Orbital Sciences Corp.'s Antares rocket, which was going to carry almost 5,000 pounds of supplies to the International Space Station (ISS), exploded shortly after takeoff at 6:22 p.m. EDT on Tuesday, Oct. 28.

NASA will hold a press conference at 9 p.m. and plans to provide updates as they become available.

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

There have not been any reported injuries, and all employees of the Wallops Flight Facility (where the rocket launched) are accounted for and safe. There had not been any detected issues with Antares before the launch.

The mission would have been the first to use the CASTOR 30XL second stage motor, which is larger and more powerful than most models; it also would have carried the heaviest load ever delivered to the ISS by Orbital. The mission would have been the third one Orbital took to the ISS.

The cargo aboard the ship was mainly scientific investigations, such as one that tests pea shoot growth in space, and another that would have looked at how blood flows in environments outside of Earth. Cygnus was also set to deliver 1,649 pounds of crew supplies such as food and flight procedure books; 1,404.3 pounds of vehicle hardware; 145.5 pounds of spacewalk equipment; and 81.6 pounds of computer resources.

The Antares rocket was 131.5 feet tall and boasted an impressive liquid-fueled first stage powered by two Aerojet Rocketdyne AJ26 engines and a solid motor ATK CASTOR 30XL to throw it into orbit. Its powered launch sequence would have last for about nine-and-a-half minutes from liftoff.

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