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#100
by
psloss
on 06 Dec, 2007 14:46
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Just repeating, but the post MMT briefing is scheduled for approximately 4 pm local.
(Edit -- changing NET to approx., as that's what George Diller said.)
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#101
by
shuttlefan
on 06 Dec, 2007 14:50
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So the ET was filled up to 100% today then, or can they put it into stable replenish even when it's not full?
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#102
by
Chris Bergin
on 06 Dec, 2007 14:52
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shuttlefan - 6/12/2007 3:50 PM
So the ET was filled up to 100% today then, or can they put it into stable replenish even when it's not full?
Good question. We know they went to 80 percent. We know they stopped. Question is if - when they decided to use the opportunity to send the Ice Team out there - they then went and filled up, to bring the tank to stable replenish (I would guess so. I'll grab and ET guy and find out, but they are all rather busy, as I'm sure you can understand!)
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#103
by
dember
on 06 Dec, 2007 14:55
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Hopefully they can get off the ground tomorrow.
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#104
by
ShuttleDiscovery
on 06 Dec, 2007 14:59
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dember - 6/12/2007 3:55 PM
Hopefully they can get off the ground tomorrow.
Let's just hope the weather holds out..
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#105
by
John2375
on 06 Dec, 2007 15:05
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Since this has happened before, would it be possible for them to do a mini-tanking test when they get to the pad? just to see how the sensors are acting? Or would the be useless since odds are, tomorrow, they'll be just fine..
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#106
by
psloss
on 06 Dec, 2007 15:07
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ShuttleDiscovery - 6/12/2007 10:59 AM
dember - 6/12/2007 3:55 PM
Hopefully they can get off the ground tomorrow.
Let's just hope the weather holds out..
Given the situation, I'd say weather is far down on the list of concerns. I'd trade most poor weather conditions for this anomaly because in most weather cases they can come back tomorrow. It's still very much undecided (at least from the outside looking in) whether that's the case currently.
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#107
by
John44
on 06 Dec, 2007 15:07
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#108
by
psloss
on 06 Dec, 2007 15:08
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Thanks for turning that around so quickly, John44.
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#109
by
shuttlefan
on 06 Dec, 2007 15:15
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John2375 - 6/12/2007 10:05 AM
Since this has happened before, would it be possible for them to do a mini-tanking test when they get to the pad? just to see how the sensors are acting? Or would the be useless since odds are, tomorrow, they'll be just fine..
Well, if you mean WHEN THE TECHNICIANS GET TO THE PAD, no, because the pad has to be completely evacuated when the propellant is actually flowing.
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#110
by
Lee Jay
on 06 Dec, 2007 15:18
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If the issue is not with the sensors themselves, but rather with electrical connectivity, why would it not have been detected during the run-up to launch day? They seem to have the ability to test most, if not all of the electrical connections on the stack prior to actual use.
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#111
by
shuttlefan
on 06 Dec, 2007 15:18
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Chris Bergin - 6/12/2007 9:52 AM
shuttlefan - 6/12/2007 3:50 PM
So the ET was filled up to 100% today then, or can they put it into stable replenish even when it's not full?
Good question. We know they went to 80 percent. We know they stopped. Question is if - when they decided to use the opportunity to send the Ice Team out there - they then went and filled up, to bring the tank to stable replenish (I would guess so. I'll grab and ET guy and find out, but they are all rather busy, as I'm sure you can understand!)
Yep, thanks in advance Chris!!
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#112
by
psloss
on 06 Dec, 2007 15:23
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Lee Jay - 6/12/2007 11:18 AM
If the issue is not with the sensors themselves, but rather with electrical connectivity, why would it not have been detected during the run-up to launch day? They seem to have the ability to test most, if not all of the electrical connections on the stack prior to actual use.
In the past cases, the behavior has been intermittent and seemed to only occur under cryogenic conditions. (In other words: test the sensors at ambient and they behave one way; then test the sensors during tanking at cryogenic temps and then they exhibit multiple behaviors.)
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#113
by
TrueBlueWitt
on 06 Dec, 2007 15:24
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While I want to see the shuttle launch as soon as possible, I'll be in Orlando over New Years and would absolutely LOVE to take kids to see our first shuttle launch while down there!
