BFS drops composite construction

I saw a report today that SpaceX was dropping composites for tanks and
main structure on BFS in favor of using "heavy metal" (Musk's phrase).
It's unclear why the change, although it's probably a cost/schedule
move. It's also unclear if this change is permanent or if it's only
for early ships. Also unclear what impact this will have on payload,
since BFR will now be lifting a much heavier BFS than was originally
planned.

All these changes are both bad and good. They're bad because of
impacts to weight and such. They're probably good in that they
indicate that we're close to actual development and that is driving
changes.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw