Re: coils in space

["Jim Lux" <jimlux-at-jpl.nasa.gov> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

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> From: Tesla list <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: coils in space
> Date: Sunday, August 06, 2000 9:27 PM
> 
> Original poster: "Metlicka Marc" <mystuffs-at-orwell-dot-net> 
> 
> hello all,
> if a tc was fired in space, then it would become a propulsion unit.
> nasa's tethered satellite project is studying this effect for satellite
> propulsion and orientation. a current flow in one direction is a
> generator, the other is a propulsion.
> the second failure of the tethered satellite was due to a spark from the
> conductor to the ship unit, this was due to the unimagined amount of
> energy that this system produced.

Perhaps unanticipated distribution of energy, but certainly not unimagined.
 It was also a bad design that didn't have proper redundancy.  The actual
power was fairly low. It just happend that a spark eroded the very small
cable, and then it catastropically failed.



> even in deep space the topload of the coil would probably give off a
> glow when running because space is a very dirty vacuum,(and i guess the
> densest substance in the universe could be considered the dirtiest
> vacuum) there is always present very thin atomic structure. 

Actually, a fairly good vacuum.  Comparable to that in a vacuum tube

A long post copied from the Fusor Bulletin Board from Richard Hull, quoting
from Electric Spacecraft Journal, gives all this stuff:

1. At sea level there are about 2X10e19 gas molecules in each cubic cm of
space. That is 
over 20 quintillion molecules banging against one another at hypersonic
velocities that would put to shame the fastest rifle bullet. All in a 1/3
inch cube! 

2. At sea level there are very few free electons, being less than 10 per
cc. 

3. Thirty miles up, in the stratopause, we have a near equivalent of the
Martian atmosphere at just a few mm or torr or pressure. There are still
about 100 quadrillion air molecules per cc at this level. 

4. At 50 miles up the atmosphere is just thick enough so that things moving
5 miles/second heading down start to heat up due to friction with the air
molecules. (meteors start to burn - Spacecraft re-entering heat up). There
are now only a mere 100 Trillion molecules per cc and the pressure is at
10e-2 mm (torr) or 10 microns. This is about the pressure that most
mechanical vacuum pumps start balking as they are out of transitional flow
and deep into molecular flow. 

5. At 60 miles (beginning of the E Region) the pressure is on the order of
1 micron with still about 10 Trillion or so molecules in every cc of space.
This is where most simple fusors are fusing and represents the absolute
realizable, sustainable, limit of a well maintained, standard, two stage
mechanical pump. 

6. The E Region is the region where aurora occur and extends from 60 miles
(10e-3 torr) to ~90 miles (10-5 torr). At the very extreme high end of this
region, we still have about 100 billion gas molecules jammed into that same
little 1/3 inch cube. This is about the level of operation of a vacuum
system sporting a poorly operated oil diffusion pump. This is also the area
(10e-5 torr) where the practical limit of the earth's atmosphere is reached
and a near frictionless orbit is possible. (frictionless!!!? with 100
billion molecules/cc?.........You Betcha). 

7. The space shuttle normally orbits in the upper F1 region at around 130
to 140 miles. The outside pressure is about 10e-6 torr or in the middle of
the high vacuum range about where a decent diffusion pump works without
operational heroics or cryotraps. This is about where most ion pumps are
turned on to go to higher vacuums. 
there ae now only one Billion gas atoms in a cc or space. (still sounds
like an awful lot..don't it?) 

8. Our best diff pumps play out some where are about 180 miles and 10e-7
torr. This is the middle of the F2 region. Still over 100 million
molecules/cc. Interestingly, the number of free electrons in the atmosphere
peaks in this region after steadily rising with altitude. There are about
10 million free electrons/cc at the transition of the F1 and F2 regions 155
miles up. This makes this the most conductive portion of our atmosphere.
Free electrons will now slowly decline with altitude as the number of gas
atoms decrease. 

9. At about 250 miles where the space station MIR orbits, we have a vacuum
of about 10e-8 torr. 

10. The Hubble Space Telescope orbits at about 370 miles and the pressure
is near 10e-9 torr or about where UHV (ultra-high vacuum)starts for the
professional vacuumist. We are now in the range of millions of
molecules/cc. 

11. At 450 miles we reach the pressure of about 10e-10 torr. Between 450
and 600 miles the pressure can rise or fall depending on solar wind and
other variables. 

12. Above 600 miles the pressure falls off to 10e-11 which is about the
lowest I have personally ever witnessed in a pulled down vacuum system (not
mine). This is near the upper limit of worldly vacuum systems with all the
bells and whistles such as ion pumps, Ti sub pumps and other getter and
cryo traps. Also most gauges of even the most sophisticated types get
"flakey" beyond here. 

13. The finest and most meticulously maintained vacuum systems can hit the
deep space vacuum of 10e-12 torr which represents only a few tens of
thousands of gas atoms/cc. 

14. I am given to understand that, with ungodly expensive, super cooled,
liquid He at below 4 degrees kelvin, the Jefferson National Labs here in
Virginia, which has the most potent continuous electron beam accelerator in
the world, the vacuum they achieve is just simply not measurable and is
certainly greater than 10e-14 torr. The head engineering expert at CBAF who
attended our meetings when he was here in VA, said that if their best
gauging efforts read anything at all they knew they had to keep pumping. He
estimated fewer than several hundreds of remenant atoms existed per CC.
This level is most likely a nearly interstellar level of vacuum, but no one
has ever really measured that. 

even in the
> cleanest vacuums created there can not be a true vacuum because a pure
> vacuum would be defined as an absence of matter.  it has been found that
> in a very high vacuum that electrons and protons appear and disappear at
> random. it would seam that a high vacuum is a sink that wants to be
> filled. thus Einstein's theory of the energy potential in a cubic yard
> of vacuum.
> marc
> 
> 
>