Kalpana one

why would it have to be attached. a mirror of that size could focus
the light in to a receptor at the center of one end. light pipes are
basically glass tubes (several different methods of doing this) that
carry the light along the path you chose. if the mirror is frequency
specific to the visible light spectrum (meaning it only reflects
those frequency, and appears to be clear glass to all others), it
would not increase the heat of the station. the most likely method of
doing this is to have bundles of fiber-optics that can be split up
to send each fiber to its proper destination. when it arrives it
enters a different type tube, one that radiates the light outwards
though out its length. or it can exist the fiber in a point light
source style, similar to light bulbs.

one advantage of this system is that the light can be turned on and
off with easy, simply by blocking one end or the other. or it can be
redirected in to another area for its uses.

another advantage is that glass blocks ultraviolet radiation,
something that has been found to be detrimental to both animals and
plants. plants that are raised under sunlight with the ultraviolet
radiation block are bigger and less bitter than normal ones.

another advantage is that it requires little structure, being mostly
plastic.

--- In spacesettlers@yahoogroups.com, Al Globus wrote:
>
> The primary reason light pipes were not used on Kalpana One is
because none
> of us were familiar with the technology.
>
> Here's a quick analysis:
>
> Kalpana One agriculture assumes 50m^2 per person for high intensity
> agriculture (continuous sunlight, optimal atmosphere, etc.). For
5,000
> people that works out to 250,000m^2 of plants. Assuming you need
full
> sunlight (probably right within a factor of 2), this means
250,000m^2 of
> collection -- or a square 500 m on a side.
>
> Kalpana One's thermal design requires that the axis of the cylinder
be
> aligned with the solar system's north-south axis. Furthermore, the
hull
> exterior rotates at 2 rpm.
>
> I don't know how one could attach a 500m on-a-side solar collector,
or even
> something half that size, to Kalpana One and keep it pointed at the
sun.
>
> Anyone else have a good idea?
>
> At 06:46 PM 4/27/2006, you wrote:
> >I couldn't find a publication date on this. Does anyone know?
> >We might invite the writers of the paper here to discuss it and
answer
> >our questions.
> >
> >Ralph wrote
> > >>... its a shame to use artificial light for crop raising when
> > >>theres so much natural sunlight. Agricultural is by far you
> > >>main power requirement. A way around this is to attach solar
> > >>collectors to the outside of the colony's hull and divert the
> > >>sunlight into the agricultural areas with fiber optics.
> >
> >It does seem strange to allow sunlight into the habitable areas,
but
> >use artificial light for agronomy. I wonder why was this was
chosen?
> >Also, I can't see how sunlight enters the habitable area; From the
> >endcaps which are parallel to the sunlight's incoming direction,
with
> >no mirrors?
> > With no light pipes or directed lighting, we must assume that all
> >lighting in the inner low-G decks is artificial. Again, with light
> >pipes, sunlight can be brought in anywhere, with no moving parts.
> >It'd be interesting to see a study of the relative mass and cost of
> >conventional electric lighting and light pipes for different
> >applications.
> >
> >Al Globus wrote:
> > > The exterior of the hull is rotating at 2rmp, giving you 1g
> > >away from the colony. Of course, as you move away from the
> > >hull the force becomes greater.
> >
> >Understood. Was this intended to rebut Ralph's suggestion for
exterior
> >light collectors? Sure, they'd be under outward pull, but they
could be
> >much smaller than the huge "petals" of O'Neill's Island 3.
> > One reason the Kalpana 1 designers might not like it is the need
to
> >turn them away from the light-pipe inlets. Another suggestion
comes to
> >mind: swing them only a bit so they direct light onto PV arrays
instead