Live coverage: International crew lands in Kazakhstan

SpaceX called off a Falcon 9 countdown Wednesday due to the threat of lightning from thunderstorms along Florida’s Space Coast, pushing back the departure of a cargo mission for the International Space Station until Thursday.

A Falcon 9 rocket lifted off from Vandenberg Air Force Base at 4:39 a.m. PDT (7:39 a.m. EDT; 1139 GMT) Wednesday, and SpaceX successfully landed the rocket’s first stage on a drone ship in the Pacific Ocean. The mission’s primary objective is the deployment of 10 Iridium Next communications satellites into low Earth orbit.

Russia is delaying the return to Earth of three space station crew members by about a month in the wake of the failure of a Russian Progress supply ship that spun out of control moments after reaching orbit April 28. Launch of three fresh crew members also will be delayed, from May 26 to late July.