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Old June 26th 18, 10:14 PM posted to sci.space.policy
Scott M. Kozel[_2_]
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Posts: 160
Default Towards routine, reusable space launch.

On Tuesday, June 26, 2018 at 7:29:31 AM UTC-4, Jeff Findley wrote:
In article ,
says...

So virtual thing made of unobtainium and which has elements without any
mass.


I see you didn't comprehend what you're reading. Try again. Note in
the above quote that the "heavy tether of circular cross-section" is
modeled "as a set of massive points". These points, that have mass, are
"connected by massless viscoelastic bars"


Since the material is still theoretical, it would be hard to estimate
the tether cross-section.

What might it be? 1/16"? 1/8"? 1/4"? Or thinner or thicker?



The mass is modeled as points. This is a common simplification in an
analysis such as this.

hyperbolic. For lower part numerical simulations show
that the aerodynamic force changes significantly the tether
behavior. After the tether enters the atmosphere, most of
it slows down and falls smoothly;



The simulation showed the upper sections of the tether where it broke
off near geostationary altitude. It showed it snaking, floating in space.

Meaningful atmosphere is roughly 20m in altitude, or if you want to
include stratosphere, 50km in altitude.

So, in the cable falling because it broke at geostationary orbit
scenario, you have some lateral forces in the first 50km and eventually,
so air resistance to the structure falling sideways or diagonally with
perhaps a terminal velocity.

But it will fall, and it will pull down on all the rest of the 39,000 of
cable. But that cable will first and foremost be affected by orbital
mechanics since it is way above atmosphere. And pulling down an object
that has forwrad motion causes it to accelerate that forward motion.

So in space, that should be the primary factor to affect cable
behaviour. And since the cable is going down, any motion imparted in the
first 50km of cable will be 1-dampened by the anchor point (or drag on
ground) 2- have very little chance of "snaking up" the whole length of
the 39,000km of the cable.

Once the cable has mostly fallen to the ground and all you got left is a
few hundred km of cable left, then yeah, atmopshere will play a large
role because it affects a large part of the cable.


I see that it's pointless trying to give you an actual acedemic paper
describing an actual analysis performed by actual qualified researchers.
You clearly don't understand what was presented and go right back to the
handwavium. Ugh.

Hopefully other readers will get more out of the link I posted.

Jeff
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