Carrying 5,000 pounds of supplies and scientific equipment, the Cygnus cargo craft and the Antares rocket it was riding exploded just after launch this evening.

The unmanned Orbital Science Corp.'s spacecraft had just lifted off to start its third re-supply mission to the International Space Station when it paused, began to fall and then exploded at NASA's Wallops Flight Facility in Virginia.

No one was hurt in the accident and all personnel -- from both NASA and Orbital Science -- in the area have been accounted for, NASA reported.

The rocket, which launched at 6:22 p.m. EDT, suffered a catastrophic anomaly seconds after liftoff, according to the space agency. The Orbital Science team reportedly did not note any problems before the crash.

NASA planned to hold a news conference to go over the details of the crash later tonight.

"It is far too early to know the details of what happened," Frank Culbertson, Orbital's executive vice president, said in a written statement. "As we begin to gather information, our primary concern lies with the ongoing safety and security of those involved in our response and recovery operations."

The Orbital Sciences team is in the process of executing its contingency procedures, securing the site and data, including all telemetry from the Antares launch vehicle and Cygnus spacecraft.

The cargo craft was carrying crew provisions, spare parts and scientific experiments.

It was originally scheduled to launch on Monday, but that launch was scrubbed because a boat was in a restricted zone near the launch area.

NASA has contracted with Orbital Science to provide five more resupply missions after this one.

Today's accident comes just days after the SpaceX Dragon cargo craft returned to Earth. On Saturday, the spacecraft left the space station and landed safely in the Pacific Ocean, wrapping up its fourth contracted cargo resupply mission to the orbiting station.

SpaceX has a contract to make eight more resupply trips to the station.

Since NASA retired its fleet of space shuttles in 2011, the space agency has been relying on commercial companies to ferry supplies to the space station.