Preparations continued on May 22 for the first crewed US space flight since 2011.SpaceX, the first of NASAs commercial flight partners, tested the Falcon 9 rockets engines on that date with a static fire at the Kennedy Space Center in Florida.The rocket is set to launch on May 27, carrying two US astronauts to the International Space Station.A day earlier the rocket was rolled out to the launch pad, as seen in this video. Credit: NASA Commercial Crew via Storyful