A NASA television broadcast showed an unmanned private spacecraft exploding on October 28, six seconds after launch on a resupply mission to the International Space Station (ISS).
NASA mission control in Houston said the accident occurred just after Orbital's unmanned "Cygnus" cargo ship blasted off toward ISS carrying 2,200 kilograms of supplies for the six astronauts living at the research outpost.
Fires were seen burning at the coastal launch pad after the Antares rocket blasted off from Wallops Island, in the eastern U.S. state of Virginia.
It was unclear what caused the explosion.
The mission was to be private company Orbital Sciences Corporation's fourth trip to the ISS.