NASA Eying June 19 for Earliest Launch Opportunity Of Axiom-4 Mission Amid Ongoing ISS Concerns

The delay, announced on June 12, came just as the mission team resolved technical issues with the launch vehicle and successfully completed a pre-launch test. However, NASA halted the countdown to further assess a "new pressure signature" in the PrK transfer tunnel, a component at the far end of Russia’s Zvezda Service Module that has suffered air leaks for several years.

The PrK tunnel has been the source of persistent air leakage since 2019, defying multiple repair attempts. Recent repairs, however, seem to have stabilized the situation, with NASA reporting that the tunnel is "now holding pressure." Yet, NASA remains cautious, suspecting that the apparent success may be due to a small amount of air inadvertently flowing into the tunnel from the main ISS module rather than a complete seal.

In a brief statement issued the evening of June 12, NASA reassured the public:

 “The crew aboard the International Space Station is safely conducting normal operations. We’re assessing this latest update and will provide additional information as available.”

On its ISS blog the next morning, the agency elaborated slightly, noting that it was still evaluating whether the pressure readings truly indicated that the leaks were sealed.

Technical Hurdles on Earth and in Orbit

Ax-4 is set to carry four private astronauts to the ISS for a 14-day mission aboard a SpaceX Crew Dragon capsule launched atop a Falcon 9 rocket. The mission had already faced two earlier delays—first due to unfavorable weather on June 10, and then again on June 11 due to a liquid oxygen (LOX) leak on the rocket, which was promptly repaired.

After successfully completing a wet dress rehearsal on June 12, SpaceX was ready to proceed. But just hours later, NASA unexpectedly postponed the mission again to allow further safety checks concerning the PrK tunnel.

Behind the Scenes: Budget Cuts and International Friction

The Ax-4 delay comes as the ISS faces growing scrutiny over its long-term viability, both technically and politically. The 420-metric-ton orbital laboratory, a U.S.-Russian joint venture, has been in continuous operation since 2000. While the U.S. and its partners—Canada, Japan, and 11 European nations—have committed to operations through 2030, Russia has only committed until 2028.

Technical experts from both countries remain at odds over the severity and root cause of the leaks in the Russian segment. Former astronaut Bob Cabana, now chair of the NASA ISS Advisory Committee, has reported differing levels of concern between the U.S. and Russian sides.

Compounding these issues is a looming $6 billion budget cut to NASA proposed by the Trump Administration in its FY2026 plan. The cut would reduce crew and cargo flights and limit ISS research to only what directly supports human exploration of the Moon and Mars. NASA's Dana Weigel, ISS Program Manager, has already indicated that budget constraints in FY2025 could force them to reduce crew sizes and scale back cargo missions.

Meanwhile, Elon Musk, CEO of SpaceX, has repeatedly raised concerns about the ISS's aging infrastructure, suggesting the station may need to be decommissioned earlier than 2030. This despite SpaceX's own financial interest in ISS operations—NASA recently awarded the company an $843 million contract to develop a U.S. Deorbit Vehicle (USDV) designed to safely guide the ISS into the Pacific Ocean by 2030.

In contrast, Senator Ted Cruz (R-TX) has proposed increasing NASA’s ISS funding, advocating an additional $1.25 billion for ISS operations and $325 million more for the USDV. Cruz argues that preserving American leadership in space, especially with China’s Tiangong-3 station already operational, is a matter of national interest.

Ax-4 is part of a larger NASA strategy to transition from the ISS to commercially operated space stations in the coming decade. Axiom Space, which is leading the Ax-4 mission, plans to attach its own module to the ISS in 2027—delayed from an original 2024 target—as part of its long-term goal of building an independent space station.

Other companies are racing ahead. Vast, for example, says its Haven-1 module will be the first private space station in orbit, launching in May 2026, albeit with limited capacity. Its multi-module follow-up, Haven-2, is planned for completion by 2032.

Both Axiom and Vast are relying heavily on SpaceX for launch, crew transportation, and communications via Starlink.

For now, the Ax-4 crew remains grounded, waiting for the green light from NASA. The agency has not yet confirmed a launch date but says June 19 is the earliest possible opportunity.

By Azhar