Is there a scenario with a Jan 2 launch date? Seems like any work would have to be done at the pad, not enough time to roll back?
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#114
by
DaveS
on 06 Dec, 2007 15:29
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psloss - 6/12/2007 5:23 PM
Lee Jay - 6/12/2007 11:18 AM
If the issue is not with the sensors themselves, but rather with electrical connectivity, why would it not have been detected during the run-up to launch day? They seem to have the ability to test most, if not all of the electrical connections on the stack prior to actual use.
In the past cases, the behavior has been intermittent and seemed to only occur under cryogenic conditions. (In other words: test the sensors at ambient and they behave one way; then test the sensors during tanking at cryogenic temps and then they exhibit multiple behaviors.)
Yes. During the extensive troubleshooting activities between the first and second launch attempts of STS-114 they spent nearly two weeks trying to recreate the problems with the ECO sensor system in ambient temps with no results leading them to recommend going to cryogenic temps.
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#115
by
Chris Bergin
on 06 Dec, 2007 15:37
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TrueBlueWitt - 6/12/2007 4:24 PM
While I want to see the shuttle launch as soon as possible, I'll be in Orlando over New Years and would absolutely LOVE to take kids to see our first shuttle launch while down there!
Is there a scenario with a Jan 2 launch date? Seems like any work would have to be done at the pad, not enough time to roll back?
We'll be continuing with this thread through troubleshooting.
Right now it's NET tomorrow. Data being collected for the engineering community. Engineers will tag-up (Orbiter, ET Project etc). Go to MMT. Work the forward plan.
All depends on the location of the fault on how long the wait will be, and we're working on that info via L2. Will summarize here/article later on.
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#116
by
Maverick
on 06 Dec, 2007 15:50
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Super George - 6/12/2007 8:02 AM
Chris Bergin - 6/12/2007 8:00 AM
Quotes and notes from L2 coverage are going into the main article, remember:
http://www.nasaspaceflight.com/content/?cid=5302
No one else is reporting this (SFN, Florida Today). You sure?
Hah, welcome to the site
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#117
by
Lee Jay
on 06 Dec, 2007 16:09
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DaveS - 6/12/2007 9:29 AM
psloss - 6/12/2007 5:23 PM
Lee Jay - 6/12/2007 11:18 AM
If the issue is not with the sensors themselves, but rather with electrical connectivity, why would it not have been detected during the run-up to launch day? They seem to have the ability to test most, if not all of the electrical connections on the stack prior to actual use.
In the past cases, the behavior has been intermittent and seemed to only occur under cryogenic conditions. (In other words: test the sensors at ambient and they behave one way; then test the sensors during tanking at cryogenic temps and then they exhibit multiple behaviors.)
Yes. During the extensive troubleshooting activities between the first and second launch attempts of STS-114 they spent nearly two weeks trying to recreate the problems with the ECO sensor system in ambient temps with no results leading them to recommend going to cryogenic temps.
This I understand, but I don't understand why cryo in the tank would affect electrical connectivity in the orbiter aft, or areas even further up-stream from there.
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#118
by
Chandonn
on 06 Dec, 2007 16:15
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Correct me if I'm wrong, but aren't the tanks used since RTF, up through this flight, tanks that were all or partially-built pre-RTF then modified with the RTF modifications? Also, hasn't the ECO sensor issue only been prevalent since RTF? If so, then perhaps there is some commonality with the mods and this issue.
EDIT: In particular, I'm concerned with the electrical trays and the bipod ramps, although I would expect them to have more effect on the O2 sensors than the H2...
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#119
by
Jorge
on 06 Dec, 2007 16:46
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John2375 - 6/12/2007 10:05 AM
Since this has happened before, would it be possible for them to do a mini-tanking test when they get to the pad? just to see how the sensors are acting? Or would the be useless since odds are, tomorrow, they'll be just fine..
Tanking the vehicle puts thermal stress on the tank and is believed to be a factor in foam liberation from the tank. So NASA wants to perform as few tanking cycles as possible. Therefore there is no point in a separate tanking test; the actual tanking for the launch attempt constitutes the test.
