NASA has indefinitely postponed a four-person crew's mission to the International Space Station following an investigation into air leaks on the Russian segment of the orbiting laboratory.

The U.S. 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 over 20 years old that has been experiencing small leaks for months.

Cosmonauts on the space station recently conducted inspections of the module's interior surfaces, sealed additional areas, and measured the current leak rate. Following these efforts, the segment is now maintaining pressure. However, NASA did not disclose the specific leak rate.

Over the years, small cracks on the ISS, especially on the aging Russian segment, have led to the decision to retire the ISS by 2030. While the air leaks have not posed immediate safety risks to the astronauts on board, they are concerning signs of aging that NASA and Roscosmos have been addressing by having crew members patch the leaks with various solutions.

Shubhanshu Shukla, an Indian Air Force pilot selected by the Indian Space Research Organization for India's debut crewed mission, the Gaganyaan mission in 2027, is scheduled to be part of the Axiom Mission 4. At 39 years old, Shukla will be the first astronaut from India's astronaut corps to visit the ISS.