Airship-to-Orbit?

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?

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.

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

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.

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.

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.

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

"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.

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?

(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