Mission controllers for Inspiration4 have updated the launch window for SpaceX’s next crewed mission to Earth orbit, launching from Florida’s Kennedy Space Center.

A new five-hour launch window begins at 8:02 p.m. ET on Wednesday, according to a statement. The window is based on an updated weather forecast for the launch site and possible landing locations off the Florida coasts. The forecast calls for a 70 percent chance of favorable weather conditions for liftoff.

Here are five things you need to know about Inspiration4, which is billed as the first space mission completely crewed by civilians.