OK EVERYONE THIS IS WICKED COOL!

Two large Stanford toruses ( "tori"?) connected by a large common shaft. Each habitat rotating in opposite direction. The common shaft is large and where docking and microgravity work is done. The common shaft uses magnetic bearing to connect frictionless with both habitats.

The cool thging here is the whole complex will be s'pun up" using "Linear "motors/generators (like maglevs) located between the shaft and the torus. This way both habitats will serve as power storage devices. If the complex is pulling in more energy than it needs it can be stored as torus spin. Plus the magnetic bearing would be used to control instablities by adjusting the field strength at different places.

Here is another thought about magnetic fields. They could be important for protection during a large solar flare. And there was some work talking about magantic fields used for propulsion, like sails in the solar wind, why not have the habitat start traveling to different orbits, like say first to venus and mercury to take advantge of discover and the increase in usable power from solar energy.
You could have this "city-state" college meant to spend 20 years orbiting Venus and learning and experimenting with the sister planet and have another orbit and explore mercury

Mercury is perfect for metals and if there was a way to "mine" Venus's atmosphere of it's contents CO2, water and sulfuric acids would be useful.

I hate talking like this when it is so expensive to get into LEO right now.
I just dream of the majority of human beings living off world on habitats, astroids,moons and planets.
BestRegards,
Pete

GARY ANSORGE wrote: Precession depends upon the application of a force at
right angles to the direction of rotation. On Earth,
this force is gravity. Since the gyro/torus is in free
fall, this force is negligible, therefore there should
be no substantive precession.

Gary 7

> I think the torus design has precesion issues. Think
> of it as a slow top.
>
> The way around this was highlighted in Kubrick's
> movie
> of Clarke's 2001 book. Two parallel torus connect by
> a
> common shaft.
>
> Another variation on the torus was the Baseball
> Design
> of Star Trek: Deep Space Nine.
>
> David
>
> > Maybe it is better to go with an inherently stable
> > design, such as a torus.
> >
> > Ed
> >
> > > Systems are rather interesting. ..we can classify
> > > them in a number of
> > > ways.
> > >
> > > COmpletely passive, reinforced,
> passive-reactive,
> > > active-reactive.
> > >
> > > For space, passive would be the basic structure.
> > > Reinforced would
> > > allow a structure to bend with the environment
> > > without tearing itself
> > > apart through twisting or resonance.
> > >
> > > Passive-reactive is where aerodynamic forces
> > (space
> > > dynamic in our
> > > case) are reacted to by a dynamic system.
> However,
> > > it may be one shot
> > > or reusable.
> > >
> > > Active-reactive would include systems where
> weight
> > > in the form of
> > > solids, liquids and gases are moved about in
> such
> > a
> > > way to maintain
> > > control. Damping out of mass movements either at
> > the
> > > object level or
> > > within the object (creep, center of mass,
> surface
> > > transitions, etc.)
> > >
> > > Structures in space have no foundation - no
> earth
> > -
> > > to help dampen or
> > > control external or internal forces. In space,
> > there
> > > is weather mostly
> > > from the sun that must be dealth with
> constantly.
> > >
> > > An active-reactive system can be very expensive.
> > > However, engineers
> > > try to reduce the active to a passive problem.
> > >
> > > The biggest worries in space for a long cylinder
> > are
> > > resonance waves
> > > where small forces generate end to end waves
> that
> > > buildup and
> > > overwhelm any system. Torquing is also a major
> > > worry.
> > >
> > > The way to make the long cylinder to work is an
> > > exoskeleton bracing
> > > such that the thickness of the "skin" is at
> least
> > 2%
> > > of the diameter.
> > > For 5 miles diameter, this would be 0.1 or 500
> > feet
> > > of structure
> > > although with a buckyball (see your soccerball)
> > > technique, that might
> > > be reduced to 50 feet or so.
> > >
> > > David
> > >
> > > --- In ssi_list@... s.com, Ed Minchau
> > > >
> > > > These towers would act much like the spokes of
> a
> > > > wheel-shaped station, and might be a good idea
> > for
> > > > structural and aesthetic reasons. However,
> for
> > > > rotational stability (and indeed, any critical
> > > > systems) one would want things to be inherent
> in
> > > the
> > > > design. Critical systems that are active
> rather
> > > than
> > > > passive would be very vulnerable and also lead
> > to
> > > the
> > > > possibility of a "chain reaction" failure,
> where
> > > one
> > > > system going down leads to another going down
> > and
> > > so
> > > > forth.
> > > >
> > > > Ed
> > > >
> > > > --- ForDutyAndHumanity IAmSpacebearAICDA
> > > >
> > > > > How about an active system to keep the
> > cylinder
> > > > > stable.
> > > > >
> > > > > I know that what everyone loves about the
> > O'Neal
> > > > > cylinder is the large spacious feeling. But
> it
> > > would
> > > > > add to the strength of the structure and
> > permit
> > > > > active stablization of the cylinder by
> bulding
> > > large
> > > > > skyscrapers/ building which are the internal
> > > diameter
> > > > > of the cylinder.
> > > > > People could live and work in these
> buildings.
> > > > > elevators would provide easy transport from
> > one
> > > side
> > > > > or the other. But the active stablizing
> system
> > > could
> > > > > be ,lakes at the base of each building,
> pumps
> > > could
> > > > > pump the water up to the weightless center
> of
> > > the
> > > > > building. It would work the same way as
> when
> > > ice
> > > > > skater pull in their arms to spin faster.
> > > > >
> > > > > You could wire the whole cylinder with
> stress
> > > and
> > > > > acceration sensors to provide the
> information
> > > for
> > > > > how the pumps would work.
> > > > >
> > > > > So these building or even a cross structure
> > > would
> > > > > provide added strength to the cylinder,
> places
> > > to
> > > > > live and an active stabilty system. Plus
> > > tourist
> > > > > would love the microgravity living in the
> > middle
> > > of
> > > > > these buildings.
> > > > > BestRegards,
> > > > > Pete
> > > > >
> > > > >
> > > > > ------------ --------- --------- ---
> > > >
> > > >
> > > >
> > > > Be smarter than spam. See how smart
> > > SpamGuard is at giving
> > at
>

