An unmanned NASA rocket exploded during launch from Wallops Island, Va., late Tuesday afternoon. The Antares rocket was scheduled to take supplies to the International Space Station.

The rocket also carried a science project from Knox County students at L & N STEM Academy. The project was set to test what effect gravity has on fecal matter.

“There has been a vehicle anomaly,” Orbital Sciences, the contractor supplying the rocket, said on its Twitter feed.

It had originally been slated for takeoff on Monday night but the mission was scrubbed. The launch was to have begun a fourth space station delivery for the Virginia-based Orbital Sciences.

The Antares rocket was scheduled to launch at 6:22 p.m. The rocket was intended to propel the Cygnus vehicle, packed with 5,050 pounds of cargo, to rendezvous with the International Space Station.

The company says no one was believed to be hurt and the damage appeared to be limited to the facilities.

Flames could be seen shooting into the sky as the sun set.

The Cygnus cargo ship was loaded with 5,000 pounds of gear for the six people living on the space station. It was the fourth Cygnus bound for the orbiting lab; the first flew just over a year ago.

NASA is paying the Virginia-based Orbital Sciences and the California-based SpaceX company to keep the space station stocked in the post-shuttle era. This is the first disaster in that effort.