SpaceX sent its towering Starship rocket on a dramatic test run that ended with a controlled, fiery splashdown in the Indian Ocean, giving the company a largely successful outing for the latest version of its giant spacecraft. The mission was not flawless, but the snags did little to dampen the mood. On the company livestream, SpaceX staff erupted in cheers after a flight seen as an important step forward as Elon Musk's company moves toward what could be a record-setting initial public offering. The huge rocket lifted off…