After reading this forum and the t/space website, I can't figure what the mass of the rocket would be. Will the second stage be orbited as well or will it immediately return back to Earth (I wonder about this because of the amount of fuel needed in the CXV to reach the ISS and to slow down for de-orbit)?
Also, the rocket won't have wings (unlike airlaunched Pegasus, SpaceShip One and X15). This is supposed to save weight but wouldn't wings increase drag and thus the carrier could lift a heavier rocket? The Shuttle on top of the B747 (I've read) is no problem thanks to its own wings.

And at ignition (after release from the carrier), astronauts would go from 0 G to 3 G's at once, without transition! How can one train to go through it?

Raoul