SpaceX launched four private astronauts en route to the International Space Station, including the first woman from Saudi Arabia to travel to space.

The crew lifted off atop a Falcon 9 rocket Sunday evening from the Kennedy Space Center in Florida. The mission, operated by Axiom Space Inc., is the second of four human spaceflight launches that SpaceX is set to handle for the company.

With plans to build its own private space station in the future, Axiom is conducting the series of crewed flights to the ISS to prepare for sending people to its own orbiting vehicle. Axiom and SpaceX, the Elon Musk-run company known formally as Space Exploration Technologies Corp., sent the first all-private crew to the ISS in April 2022.

The latest mission, called Ax-2, is commanded by Peggy Whitson, a former NASA astronaut and now the director for human spaceflight at Axiom. Joining her are two mission specialists from Saudi Arabia: fighter pilot Ali Alqarni and biomedical researcher Rayyanah Barnawi.

John Shoffner, a car racing enthusiast who made money through the fiber optic telecommunications industry, is the mission’s pilot. Shoffner paid an undisclosed sum to fly on this mission. One seat on a SpaceX Crew Dragon spacecraft is estimated to run about $55 million, according to NASA’s Inspector General.

The crew is slated to dock with the ISS Monday and spend eight days living and working on the station. They are set to do more than 20 experiments while on board, before returning to Earth.

The next mission, Ax-3, is expected to launch no earlier than November. Axiom Space is also building its first habitable space module.