A rocket carrying a private unmanned spacecraft loaded with supplies for the International Space Station exploded shortly after launch on Tuesday. Orbital Science’s Antares rocket, carrying the company’s Cygnus spacecraft, exploded a few seconds after liftoff Tuesday evening from NASA’s Wallops Flight Facility on Wallops Island, Virginia.

NASA’s launch director confirmed on NASA’s livestream that all personnel were accounted for and no one was injured. The cause of the accident was not immediately known. It came after a “flawless countdown” during which “the team was not tracking any issues,” NASA added.

The launch happened at 6:22 p.m. ET, but the rocket “suffered a catastrophic anomaly” a short distance above the platform, then fell and exploded on contact with the ground.

“Parts were sent flying everywhere, and then the vehicle fell back to the pad, exploding in an even larger fireball, setting the entire area on fire,” Robert Pearlman, editor of the space history news website collectSPACE.com, who witnessed the launch, told Space.com.

The rocket launch was to be Orbital Sciences’ third official cargo mission to the Space Station for NASA under a $1.9 billion contract, which calls for a total of eight delivery missions. The robotic Cygnus spacecraft — also built by Orbital — was filled with 5,000 pounds of food, water, experiments and other gear for the astronauts currently living aboard the space station.

The ISS won’t go hungry, though: NASA spokesman Rob Navias told the AP that nothing urgently needed was lost, and that the Russian Space Agency is scheduled to send up supplies in a separate launch Wednesday.

Also aboard the craft, according to the launch director, was some “classified crypto equipment,” likely for secure communications, which the ground crews were instructed to prioritize.

An accident investigation team is being formed from NASA and Orbital personnel.

—NBC News Staff