Airship-to-Orbit?

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
eople 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.

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?

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

Brett