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Seattle-based Spaceflight Industries has purchased a SpaceX Falcon 9 rocket for launch in 2017 with a mash-up of satellites in the first such commercial arrangement for a rideshare mission on a U.S. launcher, the company announced Wednesday.

A commercial Falcon 9 rocket in the final stages of launch preparations fired its nine Merlin main engines Saturday at Vandenberg Air Force Base in California, verifying its readiness for liftoff with a Taiwanese Earth-imaging payload Thursday.

SpaceX is counting down to liftoff Saturday of a Falcon 9 rocket with a commercial cargo craft heading for the International Space Station after engineers replaced a component in an upper stage steering system that grounded the launcher Tuesday.