The last private trip to the space station has been postponed indefinitely due to a leak in the Russian module.

The launch of the AX-4 mission to the International Space Station (ISS) has been indefinitely delayed. The flight, the fourth private flight by Axiom Space, founded by Spanish-born former NASA astronaut Michael López-Alegría , was scheduled to begin on June 11; however, a leak in the booster of the Falcon 9 rocket that was to lift SpaceX's Crew Dragon spacecraft, carrying four astronauts, aborted the takeoff.

While awaiting a new date, Russian cosmonauts detected a "new pressure signature" (a new leak in an area where others had already been detected since 2019) in the Zvezda service module, on the Russian side of the orbital laboratory. As NASA explained in a statement, the astronauts "sealed some additional areas of concern and measured the current leak rate. Following this effort, the segment is now holding pressure," the statement said.

"The crew onboard the International Space Station is conducting normal and safe operations," NASA spokeswoman Cheryl Warner said in a statement to Space.com . "We are evaluating this latest update and will provide additional information as it becomes available."

Still, the agency and Axiom Space have decided that canceling the mission for now is the most prudent course of action. This "gives NASA and Roscosmos additional time to assess the situation and determine if any additional troubleshooting is necessary," NASA wrote in the latest update. No new planned launch date has been announced yet.

As its name suggests, AX-4 will be Axiom's fourth crewed mission to the ISS—two of which were crewed by López-Alegría himself . The approximately two-week flight will be commanded by former NASA astronaut Peggy Whitson, who is currently Axiom's director of human spaceflight.

The other three crew members are Indian pilot Shubhanshu Shukla, Polish mission specialist Sławosz Uznański-Wiśniewski, and Hungarian mission specialist Tibor Kapu. No one from India, Poland, or Hungary has ever visited the ISS, so this trio will make history when the AX-4 finally lifts off from the launch pad.