Digest Number 1341

> Message 7
> From: "Al Globus" aglobus@...
> Date: Fri Apr 28, 2006 11:14am(PDT)
> Subject: Re: Kalpana one
>
> 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.

The habitat has that much area effectively facing the sun at any one time.
So cover the exterior
with multiple colectors. Have a look at the website they are not very heavy.
Use
lots of them and direct the light into the interior agricultural area with
fiber optics.

The technology was developed by one of the US national labs. Perhaps the
Kalpana
people can contact someone there to discuss how feasible the idea is.

ta

Ralph