____________ _________ _________ _________ _________ _________ _

On Jun 18, 2007, at 18:50 UTC, ForDutyAndHumanity IAmSpacebearAICDA

> Two large Stanford toruses ( "tori"?) connected by a large common
> shaft. Each habitat rotating in opposite direction. The common
> shaft is large and where docking and microgravity work is done. The
> common shaft uses magnetic bearing to connect frictionless with both
> habitats.

I don't think magnetic bearings are necessary. But they might be nice.

> The cool thging here is the whole complex will be s'pun up" using
> "Linear "motors/generators (like maglevs) located between the shaft
> and the torus. This way both habitats will serve as power storage
> devices. If the complex is pulling in more energy than it needs it
> can be stored as torus spin.

Neat -- when there's an energy crisis, at least you get lighter. And
when you wake up pinned to your bed unable to move, you know those new
solar panels were brought online. :)

> Here is another thought about magnetic fields. They could be
> important for protection during a large solar flare.

Only really, obnoxiously, ridiculously strong ones. They studied this
in the 1970s and concluded that it probably wasn't practical (which is
saying something considering all the challenges that were considered
quite reasonable by the same group!).

> And there was
> some work talking about magantic fields used for propulsion,
> like sails in the solar wind, why not have the habitat start
> traveling to different orbits, like say first to venus and mercury to
> take advantge of discover and the increase in usable power from solar
> energy.

In science fiction, if two technologies use some of the same words, you
can sometimes sort of fudge them together as if they're the same thing.
But even then, I wouldn't expect someone to go all the way from
magnetic bearings to magnetic sailing around the solar system protected
by plasma (magnetic) shields!

