STS-115: Troubleshooting/MMT evaluations - Sept 7

• #20 by nathan.moeller on 07 Sep, 2006 13:16
• Sounds like North will definitely have some good input for the MMT.  What doe EGIL stand for again?  That e-mail definitely makes me doubt that they'll go for a launch attempt tomorrow.  Press briefing still scheduled for 12 noon EDT?
• #21 by psloss on 07 Sep, 2006 13:21
• Quote

  Chris Bergin - 7/9/2006  8:53 AM
  
  

  Quote

  joncz - 7/9/2006  1:47 PM
  
  Who does Tim North represent?
  

  
  The EGIL officer on console for the STS-93 ascent. Could be influential. Might make an article out of this anyway.

  FWIW,
  
  EGIL = "Electrical Generation and Illumination Engineer"
  
  References (Google for more):
  http://space.balettie.com/MCC.html
  http://www.nasa.gov/audience/foreducators/k-4/features/F_People_Behind_the_Astronauts.html
  
• #22 by Svetoslav on 07 Sep, 2006 13:21
• I suggest they should restart the cell and reactivate it again. If it's OK, they should proceed with launch with an acceptable risk.
• #23 by Chris Bergin on 07 Sep, 2006 13:23
• Quote

  nathan.moeller - 7/9/2006  2:03 PM
  
  briefing still scheduled for 12 noon EDT?

  
  No, the MMT is scheduled to start at midday CENTRAL (1pm EDT, 6pm UK). Press conference will be a few hours later.
• #24 by Jonesy STS on 07 Sep, 2006 13:24
• Those Poll comments on the article on site are really interesting. Could go either ways. Griffin "Phase A sucks"
• #25 by psloss on 07 Sep, 2006 13:27
• Quote

  Svetoslav - 7/9/2006  9:08 AM
  
  I suggest they should restart the cell and reactivate it again. If it's OK, they should proceed with launch with an acceptable risk.

  Why is it OK?  What are you basing that on?
  
• #26 by Delta Manager on 07 Sep, 2006 13:31
• Quote

  Chris Bergin - 7/9/2006  7:36 AM
  
  20 more documents/presentations to today's MMT on L2. Some are fascinating, especially the e-mail from Tim North saying "no go".
  
   Also, 10 new images of the Fuel Cell in questions (some likely taken last night).

  
  Just been skimming through and I need to work today , I won't if I read them all, but the on-pad R&R is superb and should be an article too. Been in the industry 20 years and never seen such an insight into NASA at work than this, but it's also encouraging to see the depth NASA are going to on this.
• #27 by Svetoslav on 07 Sep, 2006 13:31
• if it's performing as yesterday after the restart, if the output voltage is as expected, if... if it's perfect.
• #28 by nathan.moeller on 07 Sep, 2006 13:34
• Quote

  Svetoslav - 7/9/2006  8:18 AM
  
  if it's performing as yesterday after the restart, if the output voltage is as expected, if... if it's perfect.

  
  They know the cell is working, but again, they don't want to fly with hardware they know could possibly fail in flight and cut the mission short.  They're going to try to develop flight rationale but I wouldn't get my hopes up.  They're looking at what COULD happen.
• #29 by psloss on 07 Sep, 2006 13:38
• Quote

  Delta Manager - 7/9/2006  9:18 AM
  
  Just been skimming through and I need to work today , I won't if I read them all, but the on-pad R&R is superb and should be an article too. Been in the industry 20 years and never seen such an insight into NASA at work than this, but it's also encouraging to see the depth NASA are going to on this.

  I agree -- I also liked the accompanying e-mail showing some deviations between the expected physical layout in the area of the fuel cell and what they found looking at the candidate replacement fuel cell.
  
• #30 by psloss on 07 Sep, 2006 13:43
• Quote

  Svetoslav - 7/9/2006  9:18 AM
  
  if it's performing as yesterday after the restart, if the output voltage is as expected, if... if it's perfect.

  I don't see that those two data points necessarily lead to the conclusion that the fuel cell is perfect -- it's not that simplistic a choice.  There are lots of other factors to consider.
  
