Soyuz TMA lifetime

i'm not entirely sure what supplies bound the Soyuz TMA lifetime,
other than the container used for the toilet gets filled after 4 days
use. Other than the toilet, most other systems on TMA are similar to
those used for the multi-week missions back in Soviet times. As late
as Soyuz T-13, Soyuzes were used to support crews for more than a
week.



"Jorge R. Frank" wrote in message ...


Hmm? Both the TM and the TMA only have a four day "free-flight" capability.
An extended mission at a mini-station would either require the station to
provide life support so that the Soyuz can power down like it does at ISS,
or upgrades need to be made to the Soyuz to allow it to fly longer.

In article ,
Explorer8939 wrote:
i'm not entirely sure what supplies bound the Soyuz TMA lifetime,
other than the container used for the toilet gets filled after 4 days
use. Other than the toilet, most other systems on TMA are similar to
those used for the multi-week missions back in Soviet times. As late
as Soyuz T-13, Soyuzes were used to support crews for more than a
week.

I'd assume it's a simple consumables issue, but I don't know. Jim?

(There is a hardware constraint to the total lifetime, which is why
Soyuz get exchanged by taxi flights - seals (in the fuel lines?)
degrade, and can't be totally trusted after about six to eight months -
but I'm not aware of any similar ones which would only be relevant when
powered on. The LEM had something similar; once it was fuelled, it had
to be used within a set timeframe lest the fuel lines corrode)

--
-Andrew Gray