Best,
- Joe

Joe Strout -- joe@...
Strout Custom Solutions

SSI spends a lot of time thinking about large scale
structures, reminiscent of planet Earth, so large they
have internal weather patterns, clouds, etc. Such
structures will eventually be built, but not until
there is a lot of money being made in space(by a lot,
I mean upwards of trillions of dollars). Getting from
where we are to where we would like to be requires we
also think of prefab, rotating construction shacks,
capable of providing a livable environment(and
G-force) for the folk who have to build power sats and
other large structures via tele-operated 'bots. The
shack on a tether concept could provide such, with two
shacks 867 meters apart rotating about a common center
of gravity. If each shack is 30 meters in diameter and
30 meters tall, with floors 4 meters apart, there is a
lot of usable space in each, to the tune of 4725
square meters/each shack. Ceilings 4 meters high would
be adequate for livability and a connecting shaft
between the two shacks would allow personnel access to
each shack. Living quarters on the first three
"floors" of each provide 675 square meters/floor. At a
population density of 10 square meters per person, we
could house 405 people, provide entertainment on one
floor and still have 3 floors/each shack for work,
labs, power generation(though the center of rotation
is a fine place to put a utility "shed"), even a floor
for green growing things, though perhaps distributing
the green life throughout the shacks might be a better
idea. Everybody remember to water your tomatoes,,,

Oil workers on construction/drilling rigs in the gulf
of Mexico make do with far less. Of course, they get
to return to the mainland several times a year, an
aspect I would think unlikely for workers in orbit,
but a ground based vacation once a year should be
feasible.

There is a company planning on building hotels in
orbit from expandable vinal structures. The plastic is
inflated to the required dimensions and if the
material is thick enough, provides good radiation
protection. Of course, these are all designed for free
fall, rather than a rotating structure, but strapping
on a tether and connecting two such together might be
feasible.

Gary 7

--- ForDutyAndHumanity IAmSpacebearAICDA

Magnetic bearings, eh? OK.

Here's what you do: you take your two twenty mile long, four mile wide
cylinders, and you lop one endcap off each (actually, it'd probably
be best to just not build those two endcaps in the first place).
Place the two cylinders end to end, about a mile apart. Then you take
a one mile long cylinder (still four miles wide) and attach it with
your magnetic bearings to the two cylinders.

Now do the usual filling with air, landscaping, and so on. At the end
of your big cylinder which connects to your non-rotating connector,
have that sci-fi cliche, a moving sidewalk. The slidewalk has hand
rails and is not moving when you step aboard. It wraps around the
whole 12.566370614359172953850573533118 mile circumference. Once you
get aboard it, grab the hand rails and be "de-spun" so that you step
into the non-rotating section without injury. You now have a four
mile wide, one mile long zero-G playground and/or work center. Use
another slidewalk to "re-spin" in the opposite direction if you want
to enter the other cylinder.

That number, 12.566370614359172953850573533118, now that's
interesting. We could play with that. But first, what do you think
of my connector thing-a-ma-bob?

> Here's what you do: you take your two twenty mile long, four mile wide
> cylinders...
> Place the two cylinders end to end, about a mile apart. Then you take
> a one mile long cylinder (still four miles wide) and attach it with
> your magnetic bearings to the two cylinders.

That's interesting. At 1 G, a cylinder with a 2 mile (3219 m) radius
needs to speen 0.528 RPM... which sounds slow, but in linear terms it's
about 178 m/sec (400 mph). That's pretty fast. You'll definitely need
some moving sidewalks to transition from one section to the other. But
rather than one slidewalk that speeds up and slows down, I'd suggest 80
of them, each moving 5 mph faster or slower than the one next to it.
Then you can have continuous traffic in both directions.

I'm not sure whether such a system would be stable, however. Sure, it
has a net angular momentum of zero, but only as a whole -- the parts
have decidedly nonzero momentum, and I suspect the physics of the
forces between those parts could get a bit hairy.

Best,
- Joe

Joe Strout -- joe@...
Strout Custom Solutions

At 400 mph rotation with 1 G, I would be more concerned about human
balance conditions with the inner ear. Some sort of disorientation is
likely with that spinning.

Keep in mind that the 1 G is from rotation only, not from earth-moon-
sun gravitational influences.

Tidal effects would need to be dampened, or constructively used in a
stability system.

David

>
> > Here's what you do: you take your two twenty mile long, four mile
wide
> > cylinders...
> > Place the two cylinders end to end, about a mile apart. Then you
take
> > a one mile long cylinder (still four miles wide) and attach it
with
> > your magnetic bearings to the two cylinders.
>
> That's interesting. At 1 G, a cylinder with a 2 mile (3219 m)
radius
> needs to speen 0.528 RPM... which sounds slow, but in linear terms
it's
> about 178 m/sec (400 mph). That's pretty fast. You'll definitely
need
> some moving sidewalks to transition from one section to the other.
But
> rather than one slidewalk that speeds up and slows down, I'd suggest
80
> of them, each moving 5 mph faster or slower than the one next to it.
> Then you can have continuous traffic in both directions.
>
> I'm not sure whether such a system would be stable, however. Sure,
it

> At 400 mph rotation with 1 G, I would be more concerned about human
> balance conditions with the inner ear. Some sort of disorientation is
> likely with that spinning.

