How, if at all, does suborbital flight benefit real space flight outside of the atmosphere? I mean suborbital flights as a business on its own, e.g. for tourism, not just suborbital testing of space equipment.
Historically, military applications like the V2 and ICBM's were very helpful for space flight, which I think can even be said became a spin off from such suborbital projects. But what about today's suborbital projects? Virgin Galactic, Lynx, Skylon, Copenhagen Suborbital and others all seem to be very aerodynamical with little in common with space flight. (With the exception of Blue origin which seems conceptually easier to scale into real space travel, and of course JPaerospace fantastic idea about "airship to orbit" which however remains to be proven.)
Could there for example be an orbital and then a lunar upgrade of the VG SpaceShip Two? Doesn't look so superficially. If a suborbital company of today decides to go into space instead, do they have competence and experience required thanks to their suborbital RnD? Or do suborbital flights have more in common with airplanes than with spaceships?