I'm reading alot about the new falcon 9 rocket. Burning tons of rocket fuel in order to lift an object straight up at a 90 degree angle is still the way to go apparently? We have planes that can reach the edge of space. What is holding us back from creating a vessel that has the ability to take off just as say an SR71, reach a super high altitude off normal flight, and then engage some sort of booster to finish the job from the edge of our atmosphere? It seems like this would be a lot more cost effective when it comes to fuel.