SpaceX and NASA’s historic Crew Dragon launch has been postponed due to poor weather conditions.

The launch, which was scheduled to take place at 1:33 p.m. PT on Wednesday at the Kennedy Space Center, was scrapped due to stormy conditions over Florida. Weather conditions were poor throughout the day and authorities had hoped the weather would have cleared by launch.

But the levels of electrical discharge in the air remained too high for a safe launch. At 17 minutes before the scheduled takeoff, SpaceX personnel made the decision to scrap the launch due to the weather.

There are a number of weather rules that must be met in order for a launch to go ahead. At the scheduled time of the launch, three of these rules were violated, including one by the presence of natural lightning in the area. Unfortunately, the weather issues would likely have cleared within 10 minutes if the launch could have been delayed.

It was not possible to delay the launch, as it was what is called an “instantaneous launch,” in which the launch must go ahead at the exact scheduled time or it cannot go ahead at all. This is due to the orbital dynamics of how a craft reaches the International Space Station (ISS). In order to approach the ISS from the northeast, as is advised, the timing required the spacecraft to be launched at exactly 1:33 p.m. PT or not at all.

A new date for the launch has been scheduled for 12:22 p.m. PT on Saturday, May 30. This is slightly earlier in the day, and will also be an instantaneous launch.

Astronauts Bob Behnken and Doug Hurley were professional and courteous as ever, and when informed their mission would be delayed, they thanked the ground team for their efforts and assured them that compared to the complexities of organizing a launch, “we’ve got the easy job.”

The much-anticipated launch would have marked the first astronaut launch from U.S. soil since the space shuttle program ended in 2011, as well as the first time an astronaut crew was ferried into space aboard a private rocket.

The Weather Channel reported mostly favorable weather near the launch site early on Wednesday, and NASA administrator Jim Bridenstine said the agency was “go for launch” as of Wednesday morning. But NASA had to take into account weather near the launchpad and farther downrange, in case of an emergency that forced the astronauts to abort the launch midflight.