STS-122 (1E) Updates

[Zipi]

Maybe a dumb question, but I cannot help myself... Why the wires cannot simply be soldered to the pins of the connector? A quick and dirty fix... Then add some hot glue or similar more high tech stuff to keep the water out... <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

It's not a dumb questiuon at all!!<br /><br />Well, one reason is that IIRC, there are over 30 pins in this connector, in a very tight area...maybe an inch across? How do you solder in there?<br /><br />Second, how would a soldered joint react at -200 degrees? I don't know, you don't know, and they don't know.<br /><br />You can't just slap in a fix without some testing. If a wire came loose during launch and flopped around, I'd suspect bad things could happen.<br /><br />My tweaking the pin idea wouldn't substantially change things, so I think is a better idea. <br /><br />They also have the option of flying as is with a much better understanding of what is going on. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

Just a reminder the post tanking test news conference will be on NASA TV NET (No Earlier Than) 4:30 PM EDT, (1:30 PM PST, 2130 UT {or GMT} )<br /><br />Wayne Hale will be there, so it should be professional, educational, and a bit entertaining.<br /><br />I love this guy.<br /><br />Another Wayne <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[Zipi]

I'm pretty sure that the soldered joint will be fine with -200 degrees. But when you add that vibration what the boosters are making then I'm not sure at all. :-<br /><br />Without any physical stress the soldered joint is probably ok, think for example those computer overclocking enthusiasts who are putting regular consumer electronics to those temps. Of course it depends on the connecor and wire materials as well... But still I believe it would work.<br /><br />What comes to those multiple pins in the "tiny" connector... I didn't know that. But I guess Nasa have electronic guys who are able to do such precision work. <div class="Discussion_UserSignature"> </div>

 

[Zipi]

"The wire to pin connection is not the problem. "<br /><br />No, but if I understood correctly the pin to pin connection is. If you don't use the second connector at all, but "rape" the connector at the tank and solder the wires directly to the pins of it. <div class="Discussion_UserSignature"> </div>

 

[vulture2]

What puzzles me is why the fill sensors (at the top of the LH2 tank) don't seem to have this problem. Are they a different design, or do they use a different interface? The LOX ECO sensors also seem to have been fairly reliable, but as I understand it they are in the Orbiter.

 

[Testing]

SG, can the connector be demated at the pad? If so could it be packed with something like DC-4 and remated to exclude Liquid Air/ moisture? <div class="Discussion_UserSignature"> </div>

 

[Zipi]

"What puzzles me is why the fill sensors (at the top of the LH2 tank) don't seem to have this problem. Are they a different design, or do they use a different interface? The LOX ECO sensors also seem to have been fairly reliable, but as I understand it they are in the Orbiter. "<br /><br />Cold air tends to move down, if I have red my physics correctly... Assuming they are using separate connectors and the distance of the connectors is somehow significant. <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Well there's no air there, it's all liquid LH2.<br /><br />Probably the difference is the time they are exposed to cryogenic temperatures (the top if the tank is filled for less time than the bottom) and possibly this:<br /><br />Since the problem seems to be ice forming in the connector, by the time the top of the tank is cooled, the moisture in the area has been consumed in forming ice lower on the tank.<br /><br />Of course, the connector at the top could be a different design, and if I was planning it, would probably be as high up as possible, in the gaseous Hydrogen area.<br /><br />I do not know any of the details, so this is pure speculation. Just thinking out loud. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[mcs_seattle]

Shuttle Guy - <br /><br />Have you ever had an area that you are responsible for be the cause of a launch hold up/cancellation? If so, what is that like?

 

[MeteorWayne]

Looks like the tanking test briefing might occur close to the planned time....about now. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bobw]

The good news is that they found the spot with the ratty connector. The bad news is they may have to go into the tank or design new parts to fix it. <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Quick synopsis of todays test.<br /><br />3 sensors failed for various lengths of time.<br /><br />All the trouble occurred at the pass through connector (between the inside and outside of the LH2 tank), so the source point of the problem is known.<br />The type of failure(open circuit) is also verified.<br /><br />That is the superb result of this test.<br /><br />What the fix might be has not been determined yet.<br /><br />I learned there is actually a 5th sensor, that gives a 5% indication before the problematic sensors would be dry.<br /><br />More later.<br /><br />MW <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bobblebob]

So would the open circuit indicate just human error when building this spectific ET and connecting everything together, or is there a more fundemental problem that could effect future ET's?

 

[bobblebob]

Ive just got in aswell, have i missed the conference? Nasa site still says NET 4:30 ET

 

[MeteorWayne]

It's unlikely to be a build error, though it is possible.<br /><br />Wayne even suggested maybe an engineering change made a decade ago could have caused it.<br /><br />It could be small little nanobots form Alpha Ceti are screwing it up.<br /><br />At this point, they just don't know what the cause is.<br /><br />They DO know where to look to fix the problem.<br /><br />Let's not overanalyze a problem that has just been confirmed as existing. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

That was 45 minutes ago from when you posted.<br /><br />It's an hour and twenty minutes ago when I'm posting <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[bobblebob]

Sorry meant to say did the conference happen on time at 4:30 ET as i wasnt online at the time? From pervious experience with Nasa conferences we all know they like to delay them <img src="/images/icons/wink.gif" />

 

[moonmadness]

LIES!! More Beta Proxima propaganda against the peaceful citizens of Alpha Ceti.<br /><br /><br /><img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p>I'm not a rocket scientist, but I do play one on the TV in my mind.</p> </div>

 

[moonmadness]

Will they replace the external connector then do a fill test and hope that works? <div class="Discussion_UserSignature"> <p>I'm not a rocket scientist, but I do play one on the TV in my mind.</p> </div>

 

[rainergerhards]

I have written a log from yesterday's NASA TV coverage of the tanking test (as far as it was possible, they cut off the stream during detanking). Maybe it is of interest for some of you:<br /><br />http://spacelaunch.gerhards.net/2007/12/space-shuttle-atlantis-tanking-test-in.html<br /><br />From what I have seen during the test and heard before it, there was flight rationale based on the fact that engineers expected the ECO sensor system not to change status after an inital OK or failure. The test, I think, has shown this is not true. Does anybody know if/how that affects flight rationale? <br /><br />Rainer

 

[bobblebob]

Thanks alot for that detailed report of events yesterday. Read it at work, passed abit of time and very interested as i couldnt watch it live yesterday <img src="/images/icons/smile.gif" />

 

[vulture2]

Rollback looks more likely. They have delayed preps for the next mission. The problem could be eliminated with a minor design change, but it takes so long to make any change to a man-rated vehicle that one wonders if it will be done. However they had the money to develop a heads-up display for the Back-up Flight System that was just announced. How likely is that to be used?

 

[bobblebob]

Will the engineers be working over Christmas then to get this analysed, tested and fixed in the hope of meeting the Jan window? <br /><br />They deserve some time off this year, been a hard year for them

 

[erioladastra]

"yes "<br /><br />Well it will be interesting... it appears that from an operations point of view we cannot support the BGA repair EVA and 1E at its current launch. Operations is so burned out that management has pretty much said absolutely no one is working the holidays. (not counting all of us working 26P, 27P...)