ISS On-Orbit Status 9/13/04 -- . Update on Elektron: The Elektron O2
generator is still Off. After the replacement of the gas analyzer for
hydrogen (H2) in the O2 line by Padalka last Friday (9/10), the machine ran
for about an hour and then shut down again. Moscow subsequently diagnosed
the culprit to be a pressure increase in the hydrogen (H2) line due to
cross-sectional constriction caused by deposits of KOH (potassium hydroxide)
crystals. Because of the manifolds' design this also rises the gas pressure
in the O2 supply line, and its increase automatically shuts down the
generator. A similar situation was encountered on the space station Mir. The
crew's extensive efforts today focused on cleaning out the deposits from the
H2 line and, after that apparently didn't suffice, replaced a pressure
regulator valve. The Elektron was turned on afterwards for some time and was
then shut off for the night, but it is too early to tell whether it is
actually restored.