[extropy-chat] Space elevator numbers V

[Keith Henson]

At 06:38 PM 2/16/2007 -0500, Keith wrote:

snip


>A 0.2 mm by 1.5 m by 1 km roll of Invar weights close to 2.5 metric
>tons.  Punched out holes will reduce the weight to a ton.  After passing
>through a roll former you get a beam with the cross section of a bracket
>character.  Why Invar?  Think eclipses.

BTW, this much Invar at 60 10,000 ton power sats per year uses up about 15% 
of the world production of nickle.

Of course after a few years I rather expect nickle from asteroids to start 
coming on the market.

Keith