Video: Antares rocket explodes

The first sign of failure during the doomed launch of an Orbital Sciences Corp. Antares rocket from Virginia came from the rocket’s first stage about 15 seconds after liftoff.

An upgraded Castor 30XL upper stage motor will provide the Antares rocket with an extra boost during launch with supplies and experiments for the International Space Station, a critical upgrade Orbital Sciences says will ensure it meets contractual cargo delivery requirements.

With investigators zeroing in on a decades-old rocket engine as the cause of a catastrophic launch mishap, Orbital Sciences officials said the company plans to use other launchers to send cargo to the International Space Station while modifying its Antares rocket with a new propulsion system.