dgates - 12/1/2008 8:04 AMIs this why the external discussion on the subject of SARJ damage "way forward" has been so muted?
erioladastra - 13/1/2008 4:22 PMCurrent leaning is to grease it up (replace the lubrication which is the leading failure right now).....
Lawntonlookirs - 14/1/2008 11:55 AMI remember on STS 117 when they were doing some EVA on the solar panels. If I remember they had some tools that were missing and some wiring on the solar panel. Is it possible that one of the tools that were missing got caught up in the SARJ, or the wiring problem had something to do with the premature wearing of the SARJ? I don't recall hearing much more about the tools or the wiring as the attention starting going toward a problem with a flight controller computer, and the torn insulation panel on the shuttle.
Lawntonlookirs - 14/1/2008 8:55 AMI remember on STS 117 when they were doing some EVA on the solar panels. If I remember they had some tools that were missing and some wiring on the solar panel. Is it possible that one of the tools that were missing got caught up in the SARJ, or the wiring problem had something to do with the premature wearing of the SARJ? I don't recall hearing much more about the tools or the wiring as the attention starting going toward a problem with a flight controller computer, and the torn insulation panel on the shuttle.
Lee Jay - 14/1/2008 1:24 PMIf this were caused by dragging a hard object against the race ring, the observed damage would be scoring, not the observed spalling or macropitting. Incidentally, I don't understand how a lack of lubrication would have caused either failure mode. I would think that would lead to micropitting or scuffing. Perhaps it did and the micropitting turned into macropitting over time, but my poorly-informed guess is that it just doesn't have enough cycles on it for that.
stockman - 14/1/2008 6:26 PMQuoteLee Jay - 14/1/2008 1:24 PMIf this were caused by dragging a hard object against the race ring, the observed damage would be scoring, not the observed spalling or macropitting. Incidentally, I don't understand how a lack of lubrication would have caused either failure mode. I would think that would lead to micropitting or scuffing. Perhaps it did and the micropitting turned into macropitting over time, but my poorly-informed guess is that it just doesn't have enough cycles on it for that.I agree on that one as well. Especially since the other SARJ is older and yet is in pristine working condition.
litton4 - 14/1/2008 11:42 AMQuotestockman - 14/1/2008 6:26 PMQuoteLee Jay - 14/1/2008 1:24 PMIf this were caused by dragging a hard object against the race ring, the observed damage would be scoring, not the observed spalling or macropitting. Incidentally, I don't understand how a lack of lubrication would have caused either failure mode. I would think that would lead to micropitting or scuffing. Perhaps it did and the micropitting turned into macropitting over time, but my poorly-informed guess is that it just doesn't have enough cycles on it for that.I agree on that one as well. Especially since the other SARJ is older and yet is in pristine working condition.I thought that the current thinking was that the preload on the TBA or DLA had been set too high, resulting in voids under the Nitride layer on the ring being "crushed", resulting in spalling of fragments from the affected face.
litton4 - 14/1/2008 12:42 PMQuotestockman - 14/1/2008 6:26 PMQuoteLee Jay - 14/1/2008 1:24 PMIf this were caused by dragging a hard object against the race ring, the observed damage would be scoring, not the observed spalling or macropitting. Incidentally, I don't understand how a lack of lubrication would have caused either failure mode. I would think that would lead to micropitting or scuffing. Perhaps it did and the micropitting turned into macropitting over time, but my poorly-informed guess is that it just doesn't have enough cycles on it for that.I agree on that one as well. Especially since the other SARJ is older and yet is in pristine working condition.I thought that the current thinking was that the preload on the TBA or DLA had been set too high, resulting in voids under the Nitride layer on the ring being "crushed", resulting in spalling of fragments from the affected face.
I presume that flying another S3/S4/S5 assembly is out of the question (even assuming you could extent the Shuttle life to allow time for that before further major construction.
Could they install an additional (shortened) array back on Z0 to augment the stalled arrays?