re: Suborbital spaceflight - a dead end?
The market will determine the faith of suborbital flight. You have to ask who is going to buy a successful orbitor? Private sector? NASA? Military?
Mark Oakley comment;
The routine commercial use of suborbital vehicles would in turn contribute to the development of orbital vehicles by maturing the technologies needed for such vehicles and by creating the infrastructure needed to build and support them.
Some key words there.
SteveS