Tensegrity Structuspace habitats

Stephen D. Covey

While Ive historically been a reflected sunlight fan, Ill have to admit you make some valid points.

But I think you go slightly too far when you say,
farmed

with natural sunlight beamed from above in a way that simulates the movement of the Sun from dawn to dusk
. Nobody has proposed a rising/setting sun for the agricultural tori of the 70s designs. Even Gerard ONeill said that an ear of corn could care less about considerations like the shape of the sun in the sky.

I think this issue turns on expense. If technology advances to a point that 1 square mile of densely-packed LEDs costs no more than 1 square mile of windows and another of Mylar mirror, then maybe. But while Im sure future technological advancement will make 1 square mile of LEDs cost dramatically less than same would cost if manufactured today, I still cant see it costing the same or less than the original windows/mirrors.

When were making something by the square mile, wed better go with the least-costly alternative.

Regards,
Mike Combs

From:
spacesettlers@yahoogroups.com [mailto:spacesettlers@yahoogroups.com]
Sent:
Saturday, March 14, 2015 5:10 AM
To:
spacesettlers@yahoogroups.com
Subject:
[spacesettlers] Re: Tensegrity Structure space habitats

Agreed. Of course, Ive been arguing for LEDs for a long time, partly for thermal reasons (you produce a lot less waste heat if crops are grown using only photosynthetically active wavelengths, mostly deep red and blue), and partly for the thermal reason that natural sunlight is mostly waste heat, anyway, that youll just need to disipate. White light is only needed for people and parks a fraction of the total floor space.

The chevron and mirror systems needed to direct sunlight around the shield mass, not to mention the control systems to simulate a normal day-night cycle, take space, and mass, and add a lot of complexity.

Besides, I like the relative simplicity of having a solar panel array between the habitat and the sun to gather sol! ar energy while shading the habitat so it can more easily radiate the heat of agriculture and civilization.

Of course, with my approach, agriculture is done in separate areas than human live/work/recreation, so having different lights isnt a problem (and note that being able to have different crops have different day/night cycles can be an advantage). No, I dont believe that we should build huge habitats where a huge portion of our interior surface is farmed using current terrestrial practices of tractors and plows, with natural sunlight beamed from above in a way that simulates the movement of the Sun from dawn to dusk.

I detail my arguments in
http://ramblingsonthefutureofhumanity.blogspot.com/2009/11/lightin! g-our-space-habitats.html

Stephen D. Covey