• #31 by Felix on 07 Sep, 2006 14:08

• I still hope they're launching on Friday. There is neither a violation of LCC nor a safety of flight risk. They could still achieve their major goals (collecting ET data and bolting P4/5 truss segment to ISS) even if they loose FC1 (worst case scenario). A launch in late september looks much more threatening:

  • Increased risk in following flights because they cant improve the ET (as planned)
     
  • No guarantee that weather will be fine
  • Another storm/hurricane could force them to rollback  
• #32 by psloss on 07 Sep, 2006 14:17
• Quote

  Felix - 7/9/2006  9:55 AM
  
  

  I still hope they're launching on Friday. There is neither a violation of LCC nor a safety of flight risk. They could still achieve their major goals (collecting ET data and bolting P4/5 truss segment to ISS) even if they loose FC1 (worst case scenario). A launch in late september looks much more threatening:

  • Increased risk in following flights because they cant improve the ET (as planned)
     
  • No guarantee that weather will be fine
  • Another storm/hurricane could force them to rollback  

  1. They've already downselected a new IFR design.
  2. No guarantees on the weather, period.  Why is early September better than late September?
• #33 by jacqmans on 07 Sep, 2006 14:23
• Quote

  Felix - 7/9/2006  3:55 PM
  
  and bolting P4/5 truss segment to ISS)

  
  
  They are going to take the P3/4 segment up....
  
   
• #34 by Felix on 07 Sep, 2006 14:35
• Quote

  psloss - 7/9/2006  9:04 AM
  

  1. They've already downselected a new IFR design.
  2. No guarantees on the weather, period.  Why is early September better than late September?

   

  1. They've downselected the final design?

  2. There's a promising (70%) forecast for tomorrow and there is a chance that weather will prohibt launch in late september.  It's an unpredictable "risk".

   

• #35 by Spiff on 07 Sep, 2006 14:38
• I have a question that I have not been able to find an answer on so far. (Might be on L2, dunno.)
  
  This FC is the same one as the one with similar anomalous behaviour on STS-93. Has it been flown on any other flight since then?
  If so: Did it perform nominally?
  If not: Why not? And why decide to reinstall it for this mission? (And about a million related questions that I'll hold back until these get an answer. )
• #36 by Jim on 07 Sep, 2006 14:40
• Quote

  Felix - 7/9/2006  9:55 AM
  They could still achieve their major goals (collecting ET data and bolting P4/5 truss segment to ISS) even if they loose FC1 (worst case scenario).

  
  not if they lose it early
• #37 by Felix on 07 Sep, 2006 14:44

• Quote

  Jim - 7/9/2006  9:27 AM  

  Quote

  Felix - 7/9/2006  9:55 AM They could still achieve their major goals (collecting ET data and bolting P4/5 truss segment to ISS) even if they loose FC1 (worst case scenario).

   not if they lose it early

   'Shannon - have shown this is not a crew safety issue. Sufficient redundancy in fuel cell to get to orbit. Potentially drop controllers offline, but not an abort. Program needs to weigh if can?t complete mission or push to stage. Team needs to keep working. The programmatic risk of delay is not worth it for this issue.
  

  'LeRoy (Cain) - no violation of LCC, launching with full SSME controllers. [..] Program risk not safety of flight risk. No impact to mission for loss of single phase. Fuel cell performance has been very good since start up. [..] Risk to R&R at the PAD is unknown and a concern. [..] Rolling back is even more risk to both programs because of the October launch. Can fly safe and not get much more data anytime soon. We have never had perfect data.

  From: http://www.nasaspaceflight.com/content/?cid=4770
  

• #38 by Chris Bergin on 07 Sep, 2006 14:44
• And North is on the team it would appear:
  
  0800 OPO Telecon on AC1 Phase A (-----)
  
  - OV-104 Fuel Cell Performance to date plot (------)
  
  - OV-104 Fuel Cell History (------)
  
  - Worst-case Ascent Performance Margin (--------)
  
  - Motor Dissection (T. North)
  
  - Fuel Cell Photos/Pictures (------)
  
  This telecon has begun.
• #39 by Chris Bergin on 07 Sep, 2006 14:45
• Tomorrow's launch attempt run down now noted:
  
  9/8  FRI  (launch attempt, if reqd)
  
    0000  ET Tanking Weather Briefing
  
    0045  Earliest Tanking Operations
  
    0700  Full MER Pre-Launch Team Call to Stations
  
    1035  Launch Window Opens