NASA has indefinitely postponed a four-person crew's mission to the International Space Station (ISS) on June 12 due to ongoing investigations into air leaks in the Russian segment of the orbiting laboratory.

The US space agency is collaborating with Roscosmos, Russia's space agency, to analyze a new pressure signature detected by cosmonauts in the Zvezda Service Module, a core compartment that has been experiencing small leaks for months.

Recent inspections and repairs by cosmonauts have helped to stabilize the pressure in the module, although the exact leak rate has not been disclosed by NASA.

The decision to delay the private astronaut mission is a result of the ageing ISS, with small cracks appearing in recent years, especially in the Russian segment. These issues have led to plans to retire the ISS by 2030.

While the air leaks have not posed immediate safety risks to the astronauts on board, they serve as concerning indications of the station's deteriorating condition. NASA and Roscosmos have been working to address these leaks by having crew members apply temporary fixes such as tape and glue.