
> Nice idea, but:
>
> 1) They want to build a 6,000 foot long airship using a construction
> facility permanently parked at 140,000 feet up. Might be a little tough.
> They are probably right in their calculations that it would take an airship
> of this size to reach 200,000 feet.
>
> 2) They want to use a solar powered electric motor with a propeller over a
> period of five days to accelerate the big airship to orbital velocity at
> 200,000 feet.

When I read the article, what I saw was that they wanted to glide the
airship upwards and have it accelerate as it rose, using the positive
buoyancy as it's source of thrust. So it'd be an upside-down glider.
They were proposing to gain much of the airship's escape velocity that way.

[Wright1902Glider]

Um,

What happens to the gas bag once it makes orbit? Am I correct in assuming that
there will be a serious pressure differential between the interior and exterior
of the bag? I'm thinking "World's Largest Baloon Goes POP!" ?????

And what exactly would one make a 6,000' long airship out of that wouldn't be
torn apart by all of the forces acting upon it?

Just wondering,
Harry

[Pete Schaefer]

"Wright1902Glider" > wrote in message
...
> What happens to the gas bag once it makes orbit? Am I correct in assuming
that
> there will be a serious pressure differential between the interior and
exterior
> of the bag? I'm thinking "World's Largest Baloon Goes POP!" ?????

Maybe they're going to stress the skin so that it pops open at the back end,
with the escaping gas supplying thrust.

> And what exactly would one make a 6,000' long airship out of that wouldn't
be
> torn apart by all of the forces acting upon it?

Maybe they got one of those "structural integrity fields" like they use on
Star Trek.

[nafod40]

Pete Schaefer wrote:
> "Wright1902Glider" > wrote in message
> ...
>
>>What happens to the gas bag once it makes orbit? Am I correct in assuming
>
> that
>
>>there will be a serious pressure differential between the interior and
>
> exterior
>
>>of the bag? I'm thinking "World's Largest Baloon Goes POP!" ?????
>
>
> Maybe they're going to stress the skin so that it pops open at the back end,
> with the escaping gas supplying thrust.

Hey, good idea!

I am wondering about possibly using Hydrogen. At the extreme altitudes
considered, I'd think the flammability issue would be much less. And
Hydrogen is significantly more bouyant than Helium. Maybe a mix of the two?

[Pete Schaefer]

The hydrogen issue is more of a psychological one. It's pretty well
understood now that the Hindenburg thing was more a problem of skin
materials that became extremely flamable when heated (chemical change).
Hydrogen fires generally blow themselves out. With a different skin, maybe
only one or two cells on the Hindenburg would have blown out from the
lightning strike.

Still, anytime anyone mentions using hydrogen as a lifting gas....."......OH
NO!!! NOT ANOTHER HINDENBURG!"

And you're right. What little concern you might have about flamability would
pretty much go away, unless you were using regular air for ballast and there
was potential for mixing (which would probably mostly be gone by the time
you got up pretty high).

"nafod40" > wrote in message
...
> I am wondering about possibly using Hydrogen. At the extreme altitudes
> considered, I'd think the flammability issue would be much less. And
> Hydrogen is significantly more bouyant than Helium. Maybe a mix of the
two?

[sanman]

nafod40 > wrote in message >...
> When I read the article, what I saw was that they wanted to glide the
> airship upwards and have it accelerate as it rose, using the positive
> buoyancy as it's source of thrust. So it'd be an upside-down glider.
> They were proposing to gain much of the airship's escape velocity that way.

My understanding is that when they mean electric propulsion, they're
not talking about an electric motor. They mean an electric
ion-thruster, which expels charged ions straight out at very high
velocity. Electric ion-thrusters are supposed to be 5 times as
efficient as chemical combustion rocket engines, propellant-wise, and
they are powered by electricity which a blimp could gather thru solar
energy. But they need to operate in a vacuum or near-vacuum
environment, which is why it might make sense with an airship that is
up where the air is very thin. The problem is that the thrust from an
ion-engine is very low, like a small puff from your lungs, so it can't
really move a big object like a blimp. But ion-engines are very
long-lasting (can operate for tens of thousands of hours before
wearing out) compared to chemical rocket engines. But who wants to
take so long to get to orbit???


There are other types of electric thrusters which can produce more
thrust, such as the VASIMR, they'd need megawatts of power like from a
nuclear reactor. Could the surface area of a blimp gather that much
solar energy?

[Regnirps]

I would think hydrogen would be an obvious choice. Helium molecules are so darn
small that they leak out of practically anything. That is why the coated mylar
party balloons are used instead of latex.

Hydrogen likes to be H2 which is huge compard to a single helium, and lighter
yet stronger materials can be used to hold it.

