>Why is it important to note that it was not orbital? Orbital is what actually provides any significant economic value. But the nature of the Rocket Equation,

>Why is it important to note that it was not orbital? Orbital is what actually provides any significant economic value. But the nature of the Rocket Equation, effects with atmosphere, and how those interact with the limits of our material science means that there is an absolutely enormous gulf between a sounding rocket and getting to orbital velocity and back again. All of that is what makes it so hard but it's also required to be of any real practical use. So the DC-X was a noteworthy historical milestone/demo and test bed but going from there to something like the Falcon 9 let alone Starship takes an tremendous amount of further innovation and engineering (and investment of course). The new engine work alone SpaceX has done is a hufe deal and is what defines the envelope for the rest of the system.