[log in to unmask] wrote:
>
> Nick writes:
>
> > It kind of boggles my mind with our advances in technology there are no
> >  foreseeable successors to the Concorde.  Wouldn't a 400 passenger SST
> >  that could make four round trips a day between America and Europe be
> >  economically viable?
>
> The environmental problems associated with high-altitude flight are not to be
> minimized. There is already a great deal of accumulated evidence that current
> tropospheric flight traffic is significantly increasing the cloudiness at
> that level, and thus not insignificantly modifying the weather (see, e.g.,
>
>      http://hyperion.gsfc.nasa.gov/AEAP/98minnisabs.html
>      http://asterix.essc.psu.edu/fieldcamp/success/success1.html )
>
> The problems of hypersonic flight at very high altitude (upper stratosphere)
> are much worse, which is highly chemically photoreactive. For a reasonable
> review (written 30 years ago) of the problems, see:
>
>      http://www.magma.ca/~jdreid/uv.htm
>
> The few Concorde flights a day that are now conducted can be tolerated. Heavy
> SST/HST traffic probably can't be.
>
Food for thought.  It seems more research is needed.  One questions "Can
alternative energy technologies solve the problem?'

Nick D.