-- Charlie Springer

[Regnirps]

(Wright1902Glider) wrote:

>Um,

>What happens to the gas bag once it makes orbit? Am I correct in assuming
that
>there will be a serious pressure differential between the interior and
exterior
>of the bag? I'm thinking "World's Largest Baloon Goes POP!" ?????

Ask yourself, what is the difference between almost a vacuum and a vacuum? Not
much. If it will hold 16 lbs/sq in, that is about all you need. Things like
people only blow up in vacuum in fiction. If they did, then immagine what would
happen to a SCUBA diver as they come up through three atmospheres of pressure
change!

BTW, Echo 1 was one of the first US sats and it was a metal film coated balloon
to bounce communications.

-- Charlie Springer

[Richard Riley]

On 28 May 2004 03:11:03 GMT, (Regnirps) wrote:

(Wright1902Glider) wrote:
:
:>Um,
:
:>What happens to the gas bag once it makes orbit? Am I correct in assuming
:that
:>there will be a serious pressure differential between the interior and
:exterior
:>of the bag? I'm thinking "World's Largest Baloon Goes POP!" ?????
:
:Ask yourself, what is the difference between almost a vacuum and a vacuum? Not
:much. If it will hold 16 lbs/sq in, that is about all you need. Things like
:people only blow up in vacuum in fiction. If they did, then immagine what would
:happen to a SCUBA diver as they come up through three atmospheres of pressure
:change!

If it's filled with pure O2, 3 or 4 psi will do it, that's what Apollo
used.

Not that I believe the rest of it, mind you.

[Brett]

The pictures look fake to me. I also get real leary when they ask for donations.

Brett

[C J Campbell]

"Regnirps" > wrote in message
...
> I would think hydrogen would be an obvious choice. Helium molecules are so
darn
> small that they leak out of practically anything. That is why the coated
mylar
> party balloons are used instead of latex.

I have never noticed that helium filled latex balloons lose buoyancy any
faster than the Mylar ones. I thought Mylar was used because it is bright
and shiny. I have also heard that birds are less likely to eat it and die,
which probably ranks right up there with urban legends about wedding rice
and birds. Back in the old days (when I was a child) I used to sell balloons
to raise money for Rotary and the local rodeo. No such thing as Mylar
balloons then, but they were filled with helium. The balloons would hold
their helium for a week or more. I also recall latex weather balloons filled
with helium. Although I personally launched literally thousands of toy
balloons filled with helium, I never heard of a bird being killed by one. I
have seen toy helium filled balloons at 11,000 feet.

When we lived in the Philippines in the 70's they still sold balloons filled
with hydrogen, which has been banned in the US because of its flammability.
Let one of these toys near a lit cigarette and you could have one badly
burned kid.

[Regnirps]

"C J Campbell"

>I have never noticed that helium filled latex balloons lose buoyancy any
>faster than the Mylar ones.

A regular ballon is usually limp in less than 24 hours and useless shortly
after that. The Maylars are good for about a week I think. I either case, I
wonder how much is escaping through the knot or filler adhesive?

-- Charlie Sprinher

[G EddieA95]

>A regular ballon is usually limp in less than 24 hours and useless shortly
>after that. The Maylars are good for about a week I think.

I've had a 12" (30cm) Mylar balloon hold its lift for over a month.

>I either case, I
>wonder how much is escaping through the knot or filler adhesive?

Sometimes a plastic plug is used in He-filled rubber balloons. Might that work
longer?

[Regnirps]

(G EddieA95) wrote:

>Sometimes a plastic plug is used in He-filled rubber balloons. Might that
work
>longer?

It might help a little, but the helium is diffusing right through the rubber.
The stuff is notorious. Many a physics graduate student has spent years chasing
down helium leaks in high vacuum and cryogenic equipment.

-- Charlie Springer

[Ron Wanttaja]

On 29 May 2004 02:58:52 GMT, (Regnirps) wrote:

(G EddieA95) wrote:
>
>>Sometimes a plastic plug is used in He-filled rubber balloons. Might that
>>work longer?
>
>It might help a little, but the helium is diffusing right through the rubber.
>The stuff is notorious. Many a physics graduate student has spent years chasing
>down helium leaks in high vacuum and cryogenic equipment.

Back when I was just a young engineer, the test organization I was in did
leak testing for the fuel tanks for the first Air-Launched Cruise Missiles
(ALCMs). Said tanks were pressurized with helium, with a sniffer to chase
down the leaks.

