I
imagine taking off from an airport
runway flying at three to five times the
speed of sound at altitudes of 20 miles
or even higher a few short hours after
departure you come to a stop halfway
around the world or maybe you took off
from a runway and flew directly into
orbit to work in space and then you
returned landing on a conventional
Airport runway the National aerospace
plane will try to make both scenarios a
reality NASA and the Department of
Defense have done research on hyper
sonic technology for many years the NASA
technology demonstrator will be a highly
advanced explain a new member of the
elite special research aircraft that
includes the x1 which in 1947 was the
first aircraft to break the speed of
sound and fly supersonic in the early
1960s the x-15 became one of the first
manned hypersonic aircraft and reached
speeds of Mach 7 or about 4,500 miles
per hour one of the key technological
developments of the x30 or NASA are in
the propulsion area an air-breathing
hydrogen-fueled supersonic combustion
ramjet engine or scramjet engine is now
being developed for speeds from about
Mach 7 to Mach 25 the engine uses the
velocity of the vehicle to compress air
as it is rammed into the intake this
compressed air is then mixed with
gaseous hydrogen at this stage to
generate high thrust a development on
which we will focus is materials here to
speak on that is Matt MELAS with the
advent of the aerospace plane there's
become a need for a lot of new material
development beyond a shadow of a doubt
we need new materials alright and these
new materials will most probably be
composite materials but instead of using
on
metal matrix based composite will be
using our epoxy based will be using a
metal matrix based composite all right
metal matrix being copper for instance
one of the big problems NASA is facing
with the advent of the National
aerospace plane deals with not only
finding the right materials to use but
in cooling them as well we have to
figure out some way of making a very
strong material that's going to survive
in a high temperature environment and
what we're going to have to do is
actively cool this material alright by
putting some kind of a cryogenic fluid
behind a gaseous hydrogen or liquid
hydrogen which is very cold and acts as
a good heat transfer medium to take heat
away from the leading edge so on on one
side of the of the material on the
inside of the wing for instance there'll
be a lot of coolant rushing through to
cool the inside down and on the outside
you'll have a very hot surface and that
is why we need to high heat conductivity
for instance you look at fighter jets
that's travel mock water Mach 2 or even
the Concorde which goes oh come on to
you see the three wins are very narrow
okay and there's a problem with that
because the smaller the leading edge
gets the more difficult it is to cool
and the hotter it gets because it's such
a small it's just such a small point
lying out there in the free stream that
it gets very warm very quickly the
national aerospace plane is one of the
projects being developed by NASA for
future space use but we cannot expect it
to do all of our work in space the
national aerospace plane being something
that will possibly be able to supplement
the shuttle fleet or maybe even replace
it but obviously if you have an airplane
that can take off from a runway and go
to orbit with some people in it and go
to the space station for instance or
something like that obviously it would
be capable of shuttle type operations as
far as payload goes I think moving big
things like space station components or
say for instance they want to go to Mars
and they have to get some big boosters
up there or something like that I don't
see the National aerospace plane taking
that kind of payload up there the
National aerospace plane is expected to
yield a high payoff for the United
States in the early 21st century with
reduced space launch costs vastly
reduced transit time on long-haul air
routes major investments by private
enterprise in commercial space ventures
and sustained us preeminence in
aeronautics with all of the social and
economic benefits that accompany it