Watch conditions at Kennedy Space Center during Tropical Storm Isaias

Axiom Space, a Houston-based company with plans to develop a commercial outpost in space, announced Thursday it has signed a contract with SpaceX to ferry a professional astronaut and three paying passengers to the International Space Station as soon as next year on the first fully private human spaceflight mission to Earth orbit.

SpaceX’s next Falcon 9 rocket is being readied for liftoff Aug. 14 on a space station resupply run. The two-stage rocket completed a hold-down engine firing Thursday at launch pad 39A at NASA’s Kennedy Space Center in Florida.

Set to resume a brisk pace of launch activity after a nearly six-week respite, SpaceX test-fired its next Falcon 9 rocket Thursday at NASA’s Kennedy Space Center in Florida ahead of a planned liftoff Monday with several tons of experiments and supplies for the International Space Station.