Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.physics > #703585

Re: Going Up!

Show all headers | View raw

On 9/19/2018 3:29 PM, Edward Prochak wrote:
> On Tuesday, September 18, 2018 at 10:26:43 PM UTC-4, Sergio wrote:
>> On 9/18/2018 8:06 PM, benj wrote:
>>> On 9/18/2018 7:51 PM, Sergio wrote:
>>>> On 9/18/2018 3:29 PM, Edward Prochak wrote:
>>>>> On Tuesday, September 18, 2018 at 2:55:31 PM UTC-4, john wrote:
>>>>>> Odd
>>>>>> “You say the space elevator is impossible. Why?“
>>>>>>
>>>>>> Why don’t you suggest some logical reasons?
>>>>>
>>>>> I think the idea from a space elevator goes back to the 1950s?
>>>>> Let me look.
>>>>> Wow was I wrong:
>>>>> "The concept of a tower reaching geosynchronous orbit was first
>>>>>   published in 1895 by Konstantin Tsiolkovsky.[3] His proposal
>>>>>   was for a free-standing tower reaching from the surface of
>>>>>   Earth to the height of geostationary orbit."
>>>>>
>>>>> The basic idea id over 100 years old!
>>>>>
>>>>>
>>>>> A tower does not work as well as a tether design. With the center
>>>>> of mass slightly above geosynchronous orbit, a cable reaching down
>>>>> to earth's surface provides everything that is needed.
>>>>>
>>>>> No danger of collapse.
>>>>> deployment is achievable, especially with today's rockets.
>>>>>
>>>>> Only the cable is the tough part. material having consistent
>>>>> Tensile strength for a length over 35,000 km (21,000 miles)
>>>>> is a challenge.
>>>>>
>>>>> So what do you do with it?
>>>>>   solar power conversion and transmission to earth (requires
>>>>>                high power transmission lines that long also).
>>>>>   zero gravity manufacturing
>>>>>   Human space travel research (Think ISS but higher)
>>>>>   astronomy observatory
>>>>>   tourism/entertainment/advertisement
>>>>>
>>>>> It would have to be based at an equatorial country, one of
>>>>> 13 countries: Ecuador, Colombia, Brazil, Sao Tome & Principe,
>>>>> Gabon, Republic of the Congo, Democratic Republic of the Congo,
>>>>> Uganda, Kenya, Somalia, Maldives, Indonesia and Kiribati.
>>>>>
>>>>> Really, at this point it is only an engineering problem
>>>>> of building the cables and getting them in place.
>>>>>
>>>>> Enjoy,
>>>>> ed
>>>>>
>>>>
>>>> open questions;
>>>>
>>>> if not a tower, what is holding the cable up ?
>>>> is it a counterweight above geosync ?
>>>> would one still have to fix cable to the ground ?
>>>> how to keep the counterweight in position ?
>>>> is the cable cutting lines of magnetic field?
>>>>
>>> Rumor has it that an experiment was tried with such a cable in space not
>>> as an elevator but as a massive current generator to power some kind of
>>> SDI device. Reportedly the cable broke and the experiment failed. Who
>>> knows if they tried it again. Maybe Sergio knows. He seems tuned into
>>> such things.
>>
>> https://www-istp.gsfc.nasa.gov/Education/wtether.html
>>
>> The Space Tether Experiment
>>
>> Im sure they have done more on this,
>>
>> https://en.wikipedia.org/wiki/Space_tether
>>
>> Pendular motion instability -- what the cable space elevator would have,
>> lots of strange ossicilation modes
> 
> Ah yes. the Tacoma Washington bridge scenario.
> I hadn't thought of that problem. But wouldn't that only
> affect the first few hundred miles of cable? Thinking about it,
> no, it's not limited. The forcing function might only be in the
> atmosphere, but the oscillations would travel the whole length
> of the cable.

and be reflected back at both ends, an oscillation could be 1 to 1000
miles long.

and there is nothing holding the weighted end above the Geosync orbit,
except small positioning rockets (?)   So it could flail about, could
take a year to calm down.

> 
> Another tough problem to solve. It would require some kind
> of dampers at various points. That could add weight to the
> cable system, meaning the tensile strength would need to be
> even stronger. 
> 
> Still seems doable, but VERY hard.
> Ed
> 

the high frequency osc could be damped somewhat.

Back to sci.physics | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Going Up! The Starmaker <starmaker@ix.netcom.com> - 2018-09-04 10:27 -0700
  Re: Going Up! Edward Prochak <edprochak@gmail.com> - 2018-09-04 13:14 -0700
    Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-04 19:09 -0500
      Re: Going Up! Edward Prochak <edprochak@gmail.com> - 2018-09-14 06:26 -0700
        Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-14 07:25 -0700
          Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-14 09:38 -0500
            Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-14 07:43 -0700
            Re: Going Up! benj <benj.fake@gmail.com> - 2018-09-14 11:26 -0400
          Re: Going Up! Edward Prochak <edprochak@gmail.com> - 2018-09-17 10:01 -0700
            Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-17 12:10 -0700
              Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-17 21:24 +0000
                Re: Going Up! mitchrae3323@gmail.com - 2018-09-17 14:34 -0700
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-17 16:12 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-17 23:22 +0000
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 06:29 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-18 14:30 +0000
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 08:13 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-18 16:22 +0000
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 10:28 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-18 18:52 +0000
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 11:55 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-18 20:04 +0000
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 13:11 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-18 21:27 +0000
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 14:30 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-19 00:02 +0000
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 17:20 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-19 00:42 +0000
                Re: Going Up! Edward Prochak <edprochak@gmail.com> - 2018-09-18 13:29 -0700
                Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-18 18:51 -0500
                Re: Going Up! benj <benj.fake@gmail.com> - 2018-09-18 21:06 -0400
                Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-18 21:26 -0500
                Re: Going Up! mitchrae3323@gmail.com - 2018-09-18 19:38 -0700
                Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-18 21:48 -0500
                Re: Going Up! mitchrae3323@gmail.com - 2018-09-18 19:51 -0700
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-19 07:01 -0700
                Re: Going Up! Edward Prochak <edprochak@gmail.com> - 2018-09-19 13:31 -0700
                Re: Going Up! Edward Prochak <edprochak@gmail.com> - 2018-09-19 13:29 -0700
                Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-19 21:00 -0500
                Re: Going Up! Edward Prochak <edprochak@gmail.com> - 2018-09-19 13:14 -0700
                Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-19 21:08 -0500
                Re: Going Up! john <johnsefton288@gmail.com> - 2018-09-18 06:34 -0700
                Re: Going Up! Odd Bodkin <bodkinodd@gmail.com> - 2018-09-18 14:30 +0000
      Re: Going Up! "Chris M. Thomasson" <invalid_chris_thomasson@invalid.invalid> - 2018-09-19 22:37 -0700
        Re: Going Up! Sergio <invalid@invalid.com> - 2018-09-20 10:09 -0500
  Re: Going Up! Haných Ltskáš <lnni@yawlucla.ha> - 2018-09-04 23:08 +0000

csiph-web