I think I'm going to try covering the top and bottom of the orbiter with 1/64 plywood instead of cardstock or 1/32 balsa. Much tougher than either material, yet almost as light. Finishing 1/64 ply takes much fewer filler coats of dope than balsa so the weight is probably total same. Using Monokote covering would be even lighter, but that stuff is awful for painting details on. Paint adhesion on Monokote sucks.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !