Post by: Chris Bergin on 12/06/2007 09:31 am
This is the live update thread for the launch. Should we have a successful launch, it will continue as the Flight Day 1 Live Update thread.
Below are the rules for what is always a very busy day on this site (please take note):
Firstly, if you are guest, please note it is reccomended that you create yourself a login, as we protect the site's servers in the event of overloading by making it member only, see here: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=10291&posts=4&start=1 (membership to the open sections of the site is free).
This is a live update thread, so we do not want any "woo hoo, go Atlantis" comments clogging up the updates. We have a cheerleading thread for your best wishes:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=10978&start=1
We also have a seperate weather specific thread, for comments on the status of the pre-launch weather: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=11028&posts=13&start=1
If you are in Florida for the launch and need tips on where to go for best viewing, we have a thread for that: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=10458&start=1
All NASA TV video for the mission is available - for free - here: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=10045&start=1
If you're learning about the Shuttle - and let's face it, we all are unless your Wayne Hale - you are encouraged to ask questions, but please keep them here: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=10600&start=1
Moderators will delete - without notification - any posts that do not follow the above request.
God Speed Atlantis.
Post by: Chris Bergin on 12/06/2007 09:36 am
This is not unlike previous, and we're waiting now for the go for tanking.
Post by: Chris Bergin on 12/06/2007 10:04 am
Post by: Chris Bergin on 12/06/2007 10:20 am
Post by: Bruce on 12/06/2007 10:23 am
Post by: marshallsplace on 12/06/2007 10:48 am
Post by: Chris Bergin on 12/06/2007 10:51 am
Post by: Spiff on 12/06/2007 11:06 am
:)
Post by: Chris Bergin on 12/06/2007 11:11 am
Bipod area and a dawn Atlantis.
Post by: Chris Bergin on 12/06/2007 11:20 am
Post by: psloss on 12/06/2007 11:24 am
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Chris Bergin - 6/12/2007 7:20 AMAnd one of the feedline brackets. (And the cable tray, etc.)
17 inch LOX Feedline (about to get rather cold!). Nice look at an IFR (Ice Frost Ramp) too.
Post by: Chris Bergin on 12/06/2007 11:25 am
Post by: Chris Bergin on 12/06/2007 11:37 am
Meanwhile...
Post by: shuttlefan on 12/06/2007 11:38 am
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Chris Bergin - 6/12/2007 6:37 AM
Troubleshooting a communications asset. Still has redundancy.
Meanwhile...
So no constraint to launch?
Post by: Chris Bergin on 12/06/2007 11:41 am
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shuttlefan - 6/12/2007 12:38 PMQuoteChris Bergin - 6/12/2007 6:37 AM
Troubleshooting a communications asset. Still has redundancy.
Meanwhile...
So no constraint to launch?
Working the info on L2. LCC allows for 1 of 2. Preference is 2, hense troubleshooting. Technically no constraint to launch on the LCC.
Post by: psloss on 12/06/2007 11:42 am
(bottom is one of the end of the runway cams at the SLF)
Post by: Chris Bergin on 12/06/2007 11:59 am
Post by: Ford Mustang on 12/06/2007 12:11 pm
Post by: Ford Mustang on 12/06/2007 12:13 pm
Post by: Ford Mustang on 12/06/2007 12:26 pm
Post by: Ford Mustang on 12/06/2007 12:32 pm
Post by: Ford Mustang on 12/06/2007 12:38 pm
Post by: Chris Bergin on 12/06/2007 12:47 pm
Post by: Chris Bergin on 12/06/2007 12:49 pm
Post by: John2375 on 12/06/2007 12:50 pm
Post by: DaveS on 12/06/2007 12:51 pm
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John2375 - 6/12/2007 2:50 PMYes and 115.
Crap-O-la.. ECO sensors - remind me - those the fuel cutoff sensors in the tank that gave problems on 114?
Post by: dember on 12/06/2007 12:52 pm
Post by: Chris Bergin on 12/06/2007 12:56 pm
Post by: makims on 12/06/2007 12:56 pm
Post by: psloss on 12/06/2007 12:57 pm
Post by: John2375 on 12/06/2007 12:59 pm
If they can't and they scrub, what can they do to be sure it doesnt' happen at the next attempt?? And would that be a 24 or 48 hr. scrub? or more?
Post by: Chris Bergin on 12/06/2007 01:00 pm
http://www.nasaspaceflight.com/content/?cid=5302
Post by: dember on 12/06/2007 01:01 pm
Post by: Super George on 12/06/2007 01:02 pm
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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?
Post by: psloss on 12/06/2007 01:03 pm
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John2375 - 6/12/2007 8:59 AMThey better fix it because...why? They are working on it, they have been working on the UA since spring 2005 when they first saw it. All we can do on the outside is observe.
yeah it's GORGEOUS here in FL today.. and Mom was ready to watch in the SE sky up in New England to see it today too :( they better fix it.
If they can't and they scrub, what can they do to be sure it doesnt' happen at the next attempt?? And would that be a 24 or 48 hr. scrub? or more?
Post by: lbiderman on 12/06/2007 01:03 pm
Post by: Chris Bergin on 12/06/2007 01:04 pm
Crikey, and rollback (not official).
Post by: SCE2Aux on 12/06/2007 01:07 pm
Post by: shuttlefan on 12/06/2007 01:08 pm
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SCE2Aux - 6/12/2007 8:07 AM
ECO sensors again? This is beyond ridiculous.
You've got that right! :angry:
Post by: Gary on 12/06/2007 01:09 pm
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Chris Bergin - 6/12/2007 2:04 PM
SCRUB is what we're hearing on L2.
Crikey, and rollback (not official).
I'm guessing they may want to swap these sensors out. If it's a rollback then launch won't be until next year and that's going to impact all the other launches... damn and all that hard work done on the ISS to relocate Harmony.
Post by: lbiderman on 12/06/2007 01:10 pm
Post by: psloss on 12/06/2007 01:10 pm
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SCE2Aux - 6/12/2007 9:07 AMI don't know why it's ridiculous. If this is related to the previous cases, it's still unexplained behavior, which makes it hard to "fix." If it isn't fixed, then I don't see why it couldn't happen again.
ECO sensors again? This is beyond ridiculous.
Post by: shuttlefan on 12/06/2007 01:12 pm
Post by: Bruce on 12/06/2007 01:14 pm
Post by: Gary on 12/06/2007 01:15 pm
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Bruce - 6/12/2007 2:14 PM
It must be disappointing enough for the astronauts for a 24/48 hour postponement. But a "come back after Christmas" must be a real kick in the pants for them :( And all the ESA people too. But, that's life in the space industry I guess.
And for Dan Tani's family. If this is a rollback then he is stuck in orbit over Christmas.
Post by: Bejowawo on 12/06/2007 01:15 pm
So I guess this could mean they are still filling the tank - or the just are not as fast as this website
Thanks for the excellent coverage!
Post by: Lee Jay on 12/06/2007 01:16 pm
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Gary - 6/12/2007 7:15 AMQuoteBruce - 6/12/2007 2:14 PM
It must be disappointing enough for the astronauts for a 24/48 hour postponement. But a "come back after Christmas" must be a real kick in the pants for them :( And all the ESA people too. But, that's life in the space industry I guess.
And for Dan Tani's family. If this is a rollback then he is stuck in orbit over Christmas.
Heavy on "if". Rollback is far from certain.
Post by: Chris Bergin on 12/06/2007 01:17 pm
Post by: dember on 12/06/2007 01:20 pm
Post by: Chris Bergin on 12/06/2007 01:21 pm
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Bejowawo - 6/12/2007 2:15 PM
So I guess this could mean they are still filling the tank - or the just are not as fast as this website
They stopped loading the tank a while ago.
Post by: dember on 12/06/2007 01:21 pm
Post by: SCE2Aux on 12/06/2007 01:23 pm
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psloss - 5/12/2007 2:10 PMQuoteSCE2Aux - 6/12/2007 9:07 AMI don't know why it's ridiculous. If this is related to the previous cases, it's still unexplained behavior, which makes it hard to "fix." If it isn't fixed, then I don't see why it couldn't happen again.
ECO sensors again? This is beyond ridiculous.
Whoever made these sensors did a shoddy job, that's what is ridiculous: How hard can it be for supposedly smart people to make a sensor whose sole purpose is to work out whether there's liquid in the tank or not?
Post by: Chris Bergin on 12/06/2007 01:24 pm
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SCE2Aux - 6/12/2007 2:23 PMQuotepsloss - 5/12/2007 2:10 PMQuoteSCE2Aux - 6/12/2007 9:07 AMI don't know why it's ridiculous. If this is related to the previous cases, it's still unexplained behavior, which makes it hard to "fix." If it isn't fixed, then I don't see why it couldn't happen again.
ECO sensors again? This is beyond ridiculous.
Whoever made these sensors did a shoddy job, that's what is ridiculous: How hard can it be for supposedly smart people to make a sensor whose sole purpose is to work out whether there's liquid in the tank or not?
Careful. It might not even be the sensors. Could be electrical paths, GSE, orbiter aft. etc.
Post by: Chandonn on 12/06/2007 01:27 pm
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dember - 6/12/2007 9:20 AM
Can this scrub be confirmed?
Good rule of thumb for newbies: this site is always ahead of the other news sites. There are actually people who work for NASA here, and a lot of the info here comes in real-time.
Post by: psloss on 12/06/2007 01:27 pm
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SCE2Aux - 6/12/2007 9:23 AMThere's a whole instrumentation circuit and so far they haven't been able to isolate the problem to a particular location in the circuit. In the meantime, they went through their sensor inventory, reverified the quality controls, and replaced sensors from suspect lots.
Whoever made these sensors did a shoddy job, that's what is ridiculous: How hard can it be for supposedly smart people to make a sensor whose sole purpose is to work out whether there's liquid in the tank or not?
How do you know it's the sensors?
Post by: Chandonn on 12/06/2007 01:28 pm
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SCE2Aux - 6/12/2007 9:23 AM
Whoever made these sensors did a shoddy job, that's what is ridiculous: How hard can it be for supposedly smart people to make a sensor whose sole purpose is to work out whether there's liquid in the tank or not?
It's safe to say that that we're all a bit frustrated at not having a launch today. But it's pointless to start laying blame or criticizing when we don't even know where the problem is yet.
Post by: Bejowawo on 12/06/2007 01:35 pm
Another question, just for clarification: There will be another lauch attempt tomorrow or is this too early to tell?
Post by: John2375 on 12/06/2007 01:35 pm
Post by: gordo on 12/06/2007 01:37 pm
Post by: shuttlefan on 12/06/2007 01:38 pm
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John2375 - 6/12/2007 8:35 AM
when it happened on -114, did they roll back or fix at the Pad??
On the pad.
Post by: John2375 on 12/06/2007 01:40 pm
Post by: psloss on 12/06/2007 01:41 pm
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Bejowawo - 6/12/2007 9:35 AMIn part because they don't know that the sensor is the root cause.
Why wouldn't they use another type of sensor (just as a backup) when they know they cannot fully trust those sensors currently used.
Post by: Satori on 12/06/2007 01:42 pm
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John2375 - 6/12/2007 8:40 AM
ok that's what I thought - so why is everyone saying "rollback!" if they coudl fix it there then maybe support a 1/2/08 launch?
What are the launch windows for this mission?
Post by: dember on 12/06/2007 01:43 pm
Post by: psloss on 12/06/2007 01:44 pm
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John2375 - 6/12/2007 9:40 AMBecause they may be able to see more data and/or analysis than we can. One of the things they did was add more instrumentation in the orbiter; that might help rule-in/rule-out things that they couldn't rule in or out during the last tanking with this issue on STS-115.
ok that's what I thought - so why is everyone saying "rollback!" if they coudl fix it there then maybe support a 1/2/08 launch?
Post by: Kreuzader on 12/06/2007 01:47 pm
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Satori - 6/12/2007 8:42 AM
What are the launch windows for this mission?
The launch period is December 6 through December 13.
Post by: Chandonn on 12/06/2007 01:48 pm
EDIT: redundant comment...
Post by: marktowler on 12/06/2007 01:50 pm
Post by: HKS on 12/06/2007 01:50 pm
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Approximately 16 minutes into fast fill, two ECO sensors failed to indicate wet. They are troubleshooting the issue. Currently, H2 is at 80% and O2 is at 50%. Tanking is continuing. We expect to have a status from leadership soon as to whether we continue or scrub. If we scrub, a briefing will follow that decision on NASA TV.http://www.nasa.gov/mission_pages/shuttle/main/index.html
Post by: dember on 12/06/2007 01:50 pm
Post by: Chris Bergin on 12/06/2007 01:56 pm
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dember - 6/12/2007 2:43 PM
Is it a confirmed scrub yet?
As in PAO? Not yet.
Post by: dember on 12/06/2007 01:58 pm
Post by: JimO on 12/06/2007 01:59 pm
http://spaceflightnow.com/shuttle/sts122/071206ecos/
Post by: Chris Bergin on 12/06/2007 02:01 pm
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dember - 6/12/2007 2:58 PM
thanks Chris
Should be soon. It's now over the loop they are scrubbed.
