posted 06-04-2005 11:26 AM               

can everybody of the guys here, close to the cape or houston, explain, why the original sts-114-ET was testet for a second fueling test.

would´nt it be more logical to perform this test with the tank wich is now scheduled for flight in july ??

i guess it should be much more safe to know how the critical valves and sensors that failed at the first test are working at the real flight hardware ???

posted 06-04-2005 02:14 PM               

Two options include testing it on the pad and delaying the launch a few days; or conducing the second test during the countdown, two days before launch (a simulated scrub and 24 hour turnaround).

Why did they test the first one again? Well, for one thing it saved a lot of time, since they weren't going to roll Discovery back right away. Do a second test then instead of late June or early July, which would have been on top of an already very tight schedule.

So while it sat at the pad waiting to swap tanks in the VAB, they performed a second test to further understand problems encountered in the first test.

Also, it was possible that the first tank was experiencing those cycling problems because of a flaw in that particular tank, rather than the design. So conducing the test with the same tank helped validate that theory; and indeed they now believe they understand why.

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-Ben

posted 06-05-2005 09:47 AM               

thank u very much for this really interesting informations....i knew u would be the one , who can tell us the detailled stories from cape

sometimes i´m envying you...i guess ;-)

by the way....are there any plans using the original sts-114 tank for a futher flight ???

posted 06-05-2005 11:58 AM               

ET-120, which they just took off Discovery, has no plan right now. Scenarios NASA said include sending it back to Michoud, I believe.

ET-119 is the third of the new tanks to come from Michoud, and is scheduled to be shipped to KSC June 9. Right now, NASA is saying "Atlantis STS-121 will likely fly with ET-119" but no decision has been made formally yet.

I can't imaging wasting ET-120 but who knows. I don't think they have decided (formally) anything other than that Discovery 114 will fly with 120.

Confusing? Yes! :-)

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-Ben

www.LaunchPhotography.com

posted 07-13-2005 02:17 PM               

its seems that the fuel sensor problem never have been really resolved, despite of changing the ET´s.
instead it was categorized as an "unexplained anomaly".

if the proper working of these four sensors are so important during launch, how could it work to go thru a countdown with no idea, what triggered the earlier failure.

it seems, that also a sensor box plays an important role in troubleshooting the sensor problem.
the so called "point sensor box" even have been replaced more than one time after the april 14 th tanking test, when two of the sensors already failed.

does anybody have more informations about the case, that could explain what happend and why the engineers considered the problem as an unresolved anomaly and tried to take off despit this ?????????

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michael may www.ag-99.de/spacenet/main/main.html