Video: SpaceX Dragon departs space station

SpaceX is more than a week into a company-led probe of a launch pad explosion Sept. 1 that destroyed a Falcon 9 booster and an Israeli communications satellite, but the investigation so far has turned up no smoking gun on the cause of the mishap, Elon Musk said Friday.

A Northrop Grumman Antares rocket and Cygnus cargo carrier climbed into orbit Saturday from Wallops Island, Virginia, in pursuit of the International Space Station with more than 7,200 pounds of research hardware and provisions, the second supply ship launch to the space station in less than 24 hours.

In a significant milestone preparing for liftoff of the world’s most powerful rocket, SpaceX test-fired 31 of the booster’s 33 methane-fueled engines Thursday in South Texas as the company eyes a launch attempt as soon as March.