[sarex] ISS STATUS REPORT #04-2

[Arthur Z Rowe <n1orc@xxxxxxxxxxxx>]

    Submitted by Arthur - N1ORC

    International Space Station Status Report #04-2
    5:30 p.m. CST Friday, January 9, 2004
    Expedition 8 Crew
    Expedition 8 Commander Mike Foale celebrated his 47th birthday on
    Wednesday this week while Flight Engineer Alexander Kaleri observed
    the Russian Orthodox Christmas on Thursday as they both continued
    research work, performed several maintenance activities and
    conducted troubleshooting efforts to assist ground engineers
    analyzing a small decay in the Station cabin’s atmospheric pressure.
    The pressure decay poses no threat to the crew's safety or to the
    continued operation of the Station and its systems, but Russian and
    U.S. engineers are conducting a thorough investigation of the
    decrease, which appears to have begun about Dec. 22. The decline
    occurs at a rate so small, only a few hundredths of a pound per
    square inch (psi) of pressure per day, that it is difficult to detect.
    This week, Foale and Kaleri checked a variety of valves and seals
    throughout the Station using an ultrasonic leak detection system and
    found no leaks. Today, Kaleri checked a Russian system, called
    Vozdukh, that removes carbon dioxide from the cabin as well as
    several other Russian systems for leaks and found none.
    To continue the effort to diagnose the source of the pressure decay,
    flight controllers in Russia and the U.S. plan to ask the crew to
    shut off portions of the Station periodically in coming days. In the
    next few days, hatches will be closed for periods ranging between
    12-24 hours to seal off various modules to check if any element
    within them could be the source of a leak. Those modules may include
    the Progress cargo vehicle, the Pirs Docking Compartment and Soyuz
    spacecraft, and the Quest airlock.
    If those steps do not detect the source of the leak, then the crew
    may be asked to move into the Russian living quarters module for
    several days and shut hatches separating the Russian living quarters
    and other modules from the rest of the station for several days.
    Those actions would likely not take place any earlier than
    Wednesday. Engineers are continuing to work on potential plans for
    those steps to diagnose the leak and to review the number of hatches
    that would be closed at that time.
    The decay in pressure over the past few weeks aboard the station has
    amounted to a decrease from the normal pressure of 14.7 psi, a
    pressure equivalent to sea level on Earth, to a pressure today of
    about 14 psi, a pressure equivalent to the normal air pressure in
    Oklahoma City. The changes in pressure do not present a concern for
    the health of the crew. Also, plentiful supplies of air, oxygen and
    nitrogen, are aboard the station -- enough that the current rate of
    decay could be sustained for six months without further supplies
    aboard if required. However, engineers are confident they will
    identify and correct the source of the decay as they continue the
    diagnostic work onboard.
    Flight controllers may feed more nitrogen into the Station
    atmosphere late Sunday or Monday to increase the overall air
    pressure and maintain the cabin atmosphere in the optimal range for
    the operation of equipment aboard the complex. Russian flight
    controllers also are continuing to evaluate the possible replacement
    of parts of the Station's oxygen-generating Elektron system. The
    Russian system generates oxygen by recycling wastewater aboard the
    complex. It has failed, but spare parts are aboard that engineers
    are confident can bring it back to full operation and they are
    developing plans to perform that work possibly next week. While the
    Elektron failure is being evaluated, the crew has used Solid Fuel
    Oxygen Generators, canisters that are heated to produce oxygen, to
    replenish oxygen on the Station.
    Despite the leak detection activities, engineers are not certain the
    fluctuation and slight decline in pressure aboard the Station is the
    result of a leak from the complex. Evaluations continue to determine
    if it instead could result from or be significantly contributed to
    by troubleshooting and intermittent Elektron operation, SFOG oxygen
    generation activities, recent changes in temperature and sun angles,
    the accuracy of various pressure measuring systems, or other factors.
    Information on the crew's activities aboard the Space Station,
    future launch dates, as well as Station sighting opportunities from
    anywhere on the Earth, is available on the Internet at:
    http://spaceflight.nasa.gov/
    Details on Station science operations can be found on an Internet
    site administered by the Payload Operations Center at NASA's
    Marshall Space Flight Center in Huntsville, Ala., at:
    http://scipoc.msfc.nasa.gov/
    The next ISS status report will next week as events warrant.
    -end-


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