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Air leak continues despite repairs on Zvezda module of ISS

According to a report today in the Russian press, the air in the Zvezda module of ISS continued to leak away slowly during a test, following this week’s repair of two cracks in the module’s hull.

At about 07:00 GMT on Saturday, ISS cosmonaut Sergei Ryzhikov told a specialist at the Mission Control Center, located near Moscow, that the pressure in the intermediate chamber of the Zvezda module was 678 millimetres of mercury. The pressure stood at 730 millimetres of mercury on Friday evening, right after the hatch of the compartment was closed. Thus, the pressure in the chamber decreased by 52 millimetres of mercury over 11.5 hours.

Based on the thorough nature of the two repairs, this leak must be coming from another very tiny leak that has not yet been detected. Though the leak is very slow and thus not an immediate threat to the astronauts on board, it suggests once again that the leaks are coming from stress fractures resulting from Zvezda’s 20-plus years in orbit. If so, the problem is very serious indeed. Zvezda is the central module for ISS. Replacing it will not be simple or easy.

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From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

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  • pawn

    I hope someone on the ground is taking this seriously. I’m no expert but an increasing leak rate may be the result of a propagating stress fracture. Given the criticality of the module, what if any analysis has been done or is in work to quantify the risk of a catastrophic failure.

  • Lee Stevenson

    @pawn…. Hopefully greater minds than ours are on the case! I’m sure I’m not alone in having quality tools, both forged and cast which supplied excellent service for multiple decades until they failed catastrophically and splintered into bits…. The point you bring up is worrying indeed!

  • Scott M.

    @pawn, I’m also adding on and hoping that you’re wrong. Not as a personal attack on you, but more because IF (and that’s a heavy IF) the ISS has such a catastrophic failure it’ll be a huge black eye for manned spaceflight as a whole.

  • Ray Van Dune

    OT – I predict that the modified nose cone recently observed for SN-15 is to accommodate a remotely-triggered connect / disconnect mechanism between this StarShip and the Bluto / Tankzilla crane, replacing the “Squid”.

    In addition to the fact that man-lifts that can reach the top of an SH/SS stack are insane, if not impossible, there is the fact that using a person in a man-lift to reconnect the crane to the tip of an unstable landed SS (like SN-10) is foolhardy. I was relieved when SN-10 blew up, and I’ll bet some folks at SpaceX were too!

  • George C

    What is the chance that the Russians are just trying to keep this old girl flying long enough for China to launch its station? Then they leave the rest of the ISS owners with a big repair bill. Given the limited lufetime, the recent rental price hikes by NASA would make a lot of sense. Think real estate hardball. Time to read the fine print.

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