“ Public doesn't understand the difference between getting to space and getting to orbit. It's important to make that distinction.
To do a suborbital flight, you need a terminal velocity of around Mach 3. To get to orbit, you need a terminal velocity of Mach 25.
Orbital is 625 units of energy. Only about 1.5% of the energy of orbit is required to get to sub orbit.”
— Elon Musk