Possible ammonia leak inside the ISS - January 14th 2015

[Targeteer]

The Node 2 MDM with the failed card is still up but Houston fears that if it failed overnight the crew would lose airflow in Node 2. They would receive a caution to wake them up.

[SkipMorrow]

Samantha just posted another log book entry on G+.
https://plus.google.com/+SamanthaCristoforetti/posts/YRvtvYbKuUF

She said that when they went back into the USOS the second time,

Houston directed us to send two people forward to sample the atmosphere first and Butch decided that he and Terry, as the Soyuz right seaters, would go.

Ok, I know the right seat is the 2nd Flight Engineer. So why would it make sense to send the 2nd flight engineer to do the air tests?

[Space Pete]

If the MDM in question is the Node 2-2 MDM (the same one that was responsible for the original false ammonia alarm), then it is an internal MDM so it would not require an EVA to R&R it. Don't know whether a spare is available on-board, or whether the individual cards could be repaired/replaced.

[Targeteer]

I think I caught word that Houston power cycled the MDM to restore the misbehaving card. Terry did say he was going to say a prayer for the Node 2 MDM

[robertross]

I have a question. Where do we stand on NTA available volume?
It was noted they vented the Nitrogen from the system into space. How much margin is there left in the Nitrogen Tank Assembly on orbit before it requires a replacement?

(I know there's two pre-positioned spares on orbit):
http://forum.nasaspaceflight.com/index.php?topic=31826.msg1222357#msg1222357

[hop]

Ok, I know the right seat is the 2nd Flight Engineer. So why would it make sense to send the 2nd flight engineer to do the air tests?

If they were incapacitated, it would have the least impact on an evacuation. FE2 is the "tourist" seat.

[mtakala24]

aaand Loop B is alright now, even higher pressure than loop A. And PM is running.

[Targeteer]

CAPCOM confirmed during a lengthy and impromptu DPC that loop B is fully restored and that all systems are reintegrated.  Also discussed was a burning smell detected strongest in Node 3 this morning by the crew that failed to cause any alarms or sensor detections.  The crew was asked to perform one more combustion product (CSACP) test to verify no increased readings from the nearly zero readings this morning.  The ground is continuing to investigate the source of the smell described as either burning rubber or ash.  Normal operations were resumed once no conclusive indications of fire were detected.

[robertross]

Thanks for the great coverage on here guys; it was amazing.

[360-180]

Ok, I know the right seat is the 2nd Flight Engineer. So why would it make sense to send the 2nd flight engineer to do the air tests?

If they were incapacitated, it would have the least impact on an evacuation. FE2 is the "tourist" seat.

sequence seating crew of the Soyuz
FE1
FE2
Soyuz Commander

escape sequence crew of Soyuz spacecraft
Soyuz Commander
FE2
FE1

[dks13827]

A real emergency of this kind is bad anywhere but what if you were months away from Earth ?

[erioladastra]

Ok, I know the right seat is the 2nd Flight Engineer. So why would it make sense to send the 2nd flight engineer to do the air tests?

If they were incapacitated, it would have the least impact on an evacuation. FE2 is the "tourist" seat.

sequence seating crew of the Soyuz
FE1
FE2
Soyuz Commander

escape sequence crew of Soyuz spacecraft
Soyuz Commander
FE2
FE1

Depends on skill mix and CDR preference at the time - nothing to do with seats or who would be least impact.

[rdale]

A real emergency of this kind is bad anywhere but what if you were months away from Earth ?

That would also be bad. But that's not possible on the ISS due to its need to orbit the Earth.

[the_other_Doug]

Ok, I know the right seat is the 2nd Flight Engineer. So why would it make sense to send the 2nd flight engineer to do the air tests?

If they were incapacitated, it would have the least impact on an evacuation. FE2 is the "tourist" seat.

sequence seating crew of the Soyuz
FE1
FE2
Soyuz Commander

escape sequence crew of Soyuz spacecraft
Soyuz Commander
FE2
FE1

Depends on skill mix and CDR preference at the time - nothing to do with seats or who would be least impact.

The evacuation seats are literally all pre-located, correct?  Each Expedition crew member has his/her custom-molded Soyuz seat liner, and these are pre-installed in the Soyuz to which a given crew member is assigned for evacuation, right?

So, at any given time, an evacuating crew member ought to have one, and only one, Soyuz seat to try and get to in an emergency?

[Hog]

Ok, I know the right seat is the 2nd Flight Engineer. So why would it make sense to send the 2nd flight engineer to do the air tests?

If they were incapacitated, it would have the least impact on an evacuation. FE2 is the "tourist" seat.

sequence seating crew of the Soyuz
FE1
FE2
Soyuz Commander

escape sequence crew of Soyuz spacecraft
Soyuz Commander
FE2
FE1

Depends on skill mix and CDR preference at the time - nothing to do with seats or who would be least impact.

The evacuation seats are literally all pre-located, correct?  Each Expedition crew member has his/her custom-molded Soyuz seat liner, and these are pre-installed in the Soyuz to which a given crew member is assigned for evacuation, right?

So, at any given time, an evacuating crew member ought to have one, and only one, Soyuz seat to try and get to in an emergency?

Would they not evacuate to the seat that they rode up on?

[ThereIWas3]

A real emergency of this kind is bad anywhere but what if you were months away from Earth ?

That would also be bad. But that's not possible on the ISS due to its need to orbit the Earth.

I think dks's question was speculative about BEO missions.   These ISS MDMs seem unreliable (they had to replace the external one last year) so hopefully by then they will have come up with a more reliable and more distributed design.  From the pictures, these things are using rather old technology.

[Fuji]

C&W display and laptop screen are red. Rare photos

http://www.federalspace.ru/21249/