Ammonia Pump Forensics?

Since we cannot return the broken ammonia pump for failure analysis on the ground are there any plans to conduct forensics on orbit?
Would the bulk of this work require EVAs to accomplish? What, if any, forensics have been done so far?

Dave

If there is an additional Shuttle flight added to the current manifest
(which must be in some doubt), then one of the priorities would surely be to
take the opportunity to return whatever can be retrieved from the Station.

On the other hand, I wonder if there is any way to rig the Shuttle to return
the ammonia pump on the payload bay carrier that will house AMS-2 for
delivery to ISS? How compatible/incompatible is this carrier for the ammonia
pump?

Eddie Lyons
Portsmouth, UK


"David Spain" wrote in message
...
Since we cannot return the broken ammonia pump for failure analysis on the
ground are there any plans to conduct forensics on orbit? Would the bulk
of this work require EVAs to accomplish? What, if any, forensics have been
done so far?

Dave

Jorge R. Frank wrote:
Will not happen on 134 (AMS flight). Will happen on 135 if 135 is
approved and funded.

Jorge,

How many shuttle flights could be approved after 134? I thought the limiting
factor was the fact that Michaud has been shut down and there are only a
limited number of ETs available?

Dave

David Spain wrote:
What, if any, forensics have been done so far?

For example has anyone tried fault insertion testing on a ground mock-up to
see if what failures can be induced that mimic as closely as possible what was
observed on the ISS? Do we know at the time of failure things like pump motor
current draw? Component temperatures? Was there any flow of coolant at all?
Are we talking frozen pump? Bad electrical connections? Leaky lines?

Is Google my friend or maybe this is being kept current on a blog somewhere
that I'm missing? Links always appreciated.

Dave

Jorge R. Frank wrote:
Will not happen on 134 (AMS flight). Will happen on 135 if 135 is
approved and funded.

Does that imply STS-135 will also be flying another spare pump up?

Dave

On 09/11/2010 10:20 PM, David Spain wrote:
Jorge R. Frank wrote:
Will not happen on 134 (AMS flight). Will happen on 135 if 135 is
approved and funded.

Does that imply STS-135 will also be flying another spare pump up?

No, there are enough spare pump modules up there now.

On 09/11/2010 05:15 PM, David Spain wrote:
Jorge R. Frank wrote:
Will not happen on 134 (AMS flight). Will happen on 135 if 135 is
approved and funded.

Jorge,

How many shuttle flights could be approved after 134? I thought the
limiting factor was the fact that Michaud has been shut down and there
are only a limited number of ETs available?

STS-134 and 335 are planned to be stacked with ET-138 and 122. It is
probable that if 135 is approved that the ETs will be swapped and 122
will fly on 134, since 122 is the "Katrina tank" and NASA doesn't want
to fly that one on a flight that doesn't have a LON rescue flight after it.

There are no other completed SLWTs. There is one LWT that can be
refurbished (ET-94) and enough piece parts to assemble a few more SLWTs
(ET-139 through 141, IIRC).

Jorge R. Frank wrote:
On 09/11/2010 05:15 PM, David Spain wrote:
Jorge R. Frank wrote:
Will not happen on 134 (AMS flight). Will happen on 135 if 135 is
approved and funded.

Jorge,

How many shuttle flights could be approved after 134? I thought the
limiting factor was the fact that Michaud has been shut down and there
are only a limited number of ETs available?

STS-134 and 335 [135?] are planned to be stacked with ET-138 and 122. It is
probable that if 135 is approved that the ETs will be swapped and 122
will fly on 134, since 122 is the "Katrina tank" and NASA doesn't want
to fly that one on a flight that doesn't have a LON rescue flight after it.

Geez, cutting it close aren't we? STS-134 is scheduled for Feb 26. When is the
commit date to pick an ET?

There are no other completed SLWTs. There is one LWT that can be
refurbished (ET-94) and enough piece parts to assemble a few more SLWTs
(ET-139 through 141, IIRC).

So if I did my math correctly [always a problem ;-)] there are two ETs
available, but one only for use if there is no LON (Launch On Need?) backup.
Enough piece parts to assemble 3 more and a possible one can be refurbished.
That's a total of six more if we play our cards right. And ttttthat's all folks.

Hmm, how close does that get us to a manned Dragon if we drag that out to one
(shuttle) per year? Can we bridge the gap?

Dave

On 09/12/2010 01:20 PM, David Spain wrote:
Jorge R. Frank wrote:
On 09/11/2010 05:15 PM, David Spain wrote:
Jorge R. Frank wrote:
Will not happen on 134 (AMS flight). Will happen on 135 if 135 is
approved and funded.

Jorge,

How many shuttle flights could be approved after 134? I thought the
limiting factor was the fact that Michaud has been shut down and there
are only a limited number of ETs available?

STS-134 and 335 [135?] are planned to be stacked with ET-138 and 122.
It is probable that if 135 is approved that the ETs will be swapped
and 122 will fly on 134, since 122 is the "Katrina tank" and NASA
doesn't want to fly that one on a flight that doesn't have a LON
rescue flight after it.

Geez, cutting it close aren't we? STS-134 is scheduled for Feb 26. When
is the
commit date to pick an ET?[/quote]

Right after we find out if 135 is going to happen or not.

There are no other completed SLWTs. There is one LWT that can be
refurbished (ET-94) and enough piece parts to assemble a few more
SLWTs (ET-139 through 141, IIRC).

So if I did my math correctly [always a problem ;-)] there are two ETs
available, but one only for use if there is no LON (Launch On Need?)
backup. Enough piece parts to assemble 3 more and a possible one can be
refurbished. That's a total of six more if we play our cards right. And
ttttthat's all folks.

Hmm, how close does that get us to a manned Dragon if we drag that out
to one
(shuttle) per year? Can we bridge the gap?

Sure, at the right price.

On Sep 11, 11:46*pm, JF Mezei wrote:
David Spain wrote:
Since we cannot return the broken ammonia pump for failure analysis on the ground are there any plans to conduct forensics on orbit?
Would the bulk of this work require EVAs to accomplish? What, if any, forensics have been done so far?

Is there any way to purge/safe the pump to eliminate any ammonia and
make it safe to be brought into the ISS for disassembly and forensics ?

Could DEXTR be used to open the pump outdoors and take a look inside ?
Not as good as real examination and touching by a human hand, but still
better than throwing it overboard.

I thought the working hypothesis was a control unit issue, perhaps
failed electronics components (or power components) ,,, did I misread?

If the control unit(s) can be extracted easily, ammonia wouldn't be an
issue and that might fit in a shuttle return bag, or (if individual
boards) even in a Soyuz. But that would also depend on the unit not
requiring special tools for disassembly.

/dps