Air-breathing hypersonic engines

On Tuesday, May 27, 2003, at 03:45 PM, Ian Woollard wrote:

> Scramjets seem to be mostly interesting to the military- they want to
> go
> places really quickly, outrace all the missiles etc. etc. But getting
> to
> orbit? It might make a good first stage, but you're still going to need
> rockets either in the first stage (in which case the scramjet has added
> quite a bit to your first stage's orbital weight), or as a second (in
> which case you've spent lots of money to create a not very special
> first
> stage).
>

Obviously a scramjet by itself can't get you to orbit, at the very
minimum you need a rocket for the circularization burn. However, by
radically reducing the wet weight of a first stage they could make a
major contribution. For example, if my a calculation I did a couple
years ago is correct, it's interesting to note that on the shuttle the
solids are there mostly to lift themselves and the oxygen.

The materials in one asteroid (the largest ) are sufficient to make
orbital space colonies with ~500 times the surface area of the Earth in
usable real estate. See http://lifesci3.arc.nasa.gov/SpaceSettlement/
for details.

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
position of any organization I'm familiar with.