Ron Wanttaja

[Morgans]

"Ron Wanttaja" > wrote
>
> Back when I was just a young engineer, the test organization I was in did
> leak testing for the fuel tanks for the first Air-Launched Cruise Missiles
> (ALCMs). Said tanks were pressurized with helium, with a sniffer to chase
> down the leaks.
>
> Ron Wanttaja
>
So how did it let you know it found a leak? Did it start talking to you in
a real high, squeaky voice? <g>
--
Jim in NC


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[Ron Wanttaja]

On Fri, 28 May 2004 23:59:27 -0400, "Morgans" >
wrote:

>
>"Ron Wanttaja" > wrote
>>
>> Back when I was just a young engineer, the test organization I was in did
>> leak testing for the fuel tanks for the first Air-Launched Cruise Missiles
>> (ALCMs). Said tanks were pressurized with helium, with a sniffer to chase
>> down the leaks.
>>
>> Ron Wanttaja
>>
>So how did it let you know it found a leak? Did it start talking to you in
>a real high, squeaky voice? <g>

That's why they didn't have *me* do it. They couldn't tell the
difference. :-)

Ron "Patton didn't sound like George C. Scott, either" Wanttaja

[VideoFlyer]

I know this is quite a leap.....but can someone explain to me why breathing
helium causes your voice to go up in pitch? I have never heard a really good
explanation of this phenomenon.

Dave

[Richard Riley]

On 29 May 2004 19:58:03 GMT, (VideoFlyer) wrote:

:I know this is quite a leap.....but can someone explain to me why breathing
:helium causes your voice to go up in pitch? I have never heard a really good
:explanation of this phenomenon.

It's really aerodynamics and Reynolds numbers - but the short version
is something like this.

The sound of your voice comes from your vocal chords vibrating. They
vibrate in the airstream created by you exhaling.

Regular air, which is mostly Nitrogen and Oxygen. is much thicker than
helium. Like it says earlier in this thread, helium atoms are much
smaller than N2 or O2, and they go through passages much easier. It's
like comparing lacquer thinner to maple syrup. The Robinson helo uses
helium to inflate the emergency floats not because it's lighter, but
because it gets through the plumbing faster, so the floats inflate
faster.

So, when helium goes past your vocal chords it doesn't exert much
force on them. In order to get them to vibrate, your mussels have to
pull them much tighter - which means, when they do vibrate, they're
vibrating much faster, light a tight guitar string vrs a loose one.

[anonymous coward]

On Sat, 29 May 2004 19:58:03 +0000, VideoFlyer wrote:

> I know this is quite a leap.....but can someone explain to me why breathing
> helium causes your voice to go up in pitch? I have never heard a really good
> explanation of this phenomenon.
>

My understanding was that the speed of sound in Helium is higher than the
speed of sound in air (about 3x faster). I think this is because helium
atoms are lighter, so to exert the same pressure they need to move faster.

If you take a resonant cavity of fixed length - like a hunting-horn - then
the wavelength of the fundemental is fixed. But if it is filled with
helium, the speed of sound is higher, so the frequency that has this
wavelength is also higher (Speed of sound = Wavelength x frequency).

I think the combination of your voice-box, windpipe, lungs and mouth also
works as a resonant cavity - though it's clearly more complex than the
parabolic shape of a hunting-horn cross-section and other effects may be
involved.

I'm not 100% sure whether my explanation is correct, or even whether it
contradicts that of Richard Riley - but I'm left wondering whether the
maximum frequency of your voice goes up if you inhale helium. According
to my explanation, I expect it would.

In a hunting horn, the highest note I can ordinarily play is certainly
limited by how taut I can make my lip-muscles. I assume the limit to the
tautness of my voice-box also sets the highest note I can sing. If Richard
Riley's explanation holds, I would predict your voice should go up as you
inhale helium but its maximum pitch should stay the same.

nb... I'm told the helium in party balloons contains lots of hydrocarbon
gases and can stop your heart if you inhale it and get unlucky.

[Regnirps]

anonymous coward

>nb... I'm told the helium in party balloons contains lots of hydrocarbon
>gases and can stop your heart if you inhale it and get unlucky.

Could be. Most old helium comes from natural gas wells and used to be stored in
big tank farms as the national helium reserve. Today, you can get helium from a
liquid air plant that is close to pure.

I have always been afraid of taking big breaths of ANYTHING with no oxygen in
it. I don't need some sort of reverse osmosis of oxygen leaving my blood. To
experiment with helium and voices I would recommend heliox mixed gas from a
technical diving establishment.

-- Charlie Springer

[Richard Lamb]

anonymous coward wrote:
>
(Speed of sound = Wavelength x frequency).


???

[Regnirps]

Richard Lamb wrote:

>anonymous coward wrote:
>> (Speed of sound = Wavelength x frequency).

>???