Post by: collectSPACE on 12/06/2007 02:02 pm
Post by: psloss on 12/06/2007 02:04 pm
Post by: Chris Bergin on 12/06/2007 02:04 pm
Remember, it might not be the sensors themselves - especially when these sensors in question are hand picked.
Post by: rfoshaug on 12/06/2007 02:10 pm
I know I had a bad case of go fever. ;)
Post by: Mark Dave on 12/06/2007 02:12 pm
Post by: Roci Stone on 12/06/2007 02:13 pm
Post by: dember on 12/06/2007 02:15 pm
Post by: Gary on 12/06/2007 02:17 pm
Post by: rdale on 12/06/2007 02:18 pm
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dember - 6/12/2007 10:15 AM
Launch weather for tomorrow?
Yep.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=11028
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Gary - 6/12/2007 10:17 AM
Have the ISS crew been informed?
Nothing heard on the ISS audio feed.
Post by: Chandonn on 12/06/2007 02:20 pm
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dember - 6/12/2007 10:15 AM
Launch weather for tomorrow?
The launch weather thread is here: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=11028&posts=16#M220242
It gets updated frequently, so is better to check it directly. Quick summary at the moment: KSC chance for showers is up a little bit, 2 of 3 TAL sites still good, slight chance of rain off the coast at Edwards for AOA.
Post by: Chandonn on 12/06/2007 02:22 pm
Post by: psloss on 12/06/2007 02:22 pm
Post by: ntschke on 12/06/2007 02:27 pm
Post by: psloss on 12/06/2007 02:27 pm
Edit -- this may be PAO commentary or PAO interviewing someone...
Post by: psloss on 12/06/2007 02:30 pm
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Gary - 6/12/2007 10:28 AMFYI, here's Bill Harwood's chart for December:Quotentschke - 6/12/2007 3:27 PM
What's the scheduled launch window for tomorrow if they get it all figured out?
Each day the launch window gets around 20 minutes earlier so expect it to be around 21:10 GMT.
http://www.cbsnews.com/network/news/space/122/122windows.html
Post by: Felix on 12/06/2007 02:34 pm
Mission Management Team Chairman LeRoy Cain concurred following a short briefing on the issue. The ice inspection team will proceed with an abbreviated vehicle inspection prior to offloading the LO2 and LH2 and recycle for a launch attempt tomorrow, at 4:09 p.m.
A press briefing is tentative scheduled for 3 p.m. An update is forthcoming on NASA TV. (nasa.gov)
Post by: dember on 12/06/2007 02:36 pm
Post by: rdale on 12/06/2007 02:36 pm
2 of the LH2 low-level cutoff sensors failed to show dry when they were simulated commanded.
(Those were MCC-Houston's words to ISS)
Post by: psloss on 12/06/2007 02:37 pm
Post by: rdale on 12/06/2007 02:37 pm
Post by: Felix on 12/06/2007 02:38 pm
Post by: rdale on 12/06/2007 02:41 pm
(MCC-Houston's words to a certain member onboard ISS :> )
Post by: psloss on 12/06/2007 02:41 pm
Post by: dutch courage on 12/06/2007 02:41 pm
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rdale - 6/12/2007 4:37 PM
"Hopefully it's just a connecter issue as that would be easiest to fix" (ISS ground)
Let's hope so or else it will be another rollback to the VAB.
Post by: psloss on 12/06/2007 02:43 pm
Post by: psloss on 12/06/2007 02:45 pm
Post by: psloss on 12/06/2007 02:46 pm
(Edit -- changing NET to approx., as that's what George Diller said.)
Post by: shuttlefan on 12/06/2007 02:50 pm
Post by: Chris Bergin on 12/06/2007 02:52 pm
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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!)
Post by: dember on 12/06/2007 02:55 pm
Post by: ShuttleDiscovery on 12/06/2007 02:59 pm
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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..
Post by: John2375 on 12/06/2007 03:05 pm
Post by: psloss on 12/06/2007 03:07 pm
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ShuttleDiscovery - 6/12/2007 10:59 AMGiven 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.Quotedember - 6/12/2007 3:55 PM
Hopefully they can get off the ground tomorrow.
Let's just hope the weather holds out..
Post by: John44 on 12/06/2007 03:07 pm
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=3181&Itemid=2
Post by: psloss on 12/06/2007 03:08 pm
Post by: shuttlefan on 12/06/2007 03:15 pm
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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. ;)
Post by: Lee Jay on 12/06/2007 03:18 pm
Post by: shuttlefan on 12/06/2007 03:18 pm
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Chris Bergin - 6/12/2007 9:52 AMQuoteshuttlefan - 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!! :)
Post by: psloss on 12/06/2007 03:23 pm
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Lee Jay - 6/12/2007 11:18 AMIn 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.)
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.
Post by: TrueBlueWitt on 12/06/2007 03:24 pm
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?
Post by: DaveS on 12/06/2007 03:29 pm
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psloss - 6/12/2007 5:23 PMQuoteLee Jay - 6/12/2007 11:18 AMIn 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.)
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.
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.
Post by: Chris Bergin on 12/06/2007 03:37 pm
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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.
Post by: Maverick on 12/06/2007 03:50 pm
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Super George - 6/12/2007 8:02 AMQuoteChris 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 ;)
Post by: Lee Jay on 12/06/2007 04:09 pm
Quote
DaveS - 6/12/2007 9:29 AMQuotepsloss - 6/12/2007 5:23 PMQuoteLee Jay - 6/12/2007 11:18 AMIn 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.)
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.
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.
Post by: Chandonn on 12/06/2007 04:15 pm
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...
Post by: Jorge on 12/06/2007 04:46 pm
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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.
Post by: John2375 on 12/06/2007 05:05 pm
Post by: on 12/06/2007 05:20 pm
Post by: Jim on 12/06/2007 05:22 pm
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Ray Todd - 6/12/2007 1:20 PM
What happens to the LOX and LH2 during the detanking? It is returned to the storage tanks and reused?
yes
Post by: punkboi on 12/06/2007 05:28 pm
*Sigh* The Launch Prevention Devices strike again...
And so much for having 4 straight launches this year that took off on the first attempt.
Post by: dember on 12/06/2007 05:29 pm
Post by: Joffan on 12/06/2007 05:33 pm
Post by: nathan.moeller on 12/06/2007 05:33 pm
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punkboi - 6/12/2007 12:28 PM*Sigh* The Launch Prevention Devices strike again...
And so much for having 4 straight launches this year that took off on the first attempt.
I'll take launch safety assurance over an first-try-four-times-in-a-row record any day.
Post by: nathan.moeller on 12/06/2007 05:37 pm
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Joffan - 6/12/2007 12:33 PM
Are these sensors actually used to determine when MECO should occur, under normal circumstances? (My recollection is that they are not a normal control point for launches, but are only a contingency for engine protection). If they are "contingency" sensors, how quickly does a true "dry" signal need to be acted on to protect the orbiter? Human speed, or quicker? Or if the consequences are less, like SSME damage but no orbiter effects, can they actually be ignored without threatening this mission (although possibly incurring costs for future)?
I don't believe they're used in normal scenarios, but I could be wrong. I say that because there has been a case of 'low-level cutoff' (STS-93) in which the ECO sensors went dry a little early in the ascent, resulting in a slight underspeed for Columbia. It would take a small fraction of a section to send and execute the shutdown command. And there aren't 'contingency' sensors. They only need two, but they have four for complete redundancy incase one or two fail on the way uphill. And we're not talking slight damage to SSMEs in the case of ECO sensor failure. We're talking catastrophic engine failure that would quickly and easily lead to orbiter damage or even destruction, I believe.
Post by: Jim on 12/06/2007 05:38 pm
Post by: leetdan on 12/06/2007 05:43 pm
Post by: mkirk on 12/06/2007 05:46 pm
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Joffan - 6/12/2007 12:33 PM
Are these sensors actually used to determine when MECO should occur, under normal circumstances? (My recollection is that they are not a normal control point for launches, but are only a contingency for engine protection). If they are "contingency" sensors, how quickly does a true "dry" signal need to be acted on to protect the orbiter? Human speed, or quicker? Or if the consequences are less, like SSME damage but no orbiter effects, can they actually be ignored without threatening this mission (although possibly incurring costs for future)?
Here is a very high level overview of how these ECO sensors work that I wrote for Interspacenews during the STS-114 timeframe.
http://www.interspacenews.com/interspace%20News%20Web%202/sections/In%20focus/ECO%20Sensors.htm
Bill Harwood wrote one for CBS/Spaceflight Now that is probably better to undersand than mine (since he writes much better than me) so if anyone knows where that link is feel free to post that here as well.
Mark Kirkman
Post by: JimO on 12/06/2007 05:51 pm
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mkirk - 6/12/2007 12:46 PM
Bill Harwood wrote one for CBS/Spaceflight Now that is probably better to undersand than mine (since he writes much better than me) so if anyone knows where that link is feel free to post that here as well.
Mark Kirkman
I thought I had, a few pages back...
Yup, here at 8:59 AM:
Harwood has put up a good historical background here:
http://spaceflightnow.com/shuttle/sts122/071206ecos/
Post by: mkirk on 12/06/2007 05:56 pm
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JimO - 6/12/2007 12:51 PMQuotemkirk - 6/12/2007 12:46 PM
Bill Harwood wrote one for CBS/Spaceflight Now that is probably better to undersand than mine (since he writes much better than me) so if anyone knows where that link is feel free to post that here as well.
Mark Kirkman
I thought I had, a few pages back...
Yup, here at 8:59 AM:
Harwood has put up a good historical background here:
http://spaceflightnow.com/shuttle/sts122/071206ecos/
Sorry JimO, as usuall I am late to the party.
;)
Mark Kirkman
Post by: Joffan on 12/06/2007 06:11 pm
(and Mark, your link leads back here...) (no longer... thanks again)
Post by: Yegor on 12/06/2007 06:13 pm
Post by: mkirk on 12/06/2007 06:15 pm
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Joffan - 6/12/2007 1:11 PM
Thanks for the answers guys. I guess the summary is: the ECO sensors wouldn't be used to determine actions in a perfectly nominal ascent, but if a tank runs dry early without engine cutoff, the rapid consequences could include loss of orbiter and crew.
(and Mark, your link leads back here...)
Sorry. I fixed it.
http://www.interspacenews.com/interspace%20News%20Web%202/sections/In%20focus/ECO%20Sensors.htm
Mark Kirkman
Post by: mkirk on 12/06/2007 06:16 pm
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Yegor - 6/12/2007 1:13 PM
When should we expect the next attempt to launch?
Just too soon to call, not enough data yet.
Tomorrow is very unlikely!!!
Mark Kirkman
Post by: nathan.moeller on 12/06/2007 06:19 pm
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Yegor - 6/12/2007 1:13 PM
When should we expect the next attempt to launch?
Last time something like this happened (STS-114) it took about two weeks before the next attempt. But it all depends on how fast they can find a source for the problem and resolve it. We'll just have to sit back and let them work their magic.
Post by: dember on 12/06/2007 06:21 pm
Post by: Yegor on 12/06/2007 06:22 pm
Post by: nathan.moeller on 12/06/2007 06:23 pm
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dember - 6/12/2007 1:21 PM
What about STS-115?
STS-115 had so many delays I honestly can't remember what happened with the ECO sensors for that flight. I think it resolved itself but someone else will have to elaborate.
Post by: nathan.moeller on 12/06/2007 06:23 pm
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Yegor - 6/12/2007 1:22 PM
Thank you very much for quick answers! :)
Our pleasure :) All part of the NSF community.
Post by: psloss on 12/06/2007 06:26 pm
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dember - 6/12/2007 2:21 PMIn that case, they followed the procedure agreed upon after STS-114, which was to detank and then retank the next day. None of the circuits failed WET on the second attempt and they launched.
What about STS-115?
This situation isn't exactly the same as two of the LH2 ECO measurements are showing this behavior; in the previous launch attempt cases, only one measurement failed WET.
Post by: Zoomer30 on 12/06/2007 06:37 pm
Its like a PC. One day it acts up, you dont do anything to fix it, the next try its fine...huh? I remember thats what they did the last time the ECOs failed wet. Just try again and hope for the best.
Post by: Zoomer30 on 12/06/2007 06:40 pm
Post by: nathan.moeller on 12/06/2007 06:41 pm
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Zoomer30 - 6/12/2007 1:37 PM
I dont get how on one try the ECOs dont work and then next try they do. Seems a little odd. Such an important part needs to work 100% of the time. Running out of gas in a car is inconvinent. Running out of gas on the shuttle is deadly (the turbo pumps spin out of control).
Its like a PC. One day it acts up, you dont do anything to fix it, the next try its fine...huh? I remember thats what they did the last time the ECOs failed wet. Just try again and hope for the best.
It's a pretty complex little piece of equipment. And some believe the problem isn't in the sensors themselves. Some think it's related to connections between the sensors and the orbiter avionics. Very, very complex.
Post by: Jim on 12/06/2007 06:46 pm
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Zoomer30 - 6/12/2007 2:40 PM
Would be nice if there was some sort of test they could run in the VAB BEFORE they rolled out and all that to find out before that the ECOs where toast. Makes me worry about the CEV Stick and the LEV Launcher, they will probably have the same sensors!
They won't
Post by: dember on 12/06/2007 06:49 pm
Post by: Zoomer30 on 12/06/2007 06:50 pm
That article ECO SENSORS 101 explains the issue well. Reading that makes me wonder if we should even be flying with such a touchy and important item that has an issue that just cant be explained. From that ECO 101 article it seems the sensors could fail dry and shut the engines off way early, or fail wet and run out of fuel or O2. Run out of fuel and you have a oxygen rich issue, lots of fire risk. The other way and you have turbo pump cavitation, they go from normal speed to who knows how fast in the blink of an eye and come apart.
Post by: Chris Bergin on 12/06/2007 06:53 pm
Post by: psloss on 12/06/2007 06:53 pm
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Zoomer30 - 6/12/2007 2:50 PMThat's why they have four of them on both sides.
From that ECO 101 article it seems the sensors could fail dry and shut the engines off way early, or fail wet and run out of fuel or O2. Run out of fuel and you have a oxygen rich issue, lots of fire risk. The other way and you have turbo pump cavitation, they go from normal speed to who knows how fast in the blink of an eye and come apart.
Post by: nathan.moeller on 12/06/2007 06:57 pm
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dember - 6/12/2007 1:49 PM
It would make it easier if they could run tests.
They do run tests. They run tests several times during the launch countdown. You have to fill the tank to truly test these things out. That way they can run simulated dry commands and make sure they're functioning properly. It won't help you much to run tests when the tank is empty. You'll be making sure they'll show 'dry' when it's really dry. But you have to make sure it'll will also show 'wet' when it's loaded. It HAS to work both ways, and the only way to try it out is by filling the tank on launch day. If it works, great. If not, find the problem, fix it and try again.
This sort of thing happens, people. This is how they've approached this sort of problem before and, just like all the others, they'll get it fixed for STS-122. Let's quit questioning/criticizing their methods and let them do their jobs. For all we know, they could try tomorrow and everything could work fine. Just sit back and enjoy the ride.
Post by: nathan.moeller on 12/06/2007 06:59 pm
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psloss - 6/12/2007 1:53 PMQuoteZoomer30 - 6/12/2007 2:50 PMThat's why they have four of them on both sides.
From that ECO 101 article it seems the sensors could fail dry and shut the engines off way early, or fail wet and run out of fuel or O2. Run out of fuel and you have a oxygen rich issue, lots of fire risk. The other way and you have turbo pump cavitation, they go from normal speed to who knows how fast in the blink of an eye and come apart.
It's also why they have four instead of the required two. If something goes wrong with one, or even two, sensors, they have complete redundancy to pick up the slack.
Post by: Chris Bergin on 12/06/2007 07:17 pm
Post by: Joffan on 12/06/2007 07:23 pm
This means to me that if the Shuttle team does decide to have another try tomorrow, and the sensors show good in the tests, we can have a high level of confidence in that result.
(ETA: I'm counting the whole signal path as part of the sensor here).
Post by: marshallsplace on 12/06/2007 07:28 pm
Post by: jacqmans on 12/06/2007 07:35 pm
Post by: mkirk on 12/06/2007 07:35 pm
I am sure nobody is surprised.
Mark Kirkman
Post by: kimmern123 on 12/06/2007 07:55 pm
Post by: Chris Bergin on 12/06/2007 07:56 pm
Really not sure how the FD is thinking this is looking good for tomorrow, but we'll see what the MMT say.
MMT on a break, about to head back in.
Post by: mhellesen on 12/06/2007 08:00 pm
http://www.msnbc.msn.com/id/22120058/
Anyone else hearing this?
Post by: Chris Bergin on 12/06/2007 08:02 pm
"Anonymous sources" will be engineers etc..the same sort of thing we work off. You can't go naming sources.
Post by: psloss on 12/06/2007 08:03 pm
Post by: Ford Mustang on 12/06/2007 08:05 pm
Post by: psloss on 12/06/2007 08:49 pm
Post by: Bubbinski on 12/06/2007 08:55 pm
Post by: psloss on 12/06/2007 08:57 pm
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Bubbinski - 6/12/2007 4:55 PMNo...and FWIW, they switched to a live pad shot on NASA TV...
The "beanie cap" removal....is that a sign the RSS will be rolled back?
Post by: Ford Mustang on 12/06/2007 09:04 pm
NASA TV had a nice promo of Columbus.. Grabbed some snaps:
Post by: Ford Mustang on 12/06/2007 09:11 pm
EDIT: They've either opened the iris on the camera.. or something..
Post by: rdale on 12/06/2007 09:12 pm
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Ford Mustang - 6/12/2007 5:04 PM
Not sure if these can go here, so mods feel free to delete if they aren't..
NASA TV had a nice promo of Columbus.. Grabbed some snaps:
It was nice to see - John44 has it on his site...
Post by: Chris Bergin on 12/06/2007 09:19 pm
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psloss - 6/12/2007 9:49 PM
Briefing now NET 5:30 pm Eastern...
I reckon it'll be later, as MMT is still meeting and has a way to go yet.
Post by: Ford Mustang on 12/06/2007 09:27 pm
Post by: psloss on 12/06/2007 09:28 pm
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Chris Bergin - 6/12/2007 5:19 PMJust passing along the updates as I see them on NASA TV...which just showed the GOX vent arm being swung back over to the tank.Quotepsloss - 6/12/2007 9:49 PM
Briefing now NET 5:30 pm Eastern...
I reckon it'll be later, as MMT is still meeting and has a way to go yet.
Post by: psloss on 12/06/2007 09:30 pm
Post by: Ford Mustang on 12/06/2007 09:30 pm
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Chris Bergin - 6/12/2007 5:19 PMQuotepsloss - 6/12/2007 9:49 PM
Briefing now NET 5:30 pm Eastern...
I reckon it'll be later, as MMT is still meeting and has a way to go yet.
NET 6:00 PM EST.
Post by: Chris Bergin on 12/06/2007 09:48 pm
Post by: Lee Jay on 12/06/2007 09:50 pm
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Chris Bergin - 6/12/2007 3:48 PM
NET 6:30pm and could be later.
So where are we? Are the teams currently performing the 24 hour scrub-turnaround procedures while waiting for the MMT to conclude?
Post by: collectSPACE on 12/06/2007 09:51 pm
Post by: psloss on 12/06/2007 09:53 pm
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Lee Jay - 6/12/2007 5:50 PMThat was the last report. The launch team is preserving the option of tanking tomorrow, but I think some people are inferring (incorrectly) that means they will tank tomorrow. Haven't seen a report of any decisions out of the MMT yet.QuoteChris Bergin - 6/12/2007 3:48 PM
NET 6:30pm and could be later.
So where are we? Are the teams currently performing the 24 hour scrub-turnaround procedures while waiting for the MMT to conclude?
Post by: el_nino on 12/06/2007 09:58 pm
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collectSPACE - 6/12/2007 5:51 PM
Even when she's grounded, Atlantis is a beautiful bird... (taken about an hour ago during an unexpected photo opp organized by KSC PAO).
AWESOME photo. Got a high res shot of that around anywhere?
Post by: psloss on 12/06/2007 09:59 pm
Post by: Ford Mustang on 12/06/2007 10:00 pm
Also, photos from the photo-opp about an hour ago now in the KSC Hot Pics gallery.
http://mediaarchive.ksc.nasa.gov/search.cfm?cat=4
Post by: collectSPACE on 12/06/2007 10:25 pm
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el_nino - 6/12/2007 4:58 PMThanks! E-mail or PM me about the high-res...
AWESOME photo. Got a high res shot of that around anywhere?
Post by: Felix on 12/06/2007 10:26 pm
http://www.nasa.gov/images/content/122586main_ECO_charts1.JPG
http://www.nasa.gov/images/content/122588main_ECO_charts3.JPG
http://www.nasa.gov/images/content/122589main_ECO_charts4.JPG
Post by: Chris Bergin on 12/06/2007 10:26 pm
Post by: Ford Mustang on 12/06/2007 10:27 pm
EDIT: You got me, Chris. :laugh:
Post by: mkirk on 12/06/2007 10:46 pm
Mark Kirkman
Post by: erioladastra on 12/06/2007 10:51 pm
Post by: Chris Bergin on 12/06/2007 10:51 pm
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erioladastra - 6/12/2007 11:51 PM
No launch attempt tomorrow.
Tanking Test instead, right? (EDIT, doesn't look like it).
Post by: mkirk on 12/06/2007 10:53 pm
P.S.
Briefers probably diverted to the LCC cafeteria before heading across the street to the Press Site... :)
Mark Kirkman
Post by: Chris Bergin on 12/06/2007 10:55 pm
Post by: Lee Jay on 12/06/2007 10:58 pm
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Chris Bergin - 6/12/2007 4:55 PM
MMT tomorrow to decide on new launch date. NET Saturday, may be later.
If tomorrow is a definite no-go, would they have time to top-off cyro before a hypothetical Saturday attempt?
Post by: ras391 on 12/06/2007 11:00 pm
Post by: DaveS on 12/06/2007 11:12 pm
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Lee Jay - 7/12/2007 12:58 AMDepends on whether they have decided to perform a tanking test or not. They can't perform a tanking test if the RSS is around the vehicle.QuoteChris Bergin - 6/12/2007 4:55 PM
MMT tomorrow to decide on new launch date. NET Saturday, may be later.
If tomorrow is a definite no-go, would they have time to top-off cyro before a hypothetical Saturday attempt?
Post by: GioFX on 12/06/2007 11:13 pm
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Lee Jay - 7/12/2007 12:58 AMIf tomorrow is a definite no-go, would they have time to top-off cyro before a hypothetical Saturday attempt?AFAIK they have 3 consecutive attempts before having to refill the APUs...
Post by: DaveS on 12/06/2007 11:14 pm
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GioFX - 7/12/2007 1:13 AMNot the APUs(Auxillary Power Units)! The Power Reactant Storage and Distribution(PRSD) system storage spheres beneath the payload bay.QuoteLee Jay - 7/12/2007 12:58 AMIf tomorrow is a definite no-go, would they have time to top-off cyro before a hypothetical Saturday attempt?AFAIK they have 3 consecutive attempts before having to refill the APUs...
Post by: GioFX on 12/06/2007 11:16 pm
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DaveS - 7/12/2007 1:14 AMNot the APUs(Auxillary Power Units)! The Power Reactant Storage and Distribution(PRSD) system storage spheres beneath the payload bay.Yep sorry, i misunderstood the question!
Post by: on 12/06/2007 11:17 pm
Post by: Felix on 12/06/2007 11:18 pm
Post by: DaveS on 12/06/2007 11:18 pm
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Justin Wheat - 7/12/2007 1:17 AM40% according to the L-1 day Wx forecast. And there's a dedicated launch weather thread with all this info already!
What is the percent of KSC weather prohibiting the launch Saturday?
Post by: Chris Bergin on 12/06/2007 11:20 pm
Post by: shuttlefan on 12/06/2007 11:21 pm
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DaveS - 6/12/2007 6:12 PMQuoteLee Jay - 7/12/2007 12:58 AMDepends on whether they have decided to perform a tanking test or not. They can't perform a tanking test if the RSS is around the vehicle.QuoteChris Bergin - 6/12/2007 4:55 PM
MMT tomorrow to decide on new launch date. NET Saturday, may be later.
If tomorrow is a definite no-go, would they have time to top-off cyro before a hypothetical Saturday attempt?
Theoretically, couldn't they do what they did with the second STS-114 attempt tomorrow, tank and see how the sensors perform and then if they work, proceed with the rest of the countdown. I remember some folks calling STS-114's second attempt sort of a tanking test embedded into a real launch count. ;)
Post by: DaveS on 12/06/2007 11:24 pm
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shuttlefan - 7/12/2007 1:21 AMIt wasn't a tanking test, it was a real launch countdown from the get go. Embedding a tanking test into the launch countdown was just one of the many ideas thrown around at the time.
Theoretically, couldn't they do what they did with the second STS-114 attempt tomorrow, tank and see how the sensors perform and then if they work, proceed with the rest of the countdown. I remember some folks calling STS-114's second attempt sort of a tanking test embedded into a real launch count. ;)
Post by: Felix on 12/06/2007 11:35 pm
Post by: Chris Bergin on 12/06/2007 11:40 pm
48 hour scrub turnaround confirmed. NET Saturday.
Post by: psloss on 12/06/2007 11:43 pm
Post by: psloss on 12/06/2007 11:43 pm
Post by: psloss on 12/06/2007 11:45 pm
Post by: Chris Bergin on 12/06/2007 11:47 pm
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psloss - 7/12/2007 12:43 AM
"What we did, fundamentally, was to keep all our options in front of us." "We need some more time."
Given what the ET guys were saying earlier, Leroy's made totally the right call.
Post by: psloss on 12/06/2007 11:48 pm
Post by: psloss on 12/06/2007 11:49 pm
Post by: Ford Mustang on 12/06/2007 11:50 pm
40% chance of KSC weather prohibiting launch on Saturday.
Post by: psloss on 12/06/2007 11:54 pm
Post by: psloss on 12/06/2007 11:56 pm
The haven't used the voltage measurements during ascent, but have been thinking about it. Now the flight control team is trying to see if and how they could use that.
Post by: psloss on 12/07/2007 12:01 am
Post by: Chris Bergin on 12/07/2007 12:02 am
Post by: psloss on 12/07/2007 12:07 am
(And "breaking the flight configuration" wouldn't support the option to attempt on Saturday.)
Post by: Chris Bergin on 12/07/2007 12:08 am
Post by: psloss on 12/07/2007 12:10 am
Post by: Chris Bergin on 12/07/2007 12:11 am
Post by: psloss on 12/07/2007 12:13 am
Post by: psloss on 12/07/2007 12:17 am
Post by: psloss on 12/07/2007 12:18 am
Post by: Chris Bergin on 12/07/2007 12:20 am
Post by: mkirk on 12/07/2007 12:20 am
While there has been some simulation on this for the ascent flight control team it is no trivial thing to get the procedures formalized and documented to the level you want before you go fly.
I may be wrong but at this point the ascent flight procedures with the ECO mod are not nearly mature enough.
I can see them getting there (i.e. to 2 of 4 decision) I am just saying that I dont believe they can do that in the 48 hour time frame!!!!
Mark Kirkman
Post by: mkirk on 12/07/2007 12:27 am
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Gary - 6/12/2007 7:24 PMQuotemkirk - 7/12/2007 1:20 AM
While there has been some simulation on this for the ascent flight control team it is no trivial thing to get the procedures formalized and documented to the level you want before you go fly.
I'd also assume this is something you would want to throw at the crew and misson control in the sims a few times so everyone knows the signature of a ECO sensor issue and a (nearly) empty tank.
It does sound like its an option that's under evaulation but hasn't actually borne fruit yet.
I honestly don't know if this was presented in any of the Ascent Integrated Sims for 118 or subsequent training flows. Even if it did get worked in those I still think it would take the Program past Saturday to get everyone onboard with the new philosophy and to have the procedures and flight rules properly documented. (reference my previous post)
Mark Kirkman
Post by: psloss on 12/07/2007 12:29 am
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mkirk - 6/12/2007 8:27 PMDo you think it would be possible to get that through an organization the size of the SSP in a week's time? (i.e., before the end of the December window)
I honestly don't know if this was presented in any of the Ascent Integrated sims for 118 or subsequent training flows. Even if it did get worked in those I still think it would take the program past Saturday to get everyone onboard with the new philosophy and to have the procedures and flight rules properly documented. (reference my previous post)
Post by: Ford Mustang on 12/07/2007 12:33 am
[small]Also, if this isn't supposed to go here yet, please delete[/small]
Post by: mkirk on 12/07/2007 12:34 am
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psloss - 6/12/2007 7:29 PMQuotemkirk - 6/12/2007 8:27 PMDo you think it would be possible to get that through an organization the size of the SSP in a week's time? (i.e., before the end of the December window)
I honestly don't know if this was presented in any of the Ascent Integrated sims for 118 or subsequent training flows. Even if it did get worked in those I still think it would take the program past Saturday to get everyone onboard with the new philosophy and to have the procedures and flight rules properly documented. (reference my previous post)
I would hate to speculate much further than what I already have. The team is great at doing the seemingly impossible, and right now the leader ship is outstanding...so we will just have to wait and see.
My main motive for the previous couple of posts was to point out the enormity of what has to take place. Going with a flight rationale of 2 of 4 ( or something similar) based on the real time use of the new instrumentation is not as simple as it may have sounded to some of the listeners to the briefing.
Mark Kirkman
Post by: Gary on 12/07/2007 12:36 am
Post by: erioladastra on 12/07/2007 01:06 am
It is no different than pulling together the solar array repair EVA on 10A. We can do it. It won't be easy but it could be done.
Post by: STSFan10 on 12/07/2007 01:17 am
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erioladastra - 6/12/2007 8:06 PM
"I would hate to speculate much further than what I already have. The team is great at doing the seemingly impossible, and right now the leader ship is outstanding...so we will just have to wait and see. "
It is no different than pulling together the solar array repair EVA on 10A. We can do it. It won't be easy but it could be done.
Preaching to the converted on a pro-NASA, pro-Shuttle site like this. :cool:
Awesome coverage here again.
Post by: MKremer on 12/07/2007 01:28 am
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Ford Mustang - 6/12/2007 7:33 PM
Looks like a set of Xenon lights are on... Wondering when RSS moves to MATE position, if anyone knows.. I've been away for most of the briefing...
No specific time specified. I imagine they'll start whenever everything is finally ready for the rotation to begin, and only those on the pad will know that.
Post by: Michael22090 on 12/07/2007 01:36 am
rtsp://163.205.10.22:8080/encoder/cif.rm
Post by: Ford Mustang on 12/07/2007 02:06 am
Quote
Michael22090 - 6/12/2007 9:36 PM
Just so everyone knows, there is a live streaming view of the pad at this link. It is Camera 060, and it should be a very interesting view for the RSS retract later on. Xenons are on too, so its very easy to see everything.
rtsp://163.205.10.22:8080/encoder/cif.rm
Thanks for that link. If they rotate the RSS while I'm watching, then I'll record it via cam record, as I can't think of any other way to record it.. All my other options are out! :(
Post by: jimvela on 12/07/2007 02:15 am
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psloss - 6/12/2007 6:13 PM
Craig Covault asking a configuration management question -- does OV-104 or the tank have a different config? Leroy Cain said that OV-105 and OV-103 (on STS-118 and STS-120, respectively) have already flown in the config that OV-104 is in (which flew a "hybrid" config on STS-117). Can't rule out the possibility that wiring config is a contributing cause.
You have sensors that are known to work when tested individually, a point sensor box that works when tested individually, how can this be anything but some sort of signal path problem?
Post by: Andy L on 12/07/2007 03:05 am
Post by: Firestarter on 12/07/2007 03:22 am
Quote
Andy L - 6/12/2007 10:05 PM
Read through the thread, great catch up and really great work with the news, even when some other sites were saying different things, though it's the norm for this site to be on top of the game. Great to have these threads live, but also as a catch up for those of us who were at work with no net access. Thanks again.
Well said.
Just shows how it all has to come together for launch, as this was a very smooth processing flow until this happened. Shows how well they did to get three launches off on the first attempt prior to this.
Post by: blueguitarbob on 12/07/2007 03:34 am
Post by: JimO on 12/07/2007 04:36 am
Quote
mkirk - 6/12/2007 7:27 PM
I honestly don't know if this was presented in any of the Ascent Integrated Sims for 118 or subsequent training flows. Even if it did get worked in those I still think it would take the Program past Saturday to get everyone onboard with the new philosophy and to have the procedures and flight rules properly documented. (reference my previous post)
Mark Kirkman
The Booster console team apparently already has prepared a fairly mature draft of the FR's for handling ECO votes when they are known to be 'fail wet' (based on the new instrumentation). They're probably reviewing all sim and analysis experience as we type, and will prepare their pitch tomorrow morning. If they can demonstrate that their decision tree or flow chart representation, needed for fast look-up during time-critical ascent, actually correctly responds to all possible permutations, they ought to be able to get it approved at the MMT.
I don't think the crew is deeply involved -- these FR's are all for MCC calls, and the crew just has to be aware of the range of keyboard inputs or switch throws they may be called upon to make.
I served as Neil Hutchison's panel secretary in 1979-1980 when he kicked off the very FIRST 'Shuttle Ascent Flight rules' panel meetings, and I documented the rationales, reasoning, and disagreements for the record and for wider distribution. Then I was on Neil's 'Silver Team' -- the very first shuttle Ascent Shift -- that made it all work on April 12, 1981, at the OMS/RCS Propulsion console. For all our prep, what a bold leap into the unknown THAT morning was.
And no, NONE of us was watching TV of the liftoff. We had our data screens to concentrate on.
Post by: Zoomer30 on 12/07/2007 05:45 am
So really the only times it would have been used would have been STS -51F (the Challenger ATO) and the Columbia Chandra mission. If memory serves the ECOs did their job on that day, with engine 3 leaking hydrogen all the way up, the engines used up the oxygen and the ECOs called for an very slight early MECO.
Post by: Ronsmytheiii on 12/07/2007 05:50 am
Post by: avollhar on 12/07/2007 07:41 am
Reading the front page article of nasaspaceflight.com, also ECO #1 looks buggy (sensing briefly WET, when the tank is empty), so there seems to be a generic problem. This is a safety issue and I cannot believe that people are even thinking launching as-is, when 3 of 4 sensors are behaving strangely.
Sad to see again, that schedule goes over safety.
Post by: mr.columbus on 12/07/2007 07:48 am
Quote
avollhar - 7/12/2007 3:41 AM
...when 3 of 4 sensors are behaving strangely.
Well, one works fine, so I say GO! No, seriously, you are right - it is a bit of a mystery to me as well, why NASA and people around here are again in a GO fever. Of course there is schedule pressure, but I thought that schedule should not have any influence on critical safety decisions any more.
Post by: Analyst on 12/07/2007 08:00 am
Quote
mr.columbus - 7/12/2007 9:48 AM
No, seriously, you are right - it is a bit of a mystery to me as well, why NASA and people around here are again in a GO fever. Of course there is schedule pressure, but I thought that schedule should not have any influence on critical safety decisions any more.
I agree. If an engine running dry will behave badly - as many people here have indicated - and this is the reason for the ECO sensors being there in the first place, they should work.
Are the ECO sensors the last line of defense or are there other systems?
When into the flight start the computers accepting data from the sensors? I would think only well into the flight, because a dry signal at T+60 seconds would clearly be wrong and a resulting shutdown probably as worse as a dry running engine.
Analyst
Post by: DaveS on 12/07/2007 08:14 am
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Analyst - 7/12/2007 10:00 AMThey're armed at a specific velocity which is different for the various abort modes. Usually that velocity isn't reached until about 8 minutes into the ascent.
When into the flight start the computers accepting data from the sensors? I would think only well into the flight, because a dry signal at T+60 seconds would clearly be wrong and a resulting shutdown probably as worse as a dry running engine.
Analyst
Post by: psloss on 12/07/2007 10:06 am
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Analyst - 7/12/2007 4:00 AMMark Kirkman (mkirk) wrote a good overview of the ECOs, which I think has already been linked in this thread; but here it is again:
Are the ECO sensors the last line of defense or are there other systems?
When into the flight start the computers accepting data from the sensors? I would think only well into the flight, because a dry signal at T+60 seconds would clearly be wrong and a resulting shutdown probably as worse as a dry running engine.
http://www.interspacenews.com/interspace%20News%20Web%202/sections/In%20focus/ECO%20Sensors.htm
Excerpt:
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During a normal launch the shuttles computers are monitoring the orbiters velocity for the shutdown cue. For STS-114 the desired MECO velocity target is 25,819 feet per second (this is equivalent to 17,603 miles per hour) at the point of zero engine thrust. The shutdown process takes about six seconds during which time the shuttle is still accelerating. So in order to achieve a zero thrust target of 25,819 fps, the actual MECO command will be sent at a velocity cue of 25,800 feet per second. For normal ascents the engine cutoff sensors have no role in shutting down the main engines. Velocity is the only shutdown cue. In fact the GPCs will not even accept a shutdown command from the ECO sensors unless they have been armed.
The command to arm the ECO sensors is issued only if one of the following conditions applies:
- Two engines have failed, or
- A flight specific arming mass has been reached. This mass is usually the total mass of propellant remaining in the external tank that provides the shuttle the ability to perform a Transoceanic Abort Landing (TAL) should the sensors issue a cutoff command immediately upon arming. For STS-114 this mass is about 32000 pounds of propellant remaining.
L2 plug: if you review the STS-93 ascent video, you can hear that event called out on one of the booster console's loops.
Post by: psloss on 12/07/2007 10:32 am
http://www.cbsnews.com/network/news/space/current.html
Post by: dember on 12/07/2007 11:23 am
Post by: ETEE on 12/07/2007 11:23 am
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avollhar - 7/12/2007 8:41 AM
Sorry to say this, but weakening the ECO fuel gauges flight rules is not what these rules are for. I see here a clear push to get the shuttle off the pad in December. The proper way to do it would be to stand down and check the complete wiring from ECO to point sensor box, even if this involves opening the engine compartment.
Reading the front page article of nasaspaceflight.com, also ECO #1 looks buggy (sensing briefly WET, when the tank is empty), so there seems to be a generic problem. This is a safety issue and I cannot believe that people are even thinking launching as-is, when 3 of 4 sensors are behaving strangely.
Sad to see again, that schedule goes over safety.
I couldn't agree more. I was staggered to see Leroy Cain in "launch in December at all costs" mode. He is deferring to the current safety risk assessment but there is obviously a huge management attempt to ease flight rules that already have been relaxed once before.
IMO there is a clear indication of a wiring fault with one of the sensors that failed, which was stuck on wet, that reset to a dry indication some hours after detanking. If that is a fault due to cryogenic cooling causing an open circuit in wiring or connectors, then it should be fixed before flight unless it is the only faulty sensor.
The whole sensor system in the ET seems to be troublesome and pretending to ignore this is not the way to operate flight critical hardware.
Post by: mark147 on 12/07/2007 12:01 pm
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montmein69 - 7/12/2007 11:09 AMWhat they said at the briefing was that the new instrumentation allows them to tell whether a sensor has failed in the WET state or whether it is reporting a normal WET condition. Before the new instrumentation was fitted, they could test this before launch by simulating a DRY condition but not after T-0.
If 2 of 4 are failing .... how do you know that the other 2 are right ?
What is the "new instrumentation" procedure ? (which way to get the correct data ?)
Without the new instrumentation, they had no way of telling if any sensors fail after they've finished the pre-flight checks, so they need some redundancy to make sure that the cut off can will happen in the event of LH2 exhaustion. Now, with the new instrumentation, they can tell if any sensors subsequently fail.
They might use this mechanism to permit a launch with two failed sensors on the basis that they would know if a third fails. If the third does fail, they've lost the safety ECO function but could choose to do a manual shutdown as a precaution to protect the vehicle and crew. The cost would be that they would then have an abort condition which would mean a TAL, AOA or ATO, none of which would get Columbus attached to the station and two of which would create delay in getting Atlantis back to KSC (considerably so in the case of a TAL!).
They can trade crew safety against the risk to the programme (due to an abort) but the cost is there in one or the other. Those are no doubt the issues they will be working through today.
Mark
Post by: on 12/07/2007 12:02 pm
Post by: dember on 12/07/2007 12:09 pm
Post by: psloss on 12/07/2007 12:12 pm
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ETEE - 7/12/2007 7:23 AMI couldn't agree less with this interpretation of what Leroy Cain said last night. The way I parsed what he said last night was that they are approaching the current situation making minimum assumptions, and they have made zero decisions other than passing on an attempt today.
I couldn't agree more. I was staggered to see Leroy Cain in "launch in December at all costs" mode.
I don't understand the blind jumping to the conclusion that IF the program deliberates whether they can proceed that somehow implies that they will proceed.
Evaluating one's options doesn't seem rash to me, because there's no commitment, no decision.
What is the basis for the assumption that they can't fly in December? If you make that assumption, what is it based on?
If you are questioning their philosophy of considering all their options, what is the basis for that?
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ETEE - 7/12/2007 7:23 AMWhat makes the indication "clear?" Just because you can detect an anomaly, does it follow that you know the cause of the anomaly?
IMO there is a clear indication of a wiring fault with one of the sensors that failed, which was stuck on wet, that reset to a dry indication some hours after detanking. If that is a fault due to cryogenic cooling causing an open circuit in wiring or connectors, then it should be fixed before flight unless it is the only faulty sensor.
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ETEE - 7/12/2007 7:23 AMWhat's the basis for this? You realize that a significant portion of this particular sensor circuit is in the orbiter, right?
The whole sensor system in the ET seems to be troublesome and pretending to ignore this is not the way to operate flight critical hardware.
Post by: Andrewwski on 12/07/2007 12:30 pm
Nobody but the MMT and people working on this are qualified to say what is OK and what is not.
Post by: rfoshaug on 12/07/2007 12:32 pm
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Gary - 7/12/2007 1:15 PMQuotemontmein69 - 7/12/2007 11:09 AM
Has ESA any say in the matter ? (two astronauts in the crew and Columbus in the bay)
Any say over what? ESA can't force NASA to launch.
I think montmein69 meant if ESA could refuse to launch with their astronauts and their cargo if they are not comfortable with the safety situation.
My opinion is that ESA do not know the details of the inner workings of the shuttle system. NASA and USA do, and when ESA originally decided to lift their cargo and astronauts to orbit on the shuttle, they entrusted that cargo and those astronauts to the engineers and managers of the shuttle program.
I see no reason why ESA should not trust any decision made by shuttle managers and engineers, whether it is to fly as is or to roll back and fix the problem.
Post by: mark147 on 12/07/2007 12:40 pm
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Gary - 7/12/2007 1:30 PMThe sensors aren't armed until they can make a TAL site [as I see you've spotted from your edit]. Also, they seem to have some confidence that the failures they're seeing are failures to the WET state due to an open circuit somewhere. But, I expect they're weighing up the likelihood of other failures in the risk calculations.
Even with two failed sensors you are on a fine line. If the other two fail and show DRY you are into engine shutdown and a very bad day.
It seems too risky to me to go with two failed sensors but NASA have a lot more information on which to base a decision than I do. I'm sure if they do make a launch attempt they will do it having considered all the possible scenarios. If I had to place a bet, I'd bet against them launching on Saturday if they still have two failed sensors but that's just my opinion.
M.
Post by: psloss on 12/07/2007 12:44 pm
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Gary - 7/12/2007 8:30 AMWhat's the difference between that and a TAL? The entry heating in some types of TAL aborts can be more severe than a normal entry.
AOA is the worst condition you can be in - You put the crew into a full re-entry regime without the benefit of the FD2 OBSS scans.
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Gary - 7/12/2007 8:30 AMI wouldn't jump to that conclusion about an abort -- for example, if you want to play the press/political angle, the OUTCOME of the abort would be important. (As well as the cause.)
Absolutely. I firmly believe ANY abort will signal an end to the shuttle there and then.
EDIT TO ADD: Shuttle Q & A part 4 states the ECO sensors aren't armed until TAL regime of flight so that means RTLS is an open option even with faulty ECO sensors.
I don't understand the linkage between the ECO sensors and RTLS. If you cut all three engines that early in ascent you might go to OPS 6, but it's a contingency abort.
Post by: Analyst on 12/07/2007 12:46 pm
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psloss - 7/12/2007 2:12 PM
What is the basis for the assumption that they can't fly in December? If you make that assumption, what is it based on?
I pick one quote to illustrate the "problem". People (including me sometimes) jump to conclusions pretty fast, see anologies even if there aren't any and question things. This thinking is not bad in general. But with the limited information we have, conclusion are often simply wrong. There is the moderate majority of people and two more "extreme" camps:
- Some cry "rollback" whenever a switch is in the wrong positon,
- others want to launch even if the engines don't ignite.
The first group always sees "go fever", the second group is surrounded by risk adverse people.
I for myself hear the word "rollback" quite to often, which puts me into the direction of the second group, but still quite in the middle I believe :) Of course a rollback is always possible, but this does not mean it will happen. A few weeks ago Chris started a thread about the RCS valve problem with "potentially rollback". While this has been true, my thought was "pretty hard words" for a problem not well understood then. A rollback is always *possible*. Doesn't mean there will be one.
Hope this does not confuse things even more. :)
Analyst
Post by: cabbage on 12/07/2007 12:50 pm
So the sensors indicating DRY would not result in a MECO in a zone where no intact abort was available - they would just be ignored and the interpretation as a "very bad day" is incorrect.
However, I think you're right to say that an intact abort would be a serious event for the shuttle programme (downtime to revisit ECO sensor issues) and a big logistics issue for the ISS. I personally don't think ending the shuttle programme early would be a proportionate response to a single systems failure that resulted in an abort. (ISTM that the shuttle *systems* (logic, electronics, computers, machinery) have not been safety issues, and were not a factor in either of the two accidents - they have been caused by issues of materials, construction and management)
edit: Ah, others got there first.
Post by: psloss on 12/07/2007 12:56 pm
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Andrewwski - 7/12/2007 8:30 AMFor the most part; I'm sure there are other rocket scientists who would be qualified. What I've observed over the years is very little public speculation from that community in these situations.
Couldn't agree more, Philip. This isn't "go fever".
Nobody but the MMT and people working on this are qualified to say what is OK and what is not.
For us outsiders, here's the thing about whether it's go fever or not: we won't be able to determine that until AFTER the fact unless someone goes public in an unprecedented way.
Post by: Chris Bergin on 12/07/2007 01:24 pm
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Analyst - 7/12/2007 1:46 PM
A few weeks ago Chris started a thread about the RCS valve problem with "potentially rollback". While this has been true, my thought was "pretty hard words" for a problem not well understood then. A rollback is always *possible*. Doesn't mean there will be one.
Analyst
So you don't want us to report the *facts* about the options open to managers evaluating status? Fact of the matter is, had the valve been the failure point, then yes, rollback would have been an option as the valve could not of been R&Red at the pad. The other option was to fly as-is with waivers, which we also reported. Thankfully, as written, we followed the process (do we hold back the information until after the event??) the issue was being caused downstream and was corrected.
We're not going to sugarcoat facts, and we sure as hell aren't going to be reporting the style of "can't tell you yet....we'll tell you more after the event". You're on the wrong site if so, as we report live status, as we all follow the process.
We'll be doing that today, from the options of launching tomorrow, delaying, or rollback. Whatever the MMT is evaluating, we'll be reporting it, regardless if it's "harsh words" or not. Facts are facts.
Post by: haywoodfloyd on 12/07/2007 01:32 pm
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Chris Bergin - 7/12/2007 9:24 AMQuoteAnalyst - 7/12/2007 1:46 PM
A few weeks ago Chris started a thread about the RCS valve problem with "potentially rollback". While this has been true, my thought was "pretty hard words" for a problem not well understood then. A rollback is always *possible*. Doesn't mean there will be one.
Analyst
So you don't want us to report the *facts* about the options open to managers evaluating status? Fact of the matter is, had the valve been the failure point, then yes, rollback would have been the call as the valve could not of been R&Red at the pad. Thankfully, as written, as we followed the process (do we hold back the information until after the event??) the issue was being caused downstream and was corrected.
We're not going to sugarcoat facts, and we sure as hell aren't going to be reporting the style of "can't tell you yet....we'll tell you more after the event". You're on the wrong site if so, as we report live status, as we all follow the process.
We'll be doing that today, from the options of launching tomorrow, delaying, or rollback. Whatever the MMT is evaluating, we'll be reporting it, regardless if it's "harsh words" or not. Facts are facts.
As it should be, Chris.
Well said.
Post by: shuttlefan on 12/07/2007 01:32 pm
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Chris Bergin - 7/12/2007 8:24 AMQuoteAnalyst - 7/12/2007 1:46 PM
A few weeks ago Chris started a thread about the RCS valve problem with "potentially rollback". While this has been true, my thought was "pretty hard words" for a problem not well understood then. A rollback is always *possible*. Doesn't mean there will be one.
Analyst
So you don't want us to report the *facts* about the options open to managers evaluating status? Fact of the matter is, had the valve been the failure point, then yes, rollback would have been the call as the valve could not of been R&Red at the pad. Thankfully, as written, as we followed the process (do we hold back the information until after the event??) the issue was being caused downstream and was corrected.
We're not going to sugarcoat facts, and we sure as hell aren't going to be reporting the style of "can't tell you yet....we'll tell you more after the event". You're on the wrong site if so, as we report live status, as we all follow the process.
We'll be doing that today, from the options of launching tomorrow, delaying, or rollback. Whatever the MMT is evaluating, we'll be reporting it, regardless if it's "harsh words" or not. Facts are facts.
I'm totally with you Chris!! This site is wonderful on reporting all the possibilities firsthand. :)
Post by: Chris Bergin on 12/07/2007 02:18 pm
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psloss - 7/12/2007 11:06 AM
L2 plug: if you review the STS-93 ascent video, you can hear that event called out on one of the booster console's loops.
It's about a 100mb video, but I'll cut some of the end and publish it into this thread.
Post by: Chris Bergin on 12/07/2007 02:28 pm
STS-93 (very eventful). Full video (100mb) on L2. There's another clip at the start here (second post): http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9944&start=1
See below for attachment to download the ECO element of the launch:
Post by: JimO on 12/07/2007 02:33 pm
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mark147 - 7/12/2007 7:01 AM
The cost would be that they would then have an abort condition which would mean a TAL, AOA or ATO, none of which would get Columbus attached to the station and two of which would create delay in getting Atlantis back to KSC (considerably so in the case of a TAL!).
They can trade crew safety against the risk to the programme (due to an abort) but the cost is there in one or the other. Those are no doubt the issues they will be working through today.
Mark
Mark, I seem to recall that landing with undeployed payload was 'possible but not recommended' due to much heavier than nominal touchdown forces, that in the old days would have called for a total orbiter structural inspection and overhaul -- and possibly just writing it off as 'probably damaged and non-verifiable'. An intact orbit might have been the last mission for that particular orbiter, even if the landing was made perfectly.
Post by: Martin FL on 12/07/2007 03:01 pm
Post by: montmein69 on 12/07/2007 03:15 pm
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rfoshaug - 7/12/2007 7:32 AMQuoteGary - 7/12/2007 1:15 PMQuotemontmein69 - 7/12/2007 11:09 AM
Has ESA any say in the matter ? (two astronauts in the crew and Columbus in the bay)
Any say over what? ESA can't force NASA to launch.
I think montmein69 meant if ESA could refuse to launch with their astronauts and their cargo if they are not comfortable with the safety situation.
That was exactly my mind in case the safety rules are modified.
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My opinion is that ESA do not know the details of the inner workings of the shuttle system. NASA and USA do, and when ESA originally decided to lift their cargo and astronauts to orbit on the shuttle, they entrusted that cargo and those astronauts to the engineers and managers of the shuttle program.
Yes, but the deal was made with the "3 of 4" .. and maybe it could be changed to launch in the december window.
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I see no reason why ESA should not trust any decision made by shuttle managers and engineers, whether it is to fly as is or to roll back and fix the problem.
My question was not to discuss about NASA skills but only "Would ESA be consulted or not ?" before the decision is taken to launch as is.
Post by: ras391 on 12/07/2007 03:51 pm
Post by: Orbiter Obvious on 12/07/2007 03:52 pm
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Chris Bergin - 7/12/2007 9:28 AM
Ok, cut it down and reduced the quality to make it fit as an attachment in this thread.
STS-93 (very eventful). Full video (100mb) on L2. There's another clip at the start here (second post): http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=9944&start=1
See below for attachment to download the ECO element of the launch:
Thanks! That's awesome!
Post by: Yegor on 12/07/2007 03:53 pm
Post by: Chris Bergin on 12/07/2007 03:56 pm
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Yegor - 7/12/2007 4:53 PM
When NASA are going to make the decision if they can fly with two faulty sensors?
MMT meet at 2pm Eastern (two hours time). Engineering data is still being collected, though I'm close to getting a new article on site with the latest. I'll have that up as the MMT meets and then update as that proceeds (will be a long MMT).
Also remember, "two faulty sensors" is not exactly the case.
Post by: Yegor on 12/07/2007 04:08 pm
Post by: APAagent on 12/07/2007 04:52 pm
Post by: JimO on 12/07/2007 04:52 pm
are for all permutations of sensor failure modes. My suspicion is that their charts
were pretty mature yesterday, and in the past 24 hrs have fully ripened.
If the MMT isn't convinced, they can give them a few more days and more test resources.
Post by: dember on 12/07/2007 05:19 pm
I have been away for most of the morning.
Post by: William Graham on 12/07/2007 05:20 pm
Post by: dember on 12/07/2007 05:42 pm
Post by: Chris Bergin on 12/07/2007 05:50 pm
Incidently, there's bigger news brewing...so it's going to be a long night folks!
Post by: haywoodfloyd on 12/07/2007 05:58 pm
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Chris Bergin - 7/12/2007 1:50 PM
MMT delayed. There's a huge effort going on with this. Still 50/50 on flying tomorrow.
Incidently, there's bigger news brewing...so it's going to be a long night folks!
Now you've really got us curious, Chris.
Post by: iloco on 12/07/2007 06:08 pm
Now where'd I put my credit card for L2...
Post by: el_nino on 12/07/2007 06:08 pm
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Chris Bergin - 7/12/2007 1:50 PM
MMT delayed. There's a huge effort going on with this. Still 50/50 on flying tomorrow.
Incidently, there's bigger news brewing...so it's going to be a long night folks!
Uh-oh. This doesn't sound good...
Post by: Ford Mustang on 12/07/2007 06:12 pm
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iloco - 7/12/2007 2:08 PM
Do tell Chris! You can't leave us hanging like that!
Now where'd I put my credit card for L2...
I'm sure he'd tell you what he knew.. I'm not sure if he has more information than that... but if he had things he could release, he would have.
This doesn't rule out anything for tomorrow (as of this post), just means they will have a very long day today if they are working towards a launch tomorrow. Feel free to correct me, if something is wrong, but I'm just going off of what I see.
Post by: Chris Bergin on 12/07/2007 06:17 pm
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iloco - 7/12/2007 7:08 PM
Do tell Chris! You can't leave us hanging like that!
Now where'd I put my credit card for L2...
L2's great :) but we'll be running this as a news article, so you'll only need to wait until about 5pm Eastern. I'm unable to say anymore (even on L2, by the way) until then, as I don't have all the info yet. When I do, it's straight to article. It will be 'good' news.
Back to the ECOs....
Post by: joncz on 12/07/2007 06:24 pm
Post by: wannamoonbase on 12/07/2007 06:25 pm
I look forward to the article.
Any hints? Is it STS related?
Edit: I was going to post a guess but I think its better to just wait and not stoke the flames.
Post by: dember on 12/07/2007 07:05 pm
Post by: Chris Bergin on 12/07/2007 07:07 pm
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dember - 7/12/2007 8:05 PM
MMT still delayed?
Was due to start at 3pm (nowish). Waiting for word.
Post by: Johnny Rönnberg on 12/07/2007 07:12 pm
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Chris Bergin - 7/12/2007 7:50 PM
MMT delayed. There's a huge effort going on with this. Still 50/50 on flying tomorrow.
Incidently, there's bigger news brewing...so it's going to be a long night folks!
Some idea when the briefing will take time?
Post by: Chris Bergin on 12/07/2007 07:17 pm
http://www.nasaspaceflight.com/content/?cid=5303
Will be updated as we go through the MMT. Likely to be several hours long.
Post by: Bruce on 12/07/2007 07:24 pm
Definitely not going to be a 5-minute we-all-agree-lets-fly kind of meeting.
Post by: NASA_LaRC_SP on 12/07/2007 07:25 pm
Post by: haywoodfloyd on 12/07/2007 07:37 pm
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Bruce - 7/12/2007 3:24 PM
"ET Project and JSC Engineering are believed to be against any launch attempt on Saturday"
Definitely not going to be a 5-minute we-all-agree-lets-fly kind of meeting.
Don't forget..JSC Engineering was against Endeavor coming back with that "Huge" gouge in her belly. LOL.
Post by: wannamoonbase on 12/07/2007 07:38 pm
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NASA_Langley_spammer - 7/12/2007 3:25 PM
JSC Engineering would dissent their own existance if you asked them.
Both funny and disturbing.
Post by: Andrewwski on 12/07/2007 07:51 pm
Post by: dember on 12/07/2007 07:59 pm
Post by: zentripcity on 12/07/2007 08:01 pm
Post by: dember on 12/07/2007 08:07 pm
Post by: punkboi on 12/07/2007 08:13 pm
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dember - 7/12/2007 1:07 PM If they scrub tomorrow is there a good chance that there will be a rollback?
Depends on what caused the scrub (besides the ECO problem). And Atlantis still has 6 more days to get off the ground (assuming ULA will be flexible with the Atlas V launch).
Post by: zentripcity on 12/07/2007 08:14 pm
Post by: Chris Bergin on 12/07/2007 08:51 pm
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Chris Bergin - 7/12/2007 1:50 PM
Incidently, there's bigger news brewing...so it's going to be a long night folks!
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=11084&posts=1#M220993
Post by: Bruce on 12/07/2007 09:24 pm
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Chris Bergin - 7/12/2007 8:51 PMQuoteChris Bergin - 7/12/2007 1:50 PM
Incidently, there's bigger news brewing...so it's going to be a long night folks!
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=11084&posts=1#M220993
2015! - no need to rush STS-122 then ;)
Post by: James Lowe1 on 12/07/2007 09:31 pm
Post by: Chris Bergin on 12/07/2007 09:46 pm
We're thinking they'll say they need more time for evaluations....
By the way, they've found a crack in a feedline bracket :(
http://www.nasaspaceflight.com/content/?cid=5303
Post by: Skinny on 12/07/2007 09:59 pm
Post by: collectSPACE on 12/07/2007 10:37 pm
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Chris Bergin - 7/12/2007 4:46 PMOfficial word: There is no 8-inch crack. There were "scuff marks", well within limits, noticed during a routine inspection. No other teams are being sent out and the issue never reached the MMT as it was considered too minor for mention.
By the way, they've found a crack in a feedline bracket :(
Post by: Ford Mustang on 12/07/2007 10:48 pm
Post by: GioFX on 12/07/2007 10:49 pm
Post by: ntschke on 12/07/2007 10:57 pm
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zentripcity - 7/12/2007 4:14 PM If they scrub tomorrow, chances are they will rollback for repair
What are you basing that on?
Post by: James Lowe1 on 12/07/2007 10:59 pm
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ntschke - 7/12/2007 5:57 PMQuotezentripcity - 7/12/2007 4:14 PM If they scrub tomorrow, chances are they will rollback for repairWhat are you basing that on?
He's noting his opinion, is how I read it.
Post by: ntschke on 12/07/2007 11:07 pm
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James Lowe1 - 7/12/2007 6:59 PMQuotentschke - 7/12/2007 5:57 PMHe's noting his opinion, is how I read it.Quotezentripcity - 7/12/2007 4:14 PM If they scrub tomorrow, chances are they will rollback for repairWhat are you basing that on?
Thanks James, just wondering if there was some talk about that in the later part of today's meetings and/or some other source of info.
Post by: Ford Mustang on 12/07/2007 11:30 pm
UPDATE: Confirmed via NASA TV slate.
Post by: dember on 12/07/2007 11:33 pm
Post by: mkirk on 12/07/2007 11:33 pm
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Ford Mustang - 7/12/2007 6:30 PM
Seems NET 8:00 PM EST, as they're still running videos? Anyone confirm?
Yes, and actually it will probably be later than that even.
Mark Kirkman
Post by: Avron on 12/07/2007 11:39 pm
Post by: ntschke on 12/07/2007 11:40 pm
Post by: on 12/07/2007 11:41 pm
Post by: strut on 12/07/2007 11:43 pm
I really don't want to go home to the snow and ice, Sunday sounds good to me, Monday everything starts to melt back home
Post by: on 12/07/2007 11:44 pm
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ntschke - 7/12/2007 6:40 PM Based on the fact that they're going to start this press conference late...is there any indication from other sources or via wbecams of any activity that would indicate preps for a launch attempt tomorrow? Such as RSS rollback, lighting or other tell-tale signs?
Still closed around Atlantis.
Post by: Ford Mustang on 12/07/2007 11:48 pm
Post by: bsegal on 12/07/2007 11:48 pm
Post by: bsegal on 12/07/2007 11:49 pm
Post by: Chris Bergin on 12/07/2007 11:50 pm
Post by: Ford Mustang on 12/07/2007 11:51 pm
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Chris Bergin - 7/12/2007 7:50 PM
How are we looking for the time they'll need to retract the RSS? Getting close isn't it?
Last time they retracted it, it was 8:00 PM EST (coming up in 9 minutes)...
EDIT: I'm keeping a look-out on the webcams for RSS Retract... Hoping it'll be soon. :)
Post by: on 12/07/2007 11:53 pm
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Chris Bergin - 7/12/2007 6:50 PM How are we looking for the time they'll need to retract the RSS? Getting close isn't it?
Looks like by now they would need to retract the RSS. With no retract any time soon that can tell us that they aren't going to try for tomorrow.
Post by: Avron on 12/07/2007 11:54 pm
Post by: dember on 12/07/2007 11:55 pm
Post by: shuttlefan on 12/07/2007 11:56 pm
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Justin Wheat - 7/12/2007 6:53 PMQuoteChris Bergin - 7/12/2007 6:50 PM How are we looking for the time they'll need to retract the RSS? Getting close isn't it?Looks like by now they would need to retract the RSS. With no retract any time soon that can tell us that they aren't going to try for tomorrow.
Remember STS-116 a year ago when they didn't retract the RSS until very-late in the count for the second attemt? They've got plenty of time yet. ;)
Post by: Chris Bergin on 12/07/2007 11:56 pm
Speaking of which ET gave strong rationale to carry out a tanking test, pre-MMT.
Post by: on 12/07/2007 11:58 pm
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Chris Bergin - 7/12/2007 6:56 PM Well they'll have some buffer time yet. Trying to work out the very latest for the S0007 requirements, and also if they can do this later if they decide on a tanking test. Speaking of which ET gave strong rationale to carry out a tanking test, pre-MMT.
You thinking they aren't going to try for tomorrow?
Post by: Chris Bergin on 12/07/2007 11:59 pm
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Justin Wheat - 8/12/2007 12:58 AMQuoteChris Bergin - 7/12/2007 6:56 PM Well they'll have some buffer time yet. Trying to work out the very latest for the S0007 requirements, and also if they can do this later if they decide on a tanking test. Speaking of which ET gave strong rationale to carry out a tanking test, pre-MMT.You thinking they aren't going to try for tomorrow?
No, we think they will launch this weekend. Trying to work out if it'll be Sat or Sun.
Post by: Avron on 12/08/2007 12:02 am
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Justin Wheat - 7/12/2007 7:58 PMQuoteChris Bergin - 7/12/2007 6:56 PM Well they'll have some buffer time yet. Trying to work out the very latest for the S0007 requirements, and also if they can do this later if they decide on a tanking test. Speaking of which ET gave strong rationale to carry out a tanking test, pre-MMT.You thinking they aren't going to try for tomorrow?
A try would work as a test... if the ECO's behave then we must be as good to go as any other flight.. they have been a UA for many a year.. so there is nothing new here... other than we see some strange readings, but now know that is conductivity... I would guess that the tanking has done the thermal thing to the connectors and we will be in "steady" state going forward...
Post by: Michael22090 on 12/08/2007 12:03 am
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Chris Bergin - 7/12/2007 6:59 PMQuoteJustin Wheat - 8/12/2007 12:58 AMQuoteChris Bergin - 7/12/2007 6:56 PM Well they'll have some buffer time yet. Trying to work out the very latest for the S0007 requirements, and also if they can do this later if they decide on a tanking test. Speaking of which ET gave strong rationale to carry out a tanking test, pre-MMT.You thinking they aren't going to try for tomorrow?
No, we think they will launch this weekend. Trying to work out if it'll be Sat or Sun.
I would prefer that they went ahead and carried out the tanking test first to be on the safe side. That is, if they think it will be ok to tank another time. I know they don't like to unless absolutely necessary. If they perform a test, how many more chances would they have to tank again later?
Post by: mkirk on 12/08/2007 12:06 am
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Chris Bergin - 7/12/2007 6:59 PMQuoteJustin Wheat - 8/12/2007 12:58 AMQuoteChris Bergin - 7/12/2007 6:56 PM Well they'll have some buffer time yet. Trying to work out the very latest for the S0007 requirements, and also if they can do this later if they decide on a tanking test. Speaking of which ET gave strong rationale to carry out a tanking test, pre-MMT.You thinking they aren't going to try for tomorrow?
No, we think they will launch this weekend. Trying to work out if it'll be Sat or Sun.
Flight Control Team in Houston is being told NET Sunday!
Mark Kirkman
Post by: Chris Bergin on 12/08/2007 12:08 am
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mkirk - 8/12/2007 1:06 AMQuoteChris Bergin - 7/12/2007 6:59 PMQuoteJustin Wheat - 8/12/2007 12:58 AMQuoteChris Bergin - 7/12/2007 6:56 PM Well they'll have some buffer time yet. Trying to work out the very latest for the S0007 requirements, and also if they can do this later if they decide on a tanking test. Speaking of which ET gave strong rationale to carry out a tanking test, pre-MMT.You thinking they aren't going to try for tomorrow?
No, we think they will launch this weekend. Trying to work out if it'll be Sat or Sun.
Flight Control Team in Houston is being told NET Sunday!
Mark Kirkman
Copy that Mark!
Post by: on 12/08/2007 12:13 am
Post by: psloss on 12/08/2007 12:13 am
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shuttlefan - 7/12/2007 7:56 PMYes, and that was working a 48-hour scrub turnaround, too.
Remember STS-116 a year ago when they didn't retract the RSS until very-late in the count for the second attemt? They've got plenty of time yet. ;)
Post by: psloss on 12/08/2007 12:17 am
Post by: mike robel on 12/08/2007 12:19 am
Post by: collectSPACE on 12/08/2007 12:21 am
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mike robel - 7/12/2007 7:19 PMThey announced Sunday at 3:21 p.m. EST at the KSC press site.
Florida Today just reported via text message scrubbed NeTl Sunday around 1500
MMT is still meeting. Wayne Hale and Mike Leinbach are expected to come over to briefing.
Post by: Michael22090 on 12/08/2007 12:33 am
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Gary - 7/12/2007 7:19 PMQuotepsloss - 8/12/2007 1:17 AM
Now bumped to NET 8:45 pm Eastern...
And to paraphrase an earlier reply - I'll see your 8:45pm and raise you a 9pm :laugh:
LOL! I think I can quote this STS-122 Mission Overview by heart now. This is like the 20th time I have seen it now. :laugh:
Post by: Seattle Dave on 12/08/2007 12:34 am
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Bubbinski - 7/12/2007 7:30 PM
Seattle Dave, are you saying Saturday is still on the table?
No, I was saying that scrubbed Sunday is wrong, they are looking at Sunday. And the launch time is wrong anyway. See Robert's post for the correct launch time.
Post by: Chris Bergin on 12/08/2007 12:37 am
Post by: shuttlefan on 12/08/2007 12:40 am
Post by: Andrewwski on 12/08/2007 12:44 am
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Chris Bergin - 7/12/2007 8:37 PM
NET 9pm.
Do I hear 9:15? 9:30? Sold to the bidder on the left for midnight!
Post by: Chris Bergin on 12/08/2007 12:46 am
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shuttlefan - 8/12/2007 1:40 AM
Chris mentioned earlier that the ET project was leaning towards a tanking test going into the MMT meeting. Would a tanking test tomorrow, then a launch count Sunday be an option?
ET gave good rationale for the tanking test, but it doesn't mean MMT would take up that option.
We have a lot more presentations via L2, and tomorrow I'll do an article based on Flight Controller proccedures with regards to the ECOs and other items to round it up.
Post by: collectSPACE on 12/08/2007 12:46 am
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Andrewwski - 7/12/2007 7:44 PMIt was announced here at the press site as a solid 9pm.
Do I hear 9:15? 9:30? Sold to the bidder on the left for midnight!
Post by: triddirt on 12/08/2007 12:47 am
Dec. 7 - 8:30 p.m. EST
Due to the length of tonight's Mission Management Team discussion, we are no go for a Saturday launch. The next attempt would be no earlier than Sunday at 3:21:00 p.m. EST.
A news conference is coming up on NASA TV no earlier than 9 p.m.
For a launch attempt on Sunday, tanking coverage on NASA TV would begin at 6 a.m., with launch coverage starting at 10 a.m.
Post by: psloss on 12/08/2007 12:49 am
Post by: punkboi on 12/08/2007 12:49 am
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Seattle Dave - 7/12/2007 5:34 PMQuoteBubbinski - 7/12/2007 7:30 PM Seattle Dave, are you saying Saturday is still on the table?No, I was saying that scrubbed Sunday is wrong, they are looking at Sunday. And the launch time is wrong anyway. See Robert's post for the correct launch time.
The launch target for Sunday is 3:21 PM, EST
Post by: Ford Mustang on 12/08/2007 12:53 am
Post by: Chris Bergin on 12/08/2007 12:59 am
http://www.msnbc.msn.com/id/22151584/
Post by: collectSPACE on 12/08/2007 01:01 am
Post by: psloss on 12/08/2007 01:03 am
Post by: Ford Mustang on 12/08/2007 01:04 am
Post by: psloss on 12/08/2007 01:05 am
Post by: Ford Mustang on 12/08/2007 01:09 am
Post by: psloss on 12/08/2007 01:12 am
Post by: Ford Mustang on 12/08/2007 01:12 am
Post by: Chris Bergin on 12/08/2007 01:12 am
Post by: psloss on 12/08/2007 01:13 am
Post by: triddirt on 12/08/2007 01:14 am
Post by: psloss on 12/08/2007 01:14 am
Post by: psloss on 12/08/2007 01:15 am
Post by: Falcon on 12/08/2007 01:16 am
Post by: psloss on 12/08/2007 01:17 am
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Falcon - 7/12/2007 9:16 PMYes, that was part of the proposal that Wayne Hale mentioned came from the Flight Crew Office (FCOD).
Mike Leinbach just said the new flight rules require all 4 of the ECO sensors to be working. So if they try to launch Sunday and there are any problems with the ECO sensors, it'll be a scrub.
Post by: Ford Mustang on 12/08/2007 01:20 am
Hale says "Going to 2 of 4 is not where we want to be.."
Post by: psloss on 12/08/2007 01:21 am
Post by: psloss on 12/08/2007 01:28 am
Post by: psloss on 12/08/2007 01:32 am
Post by: psloss on 12/08/2007 01:33 am
Post by: ArielGold on 12/08/2007 01:35 am
Post by: psloss on 12/08/2007 01:41 am
Basically, if the proposal is accepted and any of the LH2 ECO circuits fail (WET or DRY) during the next tanking, they would be no-go.
Post by: psloss on 12/08/2007 01:45 am
Post by: Ford Mustang on 12/08/2007 01:46 am
Tanking will start at 5:55 AM EST on Sunday, if they do decide to go with a Sunday launch.
Intermittent updates on tanking will be before launch coverage, barring they go with Sunday.
Post by: dember on 12/08/2007 01:47 am
Post by: nsf-rt on 12/08/2007 01:54 am
Another question arising from the briefing is where does the output of the new "voltmeter" readings coming out of these sensors get routed to - do the crew have access to these live during ascent, are they fed into the computers, or are they read by people on the ground?
Post by: ETEE on 12/08/2007 01:54 am
On the sensor system, it seems strange to me that an open circuit wiring fault on the ECO sensors is designed as a fail to wet. Surely it would be better and safer if an o/c fault failed to dry?
Post by: TJL on 12/08/2007 01:55 am
Post by: Chris Bergin on 12/08/2007 01:58 am
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TJL - 8/12/2007 2:55 AM
What time is T-0 on Sunday attempt?
3:21pm in a one minute launch window (mentioned earlier ;) but it's a long ass thread now).
Thinking of starting a new one half way through tomorrow when the next article on MMT documentation is up.
Post by: psloss on 12/08/2007 02:04 am
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nsf-rt - 7/12/2007 9:54 PMYes, that's how I interpret 4/4 -- because any failure of any of the circuits (the likelihood would be failing WET) wouldn't fit the behavior seen in the past. Granted the second STS-114 tanking (on the second ET) occurred after they went into the aft and did a lot of work, but in both the STS-114 and STS-115 cases on the second tanking all the sensor circuits behaved as expected.
Someone at the briefing did ask about when during the count down 4/4 sensors had to be working. I didn't think the answer was clear. Is it the case that if one sensor behaves unexpectedly at any point that day's tanking and subsequent launch attempt will be scrubbed, or are they looking just for 4/4 to be working at the point they commit to launch? (As I write this I can see psloss has interpreted the briefing as any sensor failure during tanking will result in a scrub. )
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nsf-rt - 7/12/2007 9:54 PMTelemetry that can be seen in the control centers (LCC and MCC) and not directly by the crew on the flight deck. I don't believe the orbiter flight software uses the voltage parameters in its logic.
Another question arising from the briefing is where does the output of the new "voltmeter" readings coming out of these sensors get routed to - do the crew have access to these live during ascent, are they fed into the computers, or are they read by people on the ground?
Post by: SiameseCat on 12/08/2007 02:05 am
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ETEE - 7/12/2007 9:54 PM
This is a very good plan and I have every confidence in Mr Hale. On the sensor system design, it seems strange to me that an open circuit wiring fault on the ECO sensors is being interpreted as a fail to wet. Surely a design with o/c fault failing to dry would be better and safer?
No, because an ECO sensor reading dry implies an already off-nominal condition. With the current setup, a completely empty tank will result only if three ECO sensors fail and fuel is used at an abnormally high rate. If the ECO sensors failed dry, a failure of only two sensors would result in premature engine cutoff.
Post by: punkboi on 12/08/2007 02:09 am
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nsf-rt - 7/12/2007 6:54 PM Someone at the briefing did ask about when during the count down 4/4 sensors had to be working. I didn't think the answer was clear. Is it the case that if one sensor behaves unexpectedly at any point that day's tanking and subsequent launch attempt will be scrubbed, or are they looking just for 4/4 to be working at the point they commit to launch? (As I write this I can see psloss has interpreted the briefing as any sensor failure during tanking will result in a scrub. )
The sensors have to be 4/4 during tanking. Otherwise, NASA would have proceeded with the launch attempt yesterday in the hopes the 2 ECO sensors suddenly started to work nominally by T-0. :bleh:
Post by: scott6428 on 12/08/2007 02:15 am
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psloss - 7/12/2007 9:13 PM
Mike Leinbach notes that the LH2 top off completed a few hours ago; can support Sunday and Monday attempts. After that 72-hour recycle to top both cyro quantities.
I'm wondering if that's absolute. If they scrub early say due to weather on Monday would they have sufficient cyro to consider Tuesday? or start top off early for a Wednesday attempt?
Scott.
Post by: rdale on 12/08/2007 02:20 am
Post by: George CA on 12/08/2007 03:50 am
Post by: Joffan on 12/08/2007 04:19 am
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SiameseCat - 7/12/2007 8:05 PMQuoteETEE - 7/12/2007 9:54 PM
This is a very good plan and I have every confidence in Mr Hale. On the sensor system design, it seems strange to me that an open circuit wiring fault on the ECO sensors is being interpreted as a fail to wet. Surely a design with o/c fault failing to dry would be better and safer?
No, because an ECO sensor reading dry implies an already off-nominal condition. With the current setup, a completely empty tank will result only if three ECO sensors fail and fuel is used at an abnormally high rate. If the ECO sensors failed dry, a failure of only two sensors would result in premature engine cutoff.
and the track record to-date - 2 uses of ECO sensors out of 120 launches - tells us with 99% confidence that the chance of even needing the ECO sensors is less than 7% (binomial stats), so risking the mission on a faulty sensor going DRY would be a serious unnecessary loss-of-mission risk.
Post by: Zachstar on 12/08/2007 05:05 am
Please don't fire back with the "You want to put the crew at risk?" junk I think the crew will be in a much more serious position if they suddenly found themselves the first to attempt the most realistic version of the TAL abort. Even if they do manage to get over the panic and shock of suddenly finding yourself in such a situation and making it to a smooth landing. Do you think any of them will be fit for flying again? (Mentally) Do you think there even will be shuttle flights afterwards?
Call me an idiot if you wish but I think the chances of them losing their lives to an ECO sensor failure (DRY) is much higher than somehow getting in a position where the engine destroys the shuttle due to the tank running dry (Think about what has to happen for that to happen). The chances of a piece of metal or worse blocking the fuel transport and causing a failure has to be much higher
EDIT: Forgot that it takes engine power to do a RTLS.
Post by: ChrisGebhardt on 12/08/2007 05:17 am
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Joffan - 8/12/2007 12:19 AMQuoteSiameseCat - 7/12/2007 8:05 PMQuoteETEE - 7/12/2007 9:54 PM
This is a very good plan and I have every confidence in Mr Hale. On the sensor system design, it seems strange to me that an open circuit wiring fault on the ECO sensors is being interpreted as a fail to wet. Surely a design with o/c fault failing to dry would be better and safer?
No, because an ECO sensor reading dry implies an already off-nominal condition. With the current setup, a completely empty tank will result only if three ECO sensors fail and fuel is used at an abnormally high rate. If the ECO sensors failed dry, a failure of only two sensors would result in premature engine cutoff.
and the track record to-date - 2 uses of ECO sensors out of 120 launches - tells us with 99% confidence that the chance of even needing the ECO sensors is less than 7% (binomial stats), so risking the mission on a faulty sensor going DRY would be a serious unnecessary loss-of-mission risk.
I'm aware of the Columbia low-level cutoff on STS-93... what was the other occurrence of the use of the ECO sensors?
Post by: sdsds on 12/08/2007 05:31 am
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psloss - 7/12/2007 6:21 PM
The logic behind going back to 4 of 4 is the tanking history (no failed WET channels during retanking).
This logic is not compelling. We have no clue about the root cause. Sure, we've launched while clueless like this several times before and we didn't lose the crew, vehicle or mission those times. Does that mean if we launch clueless again, we can expect the same result?
How many tanks have been launched with sensors that had incorrectly indicated "wet" on tests during prior tankings, and then 4 of 4 correctly responded "dry" on the test for the final tanking? Would a Bayesian analysis give us very high confidence in the outcome of the next such launch?
We shouldn't even be in this situation, because we shouldn't have attempted those prior launches when there had been unexplained behavior from a life-critical system. That was "go fever" thinking then, and it is "go fever" thinking to launch with this tank now. STS should not launch again until a root cause for the sensor failures has been determined.
Post by: ChrisGebhardt on 12/08/2007 05:40 am
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sdsds - 8/12/2007 1:31 AMQuotepsloss - 7/12/2007 6:21 PM
The logic behind going back to 4 of 4 is the tanking history (no failed WET channels during retanking).
This logic is not compelling. We have no clue about the root cause. Sure, we've launched while clueless like this several times before and we didn't lose the crew, vehicle or mission those times. Does that mean if we launch clueless again, we can expect the same result?
How many tanks have been launched with sensors that had incorrectly indicated "wet" on tests during prior tankings, and then 4 of 4 correctly responded "dry" on the test for the final tanking? Would a Bayesian analysis give us very high confidence in the outcome of the next such launch?
We shouldn't even be in this situation, because we shouldn't have attempted those prior launches when there had been unexplained behavior from a life-critical system. That was "go fever" thinking then, and it is "go fever" thinking to launch with this tank now. STS should not launch again until a root cause for the sensor failures has been determined.
If you'd have listened to the briefings you would know that this is an intermitant problem with the ECO sensors or their related wiring. You can't diagnose a problem (let a lone find root cause) if the problem goes away the next time you tank for troubleshooting.
And saying that we shouldn't have launched those previous attempts means STS-114 would still be on the ground and we'd still be waiting to Return to Flight from Columbia. That's not very logical! You have to take it for what it is. There is always risk in space flight and having one ECO sensor fail still leaves plenty of redundancy in the system. Granted this situation is different, but for all we know we could tank and de-tank this ET a hundred times and never recreate what we saw on Thursday. How would that help us find root cause?
Also, keep in mind that this management team has done a tremendous job preventing launch fever. If this were launch fever Atlantis would have launched on Friday, the day after the three ECO sensors first gave them trouble.
Also, keep in mind that Sunday is a No Earlier Than date... it doesn't mean they're defeinetely going to try to launch tomorrow it just means they've told the launch team to be ready to try on Sunday. They could just as easily come back tomorrow and say "we're not going to try until Monday or even January.
Post by: Zachstar on 12/08/2007 05:40 am
Post by: sdsds on 12/08/2007 07:32 am
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Zachstar - 7/12/2007 10:40 PMA tank could run dry for a variety of reasons, and without ECO sensors reporting that condition it would likely result in a catastrophic engine failure leading to loss of the crew.
Sdsds What? The ECO system is wrong, broken, gone to hell, or whatever you want to call it. You want them to actually spend potentially years finding the "root cause" on a system which should be disabled?
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Zachstar - 7/12/2007 10:40 PMThe crews train to perform TAL aborts, and there is every reason to have confidence in their ability to do so. But there is no way to save a vehicle if an engine explodes.
What if the supposed fix causes the sensors to fail DRY during launch and the crew crashes the shuttle attempting a TAL Abort?
I would like to see NASA return humans to the Moon in my lifetime, and if we lose another Shuttle crew that just won't happen.
Post by: Tschachim on 12/08/2007 08:52 am
Thanks
Tschachim
Post by: Justin Space on 12/08/2007 09:37 am
Post by: Mark Dave on 12/08/2007 11:06 am
Post by: psloss on 12/08/2007 11:12 am
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sdsds - 8/12/2007 1:31 AMAre your questions above rhetorical? If not, then it's hard to agree with your conclusion because you have presented very little rationale for it. The way I read it, you're asserting that they shouldn't launch until they completely understand how the system works. If that's the rule, then it's a Catch-22.
How many tanks have been launched with sensors that had incorrectly indicated "wet" on tests during prior tankings, and then 4 of 4 correctly responded "dry" on the test for the final tanking? Would a Bayesian analysis give us very high confidence in the outcome of the next such launch?
We shouldn't even be in this situation, because we shouldn't have attempted those prior launches when there had been unexplained behavior from a life-critical system. That was "go fever" thinking then, and it is "go fever" thinking to launch with this tank now. STS should not launch again until a root cause for the sensor failures has been determined.
Post by: psloss on 12/08/2007 11:15 am
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Trekkie07 - 8/12/2007 1:17 AM51-F. In both cases the LOX low-level sensors went dry first, as designed.
I'm aware of the Columbia low-level cutoff on STS-93... what was the other occurrence of the use of the ECO sensors?
Post by: ntschke on 12/08/2007 11:18 am
Post by: psloss on 12/08/2007 11:31 am
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ntschke - 8/12/2007 7:18 AMNASA.gov reposted schematics:
Maybe this is available here on another site but I haven't found it yet...does anyone know if there is an ET reference guide, schematic, cut-away view etc that might be of use in visualizing the different components invovled in this debate?
http://www.nasa.gov/mission_pages/shuttle/main/
Or do you mean something else?
(And actually, the overall schematic is in Mark's Interspacenews story that has been linked in this thread already.)
Post by: Bejowawo on 12/08/2007 11:41 am
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psloss - 8/12/2007 1:15 PMQuoteTrekkie07 - 8/12/2007 1:17 AM51-F. In both cases the LOX low-level sensors went dry first, as designed.
I'm aware of the Columbia low-level cutoff on STS-93... what was the other occurrence of the use of the ECO sensors?
If I read it correctly, this time the LH2 sensors failed, right? Are those same sensors used in the LOX tank or do they have a different design. (I am wondering why only those sensors in the LH2 tank show this erroneous readings.)
Couldn't it be that the material of the sensors has changed over time to an extent, that it is susceptible to a "chemical" LH2 attack in some way. As I work steel industry, I experienced quite a few cases where H2 is altering material to a point where it's beyond it's designed behaviour and has to be replaced.
Post by: ntschke on 12/08/2007 11:41 am
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psloss - 8/12/2007 7:31 AMQuotentschke - 8/12/2007 7:18 AM Maybe this is available here on another site but I haven't found it yet...does anyone know if there is an ET reference guide, schematic, cut-away view etc that might be of use in visualizing the different components invovled in this debate?NASA.gov reposted schematics: http://www.nasa.gov/mission_pages/shuttle/main/ Or do you mean something else? (And actually, the overall schematic is in Mark's Interspacenews story that has been linked in this thread already.)
Thanks,I saw those from an erlier post and they help but I thought in the past, somehwere, I saw a nice detailed cut away view of the ET and exploded views of the seperate tanks, pipes, etc. Just tying to get an idea of access and internal workings of the bottom of the tank.
And just to get my "Mulligan" dumb question of the day out of the way early...I'm assuming that the shear velocity of the vehicle throughout ascent (and at the point that ECOs would even be needed) keeps the fuel forced to the bottom of the tank? I assume at those speeds the tank almost always "feels" like its in a vertical position?
Post by: joncz on 12/08/2007 11:47 am
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ntschke - 8/12/2007 7:41 AM
And just to get my "Mulligan" dumb question of the day out of the way early...I'm assuming that the shear velocity of the vehicle throughout ascent (and at the point that ECOs would even be needed) keeps the fuel forced to the bottom of the tank? I assume at those speeds the tank almost always "feels" like its in a vertical position?
It's not the velocity, it's the acceleration, but yes, that's what keeps the fuel filling the bottom dome.
Post by: ShuttleFan75 on 12/08/2007 11:47 am
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ntschke - 8/12/2007 12:41 PM
Thanks,I saw those from an erlier post and they help but I thought in the past, somehwere, I saw a nice detailed cut away view of the ET and exploded views of the seperate tanks, pipes, etc. Just tying to get an idea of access and internal workings of the bottom of the tank.
L2, STS-122: ECO SYSTEM INFO/BACKGROUND on the STS-122 Special Section has the Booster Console handbook area for ECO and lots of very cool schematics and images of the sensors that are obviously not on NASA.gov
I've bumped it for you, as I know you're on L2.
Post by: psloss on 12/08/2007 11:53 am
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ntschke - 8/12/2007 7:41 AMShortly before liftoff both tanks are pressurized and then the MPS maintains a "top" pressure (ullage pressure) within them; this isn't the best link, but it was quick:
And just to get my "Mulligan" dumb question of the day out of the way early...I'm assuming that the shear velocity of the vehicle throughout ascent (and at the point that ECOs would even be needed) keeps the fuel forced to the bottom of the tank? I assume at those speeds the tank almost always "feels" like its in a vertical position?
http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/prop/et.html
The program folks here can explain better.
Post by: ntschke on 12/08/2007 11:54 am
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ShuttleFan75 - 8/12/2007 7:47 AMQuotentschke - 8/12/2007 12:41 PM Thanks,I saw those from an erlier post and they help but I thought in the past, somehwere, I saw a nice detailed cut away view of the ET and exploded views of the seperate tanks, pipes, etc. Just tying to get an idea of access and internal workings of the bottom of the tank.L2, STS-122: ECO SYSTEM INFO/BACKGROUND on the STS-122 Special Section has the Booster Console handbook area for ECO and lots of very cool schematics and images of the sensors that are obviously not on NASA.gov I've bumped it for you, as I know you're on L2.
Thanks to all of you. Also, I found this on wiki (http://en.wikipedia.org/wiki/Space_Shuttle_external_tank):
"There are eight propellant-depletion sensors, four each for fuel and oxidizer. The fuel-depletion sensors are located in the bottom of the fuel tank. The oxidizer sensors are mounted in the orbiter liquid oxygen feed line manifold downstream of the feed line disconnect. During SSME thrusting, the orbiter general-purpose computers constantly compute the instantaneous mass of the vehicle due to the usage of the propellants. Normally, main engine cutoff is based on a predetermined velocity; however, if any two of the fuel or oxidizer sensors sense a dry condition, the engines will be shut down.
The locations of the liquid oxygen sensors allow the maximum amount of oxidizer to be consumed in the engines, while allowing sufficient time to shut down the engines before the oxidizer pumps cavitate (run dry). In addition, 1,100 pounds (500 kg) of liquid hydrogen are loaded over and above that required by the 6-1 oxidizer / fuel engine mixture ratio. This assures that cutoff from the depletion sensors is fuel-rich; oxidizer-rich engine shutdowns can cause burning and severe erosion of engine components.
Four pressure transducers located at the top of the liquid oxygen and liquid hydrogen tanks monitor the ullage pressures"
Post by: psloss on 12/08/2007 12:00 pm
Here's a post that Mark made a while back -- scroll down to the part on NPSP:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=7886&start=1#M139197
Post by: Jim on 12/08/2007 12:14 pm
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ntschke - 8/12/2007 7:54 AM
Also, I found this on wiki
please don't use wiki for space
Post by: Martin FL on 12/08/2007 02:11 pm
Post by: Life_Support_32 on 12/08/2007 02:17 pm
Post by: psloss on 12/08/2007 02:33 pm
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Life_Support_32 - 8/12/2007 10:17 AMRemember that the vehicle acceleration is 3g for the last several seconds of a nominal ascent. Cutting off at "arm" would cause a still substantial underspeed and may be beyond the delta-V capability of the OMS and RCS.
Maybe I interpreted this wrong, but didn't they say at the press conference last night that the onboard computer system won't even use the ECO sensors unless they are within 10 seconds of nominal MECO anyways? At that point, the velocity and altitude would leave only an ATO with the OMS engines, not the RTLS or TAL that other people are talking about.
Post by: psloss on 12/08/2007 02:35 pm
Post by: Chris Bergin on 12/08/2007 02:39 pm
Post by: Real Madrid on 12/08/2007 03:53 pm
http://www.cbsnews.com/network/news/space/122/122windows.html
Post by: dember on 12/08/2007 03:56 pm
Post by: James Lowe1 on 12/08/2007 03:57 pm
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dember - 8/12/2007 10:56 AM
Is this news conference scheduled for 1:00?
No, as stated in the article on the front of the site (do read it), the MMT starts at 1pm.
Post by: dember on 12/08/2007 03:59 pm
Post by: trlstyle on 12/08/2007 04:05 pm
Post by: James Lowe1 on 12/08/2007 04:14 pm
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trlstyle - 8/12/2007 11:05 AM
MMT meets at 1 - so any what time should we hear if Sunday is a go or not?
Probably a few hours later at least.
Post by: Chris Bergin on 12/08/2007 06:22 pm
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=11092&posts=1&start=1