(video)Billion Dollar Nasa rocket explodes six seconds after lift-off

An unmanned Nasa rocket carrying supplies to the International Space Station exploded seconds after lift-off from a commercial launch pad in Virginia.The Orbital Sciences Corp Antares rocket exploded mid-air just seven seconds after launch at 6.35pm local time on Tuesday. The cause of the accident was not immediately known.The rocket blasted into the air before combusting in a massive orange fireball and smashing back into the ground."We have lost the Orb-3 vehicle," said the commentator on Nasa television, after the lift-off at the Mid-Atlantic Regional Spaceport, Wallops Island, Virginia."At this point it appears that the damage is limited to the facility," the Nasa commentator said.