Cargo spaceship explodes on takeoff

An unmanned cargo ship bound for the International Space Station exploded six seconds after liftoff tonight in the first major disaster to strike the commercial space effort.

The Antares rocket, owned by Orbital Sciences, was carrying 5,000 pounds of experiments and equipment for the six astronauts aboard the station. A NASA spokesman said none of the items were vital to the crew.

The explosion sent flames shooting into the sky above Virginia just as the sun was setting. No one was injured and all of the company’s personnel were accounted for.

“We will understand what happened—hopefully soon—and we’ll get things back on track,” Orbital Sciences’ executive vice president Frank Culbertson told his team an hour after the failure. “We’ve all seen this happen in our business before, and we’ve all seen the teams recover from this, and we will do the same.”

Orbital Sciences and California-based SpaceX have billions of dollars in U.S. government contracts to deliver cargo to the station. SpaceX is scheduled to carry astronauts into orbit as early as 2017.

The Associated Press contributed to this report.