Air-breathing hypersonic engines

On Monday, May 19, 2003, at 09:07 PM, Ian Woollard wrote:

> It's not nearly as simple as that though- the thrust to weight ratio of
> scramjets is a lot less than a rocket (rockets often manage 100:1 or
> better, scramjets would be lucky to get 20:1,

Is this dry weight thrust to weight? Most rockets have only a few
percent payload because they have to lift all the fuel, and all the
fuel to lift that fuel, and so on.

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 should
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 insure life would survive a planetary catastrophe.

Al Globus
CSC at NASA Ames Research Center
http://www.nas.nasa.gov/~globus/home.html

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