Disaster as ISS bound rocket explodes

Washington - An unmanned Antares rocket exploded seconds after liftoff from a commercial launch pad in Virginia on Tuesday, marking the first accident since Nasa turned to private operators to deliver cargo to the International Space Station.

The 14-storey rocket, built and launched by Orbital Sciences, blasted off its seaside launch pad at the Wallops Flight Facility at 18:22 EDT or 22:22 GMT, carrying a Cygnus cargo ship bound for the space station. It burst into flames moments later, then plunged to the ground in a huge ball of fire and smoke, but authorities said no one was hurt.

The six crew members in orbit aboard the space station - two Nasa astronauts, one from the European Space Agency and three Russian cosmonauts - watched the launch via a Nasa TV feed, said Mike Suffredini, the space station program manager.

"They were disappointed... of course they are well aware that they have plenty of resources on orbit," Suffredini told reporters during a conference call.

With a Russian cargo ship due to reach the space station on Wednesday, just 14 hours after the explosion in Virginia, the loss of the Cygnus vessel posed no immediate problem for the orbiting team.

"There was no cargo that was absolutely critical" aboard Cygnus, Nasa Associate Administrator William Gerstenmaier said. Suffredini added that the crew has enough food and other supplies aboard to last four to six months.

'Shook the whole building'

Orbital Sciences stock fell 15.5% to a two-month low of $25.65 in after-hours trading.

The cause of the mishap was under investigation, said Frank Culbertson, Orbital Sciences executive vice president.

Footage of Tuesday's launch showed the Antares rising slowly into the night sky as flames suddenly engulfed the rocket, from the bottom to the top about 11 seconds after liftoff, before the vehicle sank back downward in a conflagration.

Ronda Miller, manager of the Ocean Deli in Wallops Island, Virginia, said she felt the force of the blast from the eatery, about 8km from the launch pad.

"We were standing outside waiting for it to launch and we saw bright red, and then we saw a big black cloud, and it shook the whole building where we work," Miller said. "And then I came back in to work and seen fire trucks going every which way."

Nasa said no one was in the vicinity of the explosion, and Orbital Sciences said in a statement: "We've confirmed that all personnel have been accounted for. We have no injuries in the operation today."

The spacecraft was carrying "some classified cryptographic equipment, so we do need to maintain the area around the debris in a secure manner," said Mike Pinkston, the company's Antares program manager.

The National Security Agency had no immediate comment on the classified equipment reported to be aboard the cargo ship.

Nasa officials said damage on the ground appeared limited to the Virginia-owned launch facility, but its full extent was not immediately known. The rocket itself and the cargo ship it carried were valued at $200 million, Culbertson said.

This online video shows how the explosion happened.