You can look at the simulations of broken space elevator cables at
https://gassend.net/spaceelevator/breaks/index.html

I don't know that guy and I haven't validated his simulations but I have
no reasons to believe that his simulations are not accurate.


Alain Fournier


On Jun/15/2020 at 04:34, JF Mezei wrote :
On 2020-06-14 06:51, Alain Fournier wrote:

Not really. At very first, yes that is what will happen. The bottom part
will pull the cable down under some tension. This will cause parts
higher up to go eastward.

In wanting to go eastward, won't the cable also end up pulling up
because wanting to go faster will only work for so long until the slack
is gone and the increased speed is decelerated back to geosynch speed of
one orbit per 24 hours?




Pieces higher up will start going eastward
slower than pieces in the middle, but with time the pieces higher up
will get more eastward speed than those in the middle. You get a chaotic
result, the cable breaks at multiple places.

So if the cable between LEO and Geo breaks up, won't each individual
segment just drop till they are at an orbital speed that matches their
altitude?

For pieces low enough, they won't have enough altitude to convert a
droip in altitude into horizontal speed enough to stay in orbit, so they
will hit atmosphere and drop to sea level.

So assuming such a tether has separateion mechanism, not all of it would
fall down since pieces high enough to achieve orbital speed as they drop.

And if it breaks up into seperate segments, it also means that the
"heavy" segments near ground stop pulling down thosesegments near geo.

The cable will give some negligeable amount of eastward spin to the
planet when it falls. I'm not quite sure what you mean by "the spin the
planet gave up

I was thinking about the spin the Earth woudl give up when it
accelerates the elevators as they rise. But you're right in that the
cable itself is more likely to be assembled with rocket engines
accelerating it.





More imkportantly, will a 36,000km cable end up almostly circling the
equator (40,000) as it falls, or will there be significant amounts of
cable that will be piulot onto itself, greatly reducing the distance
covered as the cable falls back down?

Sorry, I can't parse piulot.

Sorry, pile up. Assuming the cable doesn't break, would it fall down
drawing a stright line towards the east that almost goes around all the
globe? Or woulf there be periods where the cable piles up onto itself,
then perhaps moves some, pules up again (at which point the whole
36,000km of cable make span perhaps just 1000km, with piles containing
36km of cable left every 10km.

No. A cable in orbit will always take a vertical orientation because of
tidal forces.

Sorry for basic orbital mechanic quaestion: say you have a 1000km cable
which is vertical, and the top at 36,000km altitude. (lets say for sake
of discussion geostationary is 36,001)

So a piece at 36,000 altitude is going at 9424km/h when on tether.
The piece at 35,000 altitiude is going ay 9162km/h. Both have sale
360°/24 hours angular speed.

Now, say the whole segment drops 1000km. How will the speeds of each
end accelerate relative to each other? Will the top end up with more
angular speed than the bottom? Or vice versa? Or would it remain
strictly the same?

If either side wants to accelerate horizontally more than the other,
won't the cable end up near horizontal eventually?