Jeff Findley wrote:
False, especailly for an expendable SSTO. An expendable SSTO isn't all that
hard to do, it's just that no one has tried. The "performance uber alles"
philosophy of your typical aerospace engineer makes them *really* want to
drop some of the heavy bits on the way up, even if it adds complexity and
cost to the design because they always think that the performance gained is
worth the added cost.


You can see the germ of Atlas in North Amercian Aviation's HATV design
from 1946: http://history.nasa.gov/SP-4202/p1-10.jpg
You can just see an engineer looking at that, and thinking: "Now , if we
could jettison the eight small motors once a lot of the fuel was burnt..."

Pat