For years, Sir Richard Branson’s Virgin Galactic has been trying to invent a better way to launch rockets into space. Instead of launching from Earth in a fiery blast and a cloud of dust, Virgin Galactic aims to carry a “SpaceShipTwo” spaceship into the stratosphere, strapped to the belly of a “WhiteKnightTwo” mothership — then detach the former from the latter, and rocket to 62 miles above sea level.