NASA is cautiously optimistic about launching Axiom Space’s fourth private mission, Ax-4, to the International Space Station (ISS) this week. This development follows a recent postponement prompted by concerns over an air leak in the station’s Russian segment. However, new data suggests that recent repair attempts on the aging orbital outpost may be proving successful, making the Axiom Mission 4 launch and ISS air leak status a critical point of focus for the space agency.
Ax-4 Launch Delayed by Zvezda Module Pressure Concerns
Last week, NASA abruptly postponed the Axiom Mission 4, originally scheduled for June 11. The delay was attributed to a new pressure signal detected in a segment of the Zvezda service module. This particular module has been the source of a very slow air leak for nearly six years, presenting an ongoing maintenance challenge for the International Space Station. The Zvezda module, a critical component of the Russian segment, provides life support and habitation for crew members.
Interpreting the Latest Pressure Signals
In a follow-up statement released on Saturday, NASA elaborated on the ambiguous nature of the new pressure signal. This change in airflow or cabin pressure, picked up by sensors, could indicate that the persistent small leaks have finally been sealed. However, there’s also a possibility that air has simply begun flowing to a different area within the aft segment of the Russian module, which would account for the altered readings.
“Following the most-recent repair, pressure in the transfer tunnel has been stable. Previously, pressure in this area would have dropped,” NASA stated. “This could indicate the small leaks have been sealed. Teams are also considering the stable pressure could be the result of a small amount of air flowing into the transfer tunnel across the hatch seal from the main part of [the] space station.” NASA continues to monitor these pressure changes closely to ascertain the true condition.
NASA Sets New Target for Ax-4 Liftoff
While evaluating the condition of the transfer tunnel and the hatch seal between the main space station and the rear of the Zvezda module, NASA has decided to proceed with targeting the launch of Ax-4 no earlier than Thursday, June 19. The decision to initially postpone the mission was made to allow NASA and the Russian space agency, Roscosmos, more time to evaluate the situation aboard the ISS and determine if further troubleshooting was necessary before adding more crew. NASA’s latest update confirmed that “teams are making progress evaluating the transfer tunnel configuration.”
The Ax-4 mission will be commanded by spaceflight veteran Peggy Whitson, a former NASA astronaut renowned for holding the U.S. record for the most cumulative days in space. She will be joined by pilot Shubhanshu Shukla from India, and mission specialists Sławosz Uznański-Wiśniewski from Poland and Tibor Kapu from Hungary.
The Persistent Challenge of the ISS Air Leak
Roscosmos first officially reported the air leak in August 2020, tracing its origin to the Zvezda life support module, which was launched to low Earth orbit in July 2000. Since that initial report, the rate at which air is escaping from the Zvezda service module has concerningly doubled, increasing from approximately one pound per day to just over two pounds per day, according to a report from early 2024. This escalation led NASA to elevate the leak to its highest level of risk. Historically, there were reports that NASA and Roscosmos faced challenges in agreeing on the root cause of the leak or a unified strategy to permanently fix it.
Conclusion
The recent repair efforts offer a glimmer of hope for addressing the long-standing air leak issue within the Zvezda module of the International Space Station. While NASA is proceeding with plans for the Axiom Mission 4 launch, the overall fitness of the aging ISS to safely accommodate additional astronauts remains under careful and continuous evaluation. The integrity of the space station is paramount for crew safety and ongoing scientific research. MaagX will continue to monitor this developing story and provide updates on the Axiom Mission 4 launch and the ISS.
