Despite permanent repair of crack, air still leaking from Zvezda
According to a Russian news report yesterday, air is still leaking from the Zvezda module of ISS, despite the permanent repair of the crack earlier this week.
Earlier, the crew locked the hatches into the intermediate chamber. The Mission Control asked whether the crew had measured the pressure before the hatch into that chamber was opened. The crew reported that the pressure went down considerably in the smaller part of the compartment while it remained isolated from the rest of the station by an airtight hatch. “The pressure in the intermediate chamber went down from 723 mm of the mercury column to 685 millimeters,” Ryzhikov said.
The report is poorly written, and is unclear on the exact date this air test was done. It is therefore possible the test was done prior to the permanent repair.
If however the air is still leaking, this suggests there might be more than one leak point in that part of Zvezda. According to this same story, the two Russian astronauts during their spacewalk on November 18th took pictures of the exterior area of Zvezda where the leak is located, and noted no exterior damage.
All these facts point to a very serious problem. If there was no exterior damage, it means the leak was probably not caused by a micrometeorite hit (though closer more extensive observations as well as a review of the photos might still conclude otherwise). The fact that the leak is continuing after the permanent repair suggests there is another leak, in the same part of Zvezda. That section is also a docking port, and would have experienced the most stress during the several dozen dockings that have occurred since Zvezda was launched in 2000.
These facts therefore suggest stress damage and aging as the cause, which means the problem will only get worse no matter what method is used to seal any future leaks.
One quick solution that would work, at least for awhile, would be to close the hatch on this intermediate chamber, and do no more dockings to it. This at least would seal the station from atmosphere loss, and reduce the stress on this section of Zvezda. Whether Progress freighters, which use this port, can use another port, or will have a more limited ability to dock, is not clear, however.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
According to a Russian news report yesterday, air is still leaking from the Zvezda module of ISS, despite the permanent repair of the crack earlier this week.
Earlier, the crew locked the hatches into the intermediate chamber. The Mission Control asked whether the crew had measured the pressure before the hatch into that chamber was opened. The crew reported that the pressure went down considerably in the smaller part of the compartment while it remained isolated from the rest of the station by an airtight hatch. “The pressure in the intermediate chamber went down from 723 mm of the mercury column to 685 millimeters,” Ryzhikov said.
The report is poorly written, and is unclear on the exact date this air test was done. It is therefore possible the test was done prior to the permanent repair.
If however the air is still leaking, this suggests there might be more than one leak point in that part of Zvezda. According to this same story, the two Russian astronauts during their spacewalk on November 18th took pictures of the exterior area of Zvezda where the leak is located, and noted no exterior damage.
All these facts point to a very serious problem. If there was no exterior damage, it means the leak was probably not caused by a micrometeorite hit (though closer more extensive observations as well as a review of the photos might still conclude otherwise). The fact that the leak is continuing after the permanent repair suggests there is another leak, in the same part of Zvezda. That section is also a docking port, and would have experienced the most stress during the several dozen dockings that have occurred since Zvezda was launched in 2000.
These facts therefore suggest stress damage and aging as the cause, which means the problem will only get worse no matter what method is used to seal any future leaks.
One quick solution that would work, at least for awhile, would be to close the hatch on this intermediate chamber, and do no more dockings to it. This at least would seal the station from atmosphere loss, and reduce the stress on this section of Zvezda. Whether Progress freighters, which use this port, can use another port, or will have a more limited ability to dock, is not clear, however.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The problem with locking out that compartment (and the article is unclear) is it depends on exactly what is the intermediate compartment.
The ball at the end of Zvezda has 4 openings. One into Zvezda itself, one to Zarya. Then one pointing up (Poisk docked to it, Soyuz/Progress dock to that) and Pirs pointing down (Soyuz/Progress dock to it).
So are they closing both hatches in Zarya and Zvezda? Isolating the ‘ball’? If so, they are cut off from docking ports. on the aft, and Pirs/Poisk. Cut of from Zvezda/Zarya on either side. I guess they could keep it closed, let the pressure in a small space drop, then refill, when they need to pass through/use it.
Soyuz and Progress can use use any of the 4 available ports. (Aft of Zvezda, where ATV could dock (Soyuz/Progress, but ATV could only use aft port). Rassvet on the other end of Zarya could still be used for Soyuz.
As noted, this is pretty bad if it is stress/structural.
Typo alert:
Zvezda was launched in 2000 not 2020.
Mitch S: Thank you. Typo fixed.
I seem to remember that when ISS was being built and carrled into orbit piecemeal via rocket launches and the space shuttle, the Americans and Europeans waited years for the Russiians to get their act together enough to build the modules that they were to contribute. Some said at the time that we would be time and money ahead to just go.ahead and build their sections for them. But no, for political reasons it was decided to let them build part of ISS no matter how long it took them.
Perhaps we are now seeing the downside of having parts of ISS built by a country that was not as far along as us in quality control, while being pressured and rushed to get it finished ASAP. Perhaps corners were cut, or perhaps quality assurance took a back seat. Repeated docking stress or not, one would think that those modules would have purposely been overbuilt to an extent that would allow for the stresses of numerous dockings for the life of the station without compromising structural integrity.
Did they turn back all the external insulation and photograph the area or just take a few picts or the insulation to see if it had holes in it.
Did we just wait a month for a spacewalk that could have been done weeks ago?
I don’t see this as a Russian issue but a man in space issue. We have been living in a near vacuum on the ISS now for only a few decades. Hardware ages, things will break and fail. Bad design and engineering will be exposed. Each incident is a learning opportunity on survival in space. The ISS has been sited as a laboratory for experiments in the weightlessness environment of space. Yes! But the station itself is an experiment as well on how man can live in space.
It’s time to replace the darn thing with something, say, 9m in diameter (before inflation), weighing up to 100 tons per segment, and located in a low-inclination orbit. Somebody should at least start doing some conceptual work on that.