Nope. Disorientation results from the Coriolis effect, which relates
to the rotations per minute, not the linear velocity. Anything under 2
RPM is fine; this is WAY under that. (And from what I've read, I
believe you could go as high as 3 RPM without upsetting most people.)

This is why the classic designs are so big -- they have to be big, in
order to get the spin rate down to a level considered acceptable. This
design is even bigger than that. I bet you wouldn't even notice the
Coriolis effect on this thing if you were playing baseball.

> Tidal effects would need to be dampened, or constructively used in a
> stability system.

True. 3 miles long and 4 miles across... that's a real beast!

But wait a second here... we don't need to divide this and split it
into three 1-mile-long sections or any of that, at least not for the
sake of stability. Or at least, we just barely do. If we shorten it a
bit to 2.6 miles long, and keep the radius at 2 miles, then we can make
it one solid piece, just spin the whole dang thing, and dispense with
the bearings and moving sidewalks and whatnot. (And removing 160
moving sidewalks will make up for some of the lost space.) It'd be
like a giant version of Kalpana One.

Cheers,
- Joe

Joe Strout -- joe@...
Strout Custom Solutions

Joe,

You are correct that inner ear disorder results from
coriolis effect.

However, there is a disorientation effect (space
sickness) that only Jack Sparrow would appreciate
(down is up). Rusty Schweikert was the first to
experience difficulty in space when transfering from
the module to the LEM on Apollo 11 (as I recall).
Frank Sinatra immortalized the song Dancing on the
Ceiling but Lionel Ritchie immortalized the video. And
in 2001 (the movie), we observe the disorienting
effect although some of the Star Wars sequences can be
disorienting as well.

In any case, space is a whole new game. As we try new
things, we must not fool ourselves into thinking a
little math will predict human behavior. Humans have
always been the wildcard in any expedition of any
magntitude especially when you put them in a box.

David

>
> > At 400 mph rotation with 1 G, I would be more
> concerned about human
> > balance conditions with the inner ear. Some sort
> of disorientation is
> > likely with that spinning.
>
> Nope. Disorientation results from the Coriolis
> effect, which relates
> to the rotations per minute, not the linear
> velocity. Anything under 2
> RPM is fine; this is WAY under that. (And from what
> I've read, I
> believe you could go as high as 3 RPM without
> upsetting most people.)
>
> This is why the classic designs are so big -- they
> have to be big, in
> order to get the spin rate down to a level
> considered acceptable. This
> design is even bigger than that. I bet you wouldn't
> even notice the
> Coriolis effect on this thing if you were playing
> baseball.
>
> > Tidal effects would need to be dampened, or
> constructively used in a
> > stability system.
>
> True. 3 miles long and 4 miles across... that's a
> real beast!
>
> But wait a second here... we don't need to divide
> this and split it
> into three 1-mile-long sections or any of that, at
> least not for the
> sake of stability. Or at least, we just barely do.
> If we shorten it a
> bit to 2.6 miles long, and keep the radius at 2
> miles, then we can make
> it one solid piece, just spin the whole dang thing,
> and dispense with
> the bearings and moving sidewalks and whatnot. (And
> removing 160
> moving sidewalks will make up for some of the lost
> space.) It'd be
> like a giant version of Kalpana One.
>
> Cheers,
> - Joe
>
> --
> Joe Strout -- joe@...
> Strout Custom Solutions
>

Luggage? GPS? Comic books?

> Rusty Schweikert was the first to
> experience difficulty in space when transfering from
> the module to the LEM on Apollo 11 (as I recall).

The Apollo 11 astronauts were Armstrong, Aldrin, and
Collins. Rusty Schweickart was on Apollo 9, and yes
he did experience space sickness.

> As we try new
> things, we must not fool ourselves into thinking a
> little math will predict human behavior.

The Asimov-style psychohistorians might disagree. ;)
http://www.psychohistory.org

Ed