Drudge: foam cracks on ET

[j05h]

10AM Monday, drudgreport.com: "Crack found in foam of space shuttle’s external fuel tank... Developing... "<br /><br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

( my slashdot post: )<br /><br />As of Monday AM. NPR says it's a 5 inch crack. I'm not sure if this is a big issue or grandstanding, but it could scrap this launch. Thermal cycling of the tank causes the cracks, they've tanked Discovery twice so this is to be expected. It definitely poses an added element of risk. If they are going to fly, they need to light that candle. Otherwise, stop the song-and-dance routine. <br /><br />I want to see them succeed, finish the ISS and retire the Shuttles with dignity. What I don't want is for Shuttle to limp along with 1 or 2 flights a year and keep sucking NASA dry. We have a one-time opportunity to begin working on Mars flights, don't blow it. <br /><br />Added: link to spaceflightnow.com article<br /><br />http://www.spaceflightnow.com/shuttle/sts121/060703crack/<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[spacefire]

all I can say is 'hilarious'! <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[CalliArcale]

I wouldn't jump to conclusions (at least, I wouldn't if I were an engineer on the team) as to the cause of the crack; there is the possibility it was there before they first tanked and nobody noticed. That's the trouble with this sort of thing; when you first spot it, you have no way of knowing how long it's been there.<br /><br />I must admit, though, that ET cycling was my first thought too.<br /><br />There's a piece of foam on the MLP; last I heard, they didn't know where it came from. It may be related to the crack, or it may not. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[j05h]

I'm just aggregating info, with some commentary. This is either normal or no-go, I just want NASA to get on with it. <br /><br />The foam on the platform would indicate the ET crack is recent, IMHO. <br /><br /> /> spacefire:<i> all I can say is 'hilarious'! </i><br /><br />It is in no way funny. Lives, treasure and reputations are at risk. We as Americans must support human spaceflight or be on the dustbin of history. I'm not a Shuttle fan, but show some respect. <br /><br />from: http://blogs.orlandosentinel.com/news_space_thewritestuff/2006/07/foam_falls_from.html<br /><br />" The inboard strut for the L02 Feedline Bracket assembly at XT-1129 was found to be cracked. The damage is approx 5-6 inches long and appears to originate near the where the strut connects to the feedline and extends toward the ET. The TPS crack is approx ¼ inch wide with an offset of approx ¼ inch. An IPR was initiated for this item. Inboard views of the remaining visible brackets did not reveal any similar damage. Outboard views of the feedline brackets revealed areas of TPS debris in the gap between the feedline and the bracket – this condition was noticed at XT-1129, 1377, and 1623. No obvious indications of crushed foam or debris was detected at the XT-1871 and 1978 brackets. "<br /><br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[no_way]

If you follow the "Flame Trench" blog you can see that the foam chunks are actually falling already. a big enough chunk to damage the orbiter fell off. http://www.floridatoday.com/floridatoday/blogs/spaceteam/

 

[grooble]

I thought the foam problem would be fixed by now, and if it can't be fixed, either fly anyway or cancel the program.<br /><br />

 

[j05h]

That chunk of foam is 3 inches wide! The blog suggested it was knocked off by the service platform - what is going on?<br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[radarredux]

> <i><font color="yellow">If you follow the "Flame Trench" blog you can see that the foam chunks are actually falling already. a big enough chunk to damage the orbiter fell off.</font>/i><br /><br />Sigh...<br /><br />Griffin was already launching under criticism because of the chief engineer and safety officer gave the launch a "no go". With foam already falling off, this is going to make it really difficult politically to launch.</i>

 

[j05h]

*Groan* The oxygen line with the crack is right in front of Discovery's nose. Still no word on where exactly the 3inch chunk fell from.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[erioladastra]

"I thought the foam problem would be fixed by now, and if it can't be fixed, either fly anyway or cancel the program. "<br /><br />No, Griffin/NASA has been very clear. There will be foam falling off. It is "fixed" in the sense that large pieces should hopefully not fall off. This piece (O2 connector near the front bipod) is exactly what the ET folks had expected would come off (i.e., size, location).

 

[radarredux]

>> <i>"I thought the foam problem would be fixed by now, and if it can't be fixed, either fly anyway or cancel the program. "</i><br /><br /> /> <i><font color="yellow">No, Griffin/NASA has been very clear. There will be foam falling off. It is "fixed" in the sense that large pieces should hopefully not fall off.</font>/i><br /><br />The CAIB report called for fixing the the ET so no foam would come off. O'Keefe said that all CAIB recommendations would be met before the Shuttle flew again. Unfortunately that recommendation cannot be met because of fundamental technical limitations, and I think Griffin is right to say they are "recommendations" and not "requirements". Otherwise, the <i><b>only</b></i> option at this point would be to cancel the Shuttle and probably ISS.<br /><br />I think Griffin is right to make the call that he did.<br /><br />The only change I would make at this point is: Given that tank filling and draining seems to have a negative effect on the foam, <i>don't even fill the tank unless the weather predictions are for at least a 60% chance of good launch conditions.</i><br /><br />For example, I heard/read that for July 4th there is only an estimated 40% chance of good enough weather. Given these numbers, I would say don't fill the tank and risk more foam damage.<br /><br /></i>

 

[CalliArcale]

Not sure, but I know they do have a limit on the number of tanking cycles an ET can be allowed to endure based on metal fatigue.<br /><br />More details are out now. It is believed that the piece found on the MLP is from the crack near the LOX feedline bracket. It is further believed that rainwater got in during one of the launch attempts, froze, then snapped off, taking some foam with it, when the tank expanded and the feedline flexed during detanking operations. The piece of foam is much smaller than the foam shedding limits that have been set, but it is not yet clear whether or not that's significant for deciding whether to launch as-is or attempt repairs. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[gawin]

I want to see the shuttle fly again..... but back to what i said in a post a few months back.<br /><br />When NASA tested the tank in a wind tunnle they neither filled it nor put it on a shaker table. All the test did was blow wind at the tank. Wind alone will do very little. But add all 3 wind, temp, vibration and they would have gotten as close to a real world test as possable and probably avoided this NEW PR Black Eye.<br /><br />The press is having a field day with this. 2 engineers say NO-GO because of the foam. Now cracks and chunks are found.<br />