Beanstalks were discussed longer ago more in detail but my oldest ARocket
emails I considered of interest (saved on HD) stop at 2000.
So as I understand it the top anchor mass beyond *is* in orbit and since
above GEO acts as a non-sync stalk puller. The bottom need not be attached
as it can hover in the atmosphere. The hovering stalk as a whole is mainly
straight and keeps pointing to the Earth's center. But what happens if the
stalk is attached to a fixed launch base on the Earth and a non-synchronous
sat?
Any good book on the subject?
jd
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On
Behalf Of Rand Simberg
Sent: donderdag 22 september 2016 15:48
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Space elevators... was: Ozone layer
A beanstalk isn't in orbit, and doesn't need to be "kept" there. It is
tensioned by the centripetal acceleration of the anchor beyond GEO.
On 2016-09-22 05:30, David Summers wrote:
It could work - the cable near Earth is in tension anyway so it
doesn't matter that it goes straight down or not. You would need the
mass that is beyond you to be in a slightly different direction than
normal but that shouldn't cause real issues. The difficulty would be
that the cable is not pulled around with Earth's motion as easily.
Only the atmosphere would be exerting force on the cable which would
seem to not be enough to keep it in orbit.
On Sep 22, 2016 7:27 AM, "John Dom" <johndom@xxxxxxxxx> wrote:
I dare say polar beanstalk confuses me. Like a slingshot with radius
zero.
jd
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx
[mailto:arocket-bounce@xxxxxxxxxxxxx] On Behalf Of Rand Simberg
Sent: donderdag 22 september 2016 0:12
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Space elevators... was: Ozone layer
Having it off the equator results in additional tension. It would be
interesting to look at the case where you attach it to a pole.
On 2016-09-21 15:04, Evan Daniel wrote:
Yes, the cable is slightly slanted and the payload experiences athe
horizontal acceleration. It's a form of Coriolis effect. (However,
cable is quite heavy in relation to the payload, so the slant isI
slight.)
The cable doesn't need to be at the equator, just kind of near it.
think the strict equatorial requirement is a popularmisconception.
That said, I believe putting it closer makes dynamics andattachment
both a little better. (It's been a while since I read detailshere,
someone will hopefully correct me if needed...)times.
Evan Daniel
On Wed, Sep 21, 2016 at 5:37 PM, Peter Fairbrother
<zenadsl6186@xxxxxxxxx> wrote:
On 21/09/16 20:49, Derek Clarke wrote:
Your country was settled with the aid of multi-month transit
orbit,The
whole point of a beanstalk is to reduce the energy cost to
annualand a longer transit seems a good tradeoff to me.
I don't think longer transit times matter directly, but overall
to becapacity does. The longer the transit time, the more cargo needs
thehanging on the wire at once, for a certain annual capacity - and
ground,amount
of mass which the wire can handle is limited.
Something which has often puzzled me - cargo starts on the
velocity ofwith a
velocity of around 250 m/s, then is released in GEO with a
then3
km's. Where does the extra momentum come from?
If it's from slowing the Earth (should Greenpeace be worried?),
thepresumably the wire is slightly slanted.
I don't see why not, but people insist an elevator needs to be on
equator, as if it wasn't on the equator then the cable would be
slanted.
Confused,
-- Peter Fairbrother
