Air-breathing hypersonic engines

On Friday, May 23, 2003, at 08:47 PM, Ian Woollard wrote:

>>
>> Is this dry weight thrust to weight?
>>
> Yes. The weight of the engine alone (although including the
> turbopumps),
> no tanks or payload or anything, compared to its thrust. Jets mostly
> get
> more like 5:1. A 15:1 jet would be big news.
>
> The NK-39 achieves 130:1 (uses Kero). The Shuttle only manages 70:1,
> (uses hydrogen)
>

Using dry weight to thrust ignores the main advantage of a scramjet --
it doesn't carry the oxydizer. A more meaningful measure is wet weight
to thrust.

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

Views expressed in this email are only my opinions and are not the
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