Gallery: Antares rocket explodes

A commercial Northrop Grumman Cygnus supply ship berthed at the International Space Station fired its main engine for 50 seconds Tuesday in a test of the spacecraft’s ability to reboost, and possibly eventually deorbit, the massive research outpost.

The two structural elements of Orbital ATK’s OA-7 Cygnus space freighter were delivered to Kennedy Space Center for final assembly, the packing of cargo and launch to the International Space Station.

Look back on the launch Saturday of a Northrop Grumman Antares rocket from Wallops Island, Virginia, powered by a pair of kerosene-fueled RD-181 engines producing 864,000 pounds of thrust.