Elon Musk's company was poised Wednesday afternoon (May 27) to launch Demo-2, a crucial test mission that will send NASA astronauts Bob Behnken and Doug Hurley to the International Space Station (ISS) aboard a Crew Dragon capsule. But the weather didn't cooperate, forcing SpaceX to cancel Crew Dragon's planned liftoff atop a Falcon 9 rocket with less than 20 minutes left in the countdown.

The next available launch opportunity doesn't come until Saturday, at 3:22 p.m. EDT (1922 GMT). That's when the space station will be in the desired place relative to NASA's Kennedy Space Center in Florida, Demo-2's launch site, explained Hans Koenigsmann, SpaceX's vice president of mission assurance.

Full coverage: SpaceX's historic Demo-2 astronaut launch explained

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