Tag: air leaks

NASA/Axiom announce another four-day launch delay for Axiom’s fourth manned mission

8:55 am

NASA and Axiom today announced that they have rescheduled the launch of Axiom’s fourth manned mission to ISS, dubbed Ax-4, to June 22, 2025 in order to give Russian and American engineers more time to assess the leak repairs in the station’s Russian Zvezda module.

The press announcement provided little information, simply stating that:

The change in a targeted launch date provides NASA time to continue evaluating space station operations after recent repair work in the aft (back) most segment of the International Space Station’s Zvezda service module.

It would be nice if the agency would release some actual data. Earlier reports had suggested that the repairs had completely sealed the leaks and that the station was no longer losing air. The vagueness of today’s report suggests that the repairs might not have been as successful as hoped. It could also be engineers simply want more data for a longer period to prove the repairs have worked.

The lack of detailed information causes unnecessary speculation.

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Axiom manned mission delayed further because of new Zvezda leaks on ISS

8:58 am

Figure 3 from September Inspector General report
Figure 3 from September Inspector General report, showing Zvezda’s location on ISS.

According to a press update today by NASA, the launch of the commercial Ax-4 manned mission to ISS has been further delayed due to work by the Russians attempting to seal new leaks in the station’s Zvezda module.

NASA and Axiom Space are postponing the launch of Axiom Mission 4 to the International Space Station. As part of an ongoing investigation, NASA is working with Roscosmos to understand a new pressure signature, after the recent post-repair effort in the aft most segment of the International Space Station’s Zvezda service module.

Cosmonauts aboard the space station recently performed inspections of the pressurized module’s interior surfaces, sealed some additional areas of interest, and measured the current leak rate. Following this effort, the segment now is holding pressure.

In other words, the Russians had recently detected an increase in leakage in the module, identified several more cracks inside Zvezda, and have been working to seal them.

The graphic above comes from a 2024 NASA inspector general report, which at that time noted a significant increase in the leak rate in 2024 (see the data in the lower right). Since then it has been NASA policy to close the hatch that connects the American and Russian sections of the station whenever anything docks with Zvezda, due to risk that the docking could cause the module to fail entirely.

Zvezda is one of the oldest modules on ISS, built in the late 1980s and launched in 2000. It is believed the leaks are due to stress fractures in its hull due to the many dockings and undockings that have occurred at its aft docking port.

If the NASA press release can be believed, the situation is under control and the repairs have been successful. If so, expect the Axiom mission to be rescheduled shortly.

If not, we could be witnessing the beginning of the end of ISS, five years earlier than planned by bureaucrats in Washington and Moscow.

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Roscosmos will launch unmanned Soyuz to ISS on February 21

5:15 pm

Roscosmos today announced that it will launch the unmanned Soyuz to ISS on February 21st, only a two-day delay after doing a quick inspection of its outer surface for possible damage following the coolant leak of a Progress freighter on February 11th.

BtB’s stringer Jay provided me this translation of the announcement at the link:

The Soyuz MS-23 spacecraft has been checked and is beginning to be prepared for launch. The preparations suspended the day before at Baikonur will resume tomorrow or the day after tomorrow.
The launch is scheduled for the 20th of February.

The ship was inspected. No maliciously drilled holes were found. We decided not to wait any longer. In any case, a refueled ship must either be launched or sent to a museum.

Update: removal of the launch vehicle to the launch pad on February 18, launch on February 21″ [emphasis mine]

The highlighted words are truly intriguing. It appears Roscosmos is desperately trying to convince the world that the repeated recent leaks to Soyuz and Progress spacecraft are not related to sabotage on the ground. At the same, Roscosmos has never told us the results of its investigation into the 2018 hole in a Soyuz capsule that someone drilled and then patched before launch. It seems incredibly unlikely that the two recent leaks in the exterior coolant systems of two different spacecrafts were both caused by impact from a micrometeorite or tiny piece of space junk. Two such impacts could of course occur this frequently, but for both to happen to such similar locations on only Russian spacecraft seems beyond improbable.

Either way, the decision makes some sense. The available lifeboats on ISS right now are really insufficient. Better to get this launched. More important, they had already begun fueling it, and once that is done the clock was running. They have to launch by a certain time.

Meanwhile it would be wise for NASA to begin arranging new emergency lifeboat arrangements with SpaceX as well as Boeing (once it finally gets Starliner operational). Depending on the Russians for even part of this responsibility seems ill advised. If preplanned properly, SpaceX could certainly launch one of its Dragon manned capsules quickly in an emergency.

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More leaks found in Russian Zvezda module on ISS

10:34 am

Earlier this week Russian astronauts located and patched three more leaks in the 20+ year old Russian Zvezda module on ISS.

Prior to this week’s discovery, the recent patching done by Russian astronauts had reduced the air loss by about half. They need to do another seal test of Zvezda to see if these newer patches have reduced it further.

The report at the link from Russia is as usual very vague. No photos of any of the leaks have been released, by either Russia or NASA. No cause either has been described. This lack of information suggests that the leaks represent a more systemic problem, possibly related to stress fractures from age and wear. If so, it also suggests that Zvezda is nearing its pull-date. How this central module will be replaced from the station remains a major mystery.

Above all, this puts some urgency to the launch of newer modules, such as those being built by the private company Axiom.

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Russia: Air leaks fixed on Zvezda

9:30 am

According to the Russian state-run press, Russian astronauts have completed their repair work on the ISS module Zvezda and are about to seal the module to test their work.

“The crew of the International Space Station has completed the repair and recovery work on the hull of the Zvezda module. In the coming days, Sergei Ryzhikov and Sergei Kud-Sverchkov will close the hatches in the Zvezda module to check the atmospheric level,” the press office said.

Previous reports suggested the astronauts had located a total of two cracks, both now sealed.

The larger question however remains. Are the cracks stress fractures, and if so do they suggest that Zvezda’s 20-year-old hull is beginning to fail? The Russians have been very silent about these questions, though they have admitted the possibility once or twice, almost as an aside.

Nor has NASA been forthcoming. The American space agency has apparently joined the Russians in keeping this problem out of the news, at all costs. Once, the employees at NASA were Americans who demanded openness from Russia and from themselves. No more. Increasingly our government workers are indistinguishable from Soviet apparatchiks, whose main goal was to protect the government from bad press.

If Zvezda’s hull is failing then ISS faces some very serious engineering issues. They can be solved, but not by silence and sticking one’s head in the sand.

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Russian astronauts begin work to seal 2nd Zvezda leak on ISS

9:27 am

After successfully sealing the largest crack on the twenty-year-old Zvezda module on ISS, Russian astronauts have now begun work on sealing a second such crack.

The report, from Russia’s state-run news service TASS, is not very informative. It does not report the size of the leaks, their nature, and any other important conclusions the Russians have gathered about Zvezda’s overall condition and future, based on these cracks.

Nor has state-run NASA been very transparent on this subject, releasing little further information. The silence from these government entities about the cracks is very worrisome, as it suggests these fixes are merely bandaids on a more serious issue with Zvezda’s structure, and our dishonest and bureaucratic governments do not wish to reveal this fact to the public.

I hope I am wrong, but suspect I am not. If Russia follows its pattern for the past half century, they will provide a more detailed report only after the problem has been completely solved. If these patches are merely temporary fixes over a more serious problem, don’t expect that detailed report for some time.

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