SpaceShipOne landed safely Wednesday after blasting off up into space in what appeared to be the successful start to its bid to win a $10 million prize for private spaceflight. Officials on the ground said the ship had unofficially cleared the 100-kilometer mark, crossing the internationally accepted boundary of outer space. That came after tense moments immediately after the plane’s separation from its carrier aircraft. As SpaceShipOne’s rocket engine completed its 90-second burn, the plane went into a severe roll upwards. Stunning images showed the plane corkscrewing in as many as 10 revolutions per minute, before pilot Mike Melvill brought it back under control.