This is an issue, sort of, that was raised as we pondered things in this thread.
The design of the US space shuttles is more than 25 years old at this point. It seems reasonable to conclude that eventually, perhaps soon, America will need to replace them. When that occurs, it seems likely that a new design will be needed in order to better take into account any technological advances made since the last design.
The current shuttle design is very practical, but it doesn’t offer a lot of defense. A small piece of tile taken out while the craft is in orbit, a missle to the nose during a descent, or any number of small incidents could be (and have been) fatal to the crew on board.
In light of the United States’ recent awakenings concerning terrorism, would it make sense to design any new spacecraft with armor of some kind, in the hope that it would be able to withstand a direct SAM hit (or any type of missle, debris, etc.). Could we do it? What would the costs be in additional fuel needed to lift the presumably greater mass into orbit, and would those costs be self-justifying?
Or should we continue to build light-frame craft, and just hope that no one shoots at the shuttle?
My $.02: I think we could probably come up with a new design that was more along the lines of the stratosphere craft like SpaceShipOne that was both more maneuverable and better armored than the shuttles. I also think that with new materials technology and new weapons technology, we could make a craft with some serious offensive capabilites as well. I also think that it makes sense to do this, and even do this now, while we still have such a huge jump on the field compared to the rest of the world. It would offer the US a terrific advantage not just in military terms, but would make us the first truly space-faring people on this planet (or off of it, if you’d rather).