Wavelength meters, frequency 1/sec, gives meters/sec = speed

-- Charlie Springer

[anonymous coward]

On Mon, 31 May 2004 02:23:15 +0000, Regnirps wrote:

> Richard Lamb wrote:
>
>>anonymous coward wrote:
>>> (Speed of sound = Wavelength x frequency).
>
>>???
>
> Wavelength meters, frequency 1/sec, gives meters/sec = speed

Or alternatively:

Wavelength (yards/1760), frequency (cycles/hour) = speed (miles per hour)

(for the benefit of American readers)

AC

> -- Charlie Springer

[Richard Lamb]

anonymous coward wrote:
>
> On Mon, 31 May 2004 02:23:15 +0000, Regnirps wrote:
>
> > Richard Lamb wrote:
> >
> >>anonymous coward wrote:
> >>> (Speed of sound = Wavelength x frequency).
> >
> >>???
> >
> > Wavelength meters, frequency 1/sec, gives meters/sec = speed
>
> Or alternatively:
>
> Wavelength (yards/1760), frequency (cycles/hour) = speed (miles per hour)
>
> (for the benefit of American readers)
>
> AC
>
> > -- Charlie Springer

Funny.

I thought frequency was the inverse of wavelength.

x time 1/x = 1 ???

[Regnirps]

Richard Lamb wrote:

>Funny.
>I thought frequency was the inverse of wavelength.
>x time 1/x = 1 ???

Perhaps you are thinking of a vibrating string as in a guitar where the
frequency is determined by the tension and mass per unit length and wavelengths
have to be integer multiples of the length of the string.

The speed is fixed by the speed of a displacement wave in the string and can be
ignored.

When you use half the string you get twice the frequency.

-- Charlie Springer

[B2431]

>From: Richard Riley
>Date: 5/27/2004 10:21 PM Central Daylight Time
>Message-id: >
>
>On 28 May 2004 03:11:03 GMT, (Regnirps) wrote:
>
(Wright1902Glider) wrote:
>:
>:>Um,
>:
>:>What happens to the gas bag once it makes orbit? Am I correct in assuming
>:that
>:>there will be a serious pressure differential between the interior and
>:exterior
>:>of the bag? I'm thinking "World's Largest Baloon Goes POP!" ?????
>:
>:Ask yourself, what is the difference between almost a vacuum and a vacuum?
>Not
>:much. If it will hold 16 lbs/sq in, that is about all you need. Things like
>:people only blow up in vacuum in fiction. If they did, then immagine what
>would
>:happen to a SCUBA diver as they come up through three atmospheres of
>pressure
>:change!
>
>If it's filled with pure O2, 3 or 4 psi will do it, that's what Apollo
>used.
>
>Not that I believe the rest of it, mind you.
The low pressure in the Apollo spacecraft had more to do with the space suits
than structural integrity of the spacecraft. Space suits lose flexibility as
inside to outside presure ratio increases. They kept the pressure in the
spacecraft low to avoid having to slowly decompress before landing on the moon.
I believe the shuttle does it for the same reason.

An amusing aside: when White did his space walk from a Gemini his suit swelled
to the point he couldn't get back in until they bled off pressure.

Dan, U.S. Air Force, retired

[Regnirps]

(B2431) wrote:

>The low pressure in the Apollo spacecraft had more to do with the space suits
>than structural integrity of the spacecraft. Space suits lose flexibility as
>inside to outside presure ratio increases. They kept the pressure in the
>spacecraft low to avoid having to slowly decompress before landing on the
moon.
>I believe the shuttle does it for the same reason.


I believe it, but the partial pressure of oxygen in the atmosphere at sea level
is about 3.5 lbs/sq in. , so you don't need any more than that. In fact unless
there are other low pressure problems like osmotic gradients in the lungs or
something, you should be able to run fine at one or two pounds of straight O2.

-- Charlie Springer

[Model Flyer]

"Morgans" > wrote in message
...
>
> "Ron Wanttaja" > wrote
> >
> > Back when I was just a young engineer, the test organization I
was in did
> > leak testing for the fuel tanks for the first Air-Launched Cruise
Missiles
> > (ALCMs). Said tanks were pressurized with helium, with a sniffer
to chase
> > down the leaks.
> >
> > Ron Wanttaja
> >
> So how did it let you know it found a leak? Did it start talking
to you in
> a real high, squeaky voice? <g>

Naaaa Jim, the little buzzer thingy went very high pitched.:-)
--
---
Cheers,
Jonathan Lowe.
/
don't bother me with insignificiant nonsence such as spelling,
I don't care if it spelt properly
/
Sometimes I fly and sometimes I just dream about it.
:-)

> --
> Jim in NC
>
>
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>