"Harry Andreas" wrote in message
...
In article , "Paul Austin"
wrote:

"The Enlightenment" wrote

"Paul Austin" wrote

"Henry J. Cobb" wrote
There will be a B3 manned heavy bomber.
There's this problem. Nanotube-stiffened composites have
a_long_way to
go before anyone would use them for primary structure. The
nanotubes
themselves are gleams in folks eyes and based on carbon fiber
composite experience, there will be a fairly long learning
experience
before they are ready for prime time.

last time I heard just plain (not even woven) nanotube was
$2300/gram.

choke and I thought space-grade stuff was expensive. The price
will
come down as we learn to make them in industrial quantities but I
still don't see a pressing need to substantially lighter primary
structure in a bomb-truck.

It's only money for fuel and range limitations.

The lighter you can make the primary structure, the less power
it takes to fly your weapons. Better fuel fraction, less fuel used,
less $$, better range.

That's true but... Tell me again how a lighter weight airframe is
going to deliver more_military utility_than you can currently buy with
a B-2. Spirits are already miracles of load-carrying effciency and
with the advent of the Small Diameter Bomb, it's difficult to see how
a larger payload will be much more useful.

As far as "less fuel used, less $$, better range" is concerned, fuel
cost is a tiny fraction of the life cycle cost of a heavy and as for
range, B-2s are already flying missions that strain crew endurance.

Substantially lighter airframes are going to be_very_expensive to
develop. You have to balance those costs against marginal improvements
in fuel consumption (since you aren't going to build a single-engined
heavy bomber).