A mission by private space company Axiom Space taking the first woman from Saudi Arabia to space is set to launch on Sunday from Florida at 5.37 pm EDT.
The ticket-holding crew was launched by SpaceX under the command of a retired NASA astronaut who is now employed with the organisation that organised the trip. A businessman from the United States who now runs a sports car racing team has also joined.
The four should launch Monday morning for the space station, where they will stay just over a week before landing safely on Earth off the coast of Florida.
They are the first citizens of their nation to launch on a rocket since a Saudi prince took off in 1985 aboard the space shuttle Discovery. By chance, a United Arab Emirates astronaut will meet them when they arrive at the station.