money is in short supply

On Feb 25, 2011, at 9:46 PM, Frank wrote:

> The sail foils used for the SSPS-spacecraft would just feature a
> mass of 32 kilograms.
> Not so much, to give up the advantage of better production capacity
> on Earth to save
> a part of this 32 kg.

Where does this figure come from? Including thin-film solar cells I
calculate that a system based on the Ikaros satellite would probably
weigh around 45 g/m^2 for the energy production alone. See http://space.alglobus.net/papers/SSI2010SSPpaper.pdf
for details.

The dinosaurs were destroyed by an asteroid because they weren't space-
faring. It's almost as if Gaia then thought "Well, dinosaurs worked
pretty well, but space-faring is necessary. Maybe I'll try mammals
this time." Humanity is now developing systems to detect and deflect
asteroids, and could build orbital space colonies to spread beyond
Earth to ensure life would survive a planetary catastrophe.

Al Globus
http://alglobus.net

Views expressed in this email are only my opinions and are not the
position of any organization I'm familiar with.