What Happens If Russia Shuts The Door On Their Leaky ISS Module?
NASA astronauts recently prepared for an emergency return to Earth after Roscosmos cosmonauts began unauthorized drilling in the International Space Station’s (ISS) Zvezda module to repair air leaks. According to reports, the two agencies are now considering sealing off the Zvezda Transfer Chamber (PrK) permanently to stop atmospheric loss as the station enters its final years of operation.
Why did NASA order astronauts to prepare for an emergency return?
NASA directed its crew to secure themselves inside the Dragon capsule and prepare for a potential departure earlier this month. This order came while Russian cosmonauts performed impromptu demolition work on the Zvezda module, a core component of the ISS in orbit since 2000.
Roscosmos authorized its crew to drill and cut into the module walls to locate and fix persistent air leaks. NASA personnel objected to the procedure. The Russians eventually abandoned the plan, and NASA crews resumed normal duties, though the exact nature of the communications between the two agencies remains undisclosed.
Where is the ISS leak located and what is causing it?
The leak is located in the Transfer Chamber, known as the PrK, at the aft end of the Zvezda module. Since 2019, the station has experienced a steady loss of atmosphere from this area.
Cracks in the PrK walls allow air to vent into the surrounding unpressurized equipment bay. According to technical descriptions of the leak, the external hull of the module has not been breached. While the station’s life support systems currently compensate for the loss, a sudden increase in the leak rate could threaten the pressure vessel’s structural integrity.
What happens if the Zvezda Transfer Chamber is sealed?
Anonymous sources indicate Russia may abandon repair attempts and permanently seal the crippled compartment. This would stop the air leak but would force the crew to abandon the docking port on the other side of the PrK hatch.
Losing one docking port is manageable because the Russian segment has multiple alternative ports for crew and cargo. Furthermore, the port can still support the transfer of liquids and gases. Plumbing for water, oxygen, and propellants from Progress resupply ships runs on the outside of the structure and connects automatically, requiring no crew access to the PrK interior.
| Operational Status | Crew/Cargo Access | Fluid/Gas Transfer |
|---|---|---|
| Hatch Open (Pre-2024) | Full Access | Full Access |
| Hatch Closed (Intermittent) | Limited Access | Full Access |
| Permanently Sealed (Proposed) | No Access | Full Access |
How will the ISS maintain its orbit without the Zvezda rear port?
The station requires periodic “reboost” maneuvers to counteract atmospheric drag and prevent it from falling back to Earth. Normally, a Progress spacecraft docked at the Zvezda rear port provides the necessary thrust along the station’s center line.
Some analysts believe the repeated stress of these reboosts may have caused the cracks in the PrK. If NASA and Roscosmos determine that pushing the station’s mass through this weakened structure is unsafe, they must shift reboost operations to the U.S. side.
A modified Cargo Dragon has already demonstrated the ability to perform this role by carrying additional propellant, a capability similar to the Space Shuttle’s operations prior to 2011.
FAQ: The Future of the Zvezda Module
Is the International Space Station in danger of collapsing?
While a structural failure of the pressure vessel is an existential threat, the current leak is contained within the PrK and has not breached the external hull.
Can the ISS operate without Russian docking ports?
The station can survive the loss of one port, as multiple other docking options exist for crew and cargo transfers.
Why not just fix the leak permanently?
The risks associated with drilling into a pressurized module in space—as seen during the recent tension between NASA and Roscosmos—often outweigh the benefits for a station nearing the end of its lifespan.
What do you think about the decision to seal off parts of the ISS rather than risk dangerous repairs? Let us know in the comments or subscribe to our newsletter for more updates on orbital infrastructure.