Pal ramp testing question

[gawin]

I was just reading the article about flying the shuttle with out the pal ramp foam installed. <br /><br />they talked about wind tunnel testing.<br /><br />My question is this and hope that some one in the know will have the answers.<br /><br />during this test will the tank be filled and will it also be on a shaker table to simulate the temperature difference between internal and external that may have a contributing effect on the cracks and will the shaker table if used be set to the forces exerted during the entire launch to tank separation.<br /><br />after working in the testing field for many years i ask this for the simple fact that if they do not do these 2 things they are literally just wasting time and money on a test that will prove nothing.

 

[gawin]

"Full or empty, it is the previously untested shape that matters."<br /><br />this is only partially true<br /><br />you need to also test under flight conditions to see that if by removing the foam from that area that you now may have created a week point some where down wind for that spot.<br /><br />just a possible situation that could arise. with the removal of the pal ramp you now have air currents hitting another area of the foam that it did not hit before. if this foam is weekend or its adhesion is lessened do to temperature differences, is effected by vibration or a combination of both this could lead to more large chunks of foam coming off. failer to test the system under as close to flight conditions as possible is being negligent at the least and at the worst putting more lives in danger that need not be.<br /><br />this is not the first time they have deviated from proper testing procedures. If they had bothered to test the tank after spending all the money redesigning it under near real world tests they would have found that the pal ramp was still having problems and they would not have had the near miss that they had on the last flight that once again caused the fleet to be grounded. Thank god it was only a near miss and did not cost more astronauts their lives.<br /><br />I have seen case after case where property or lives were lost over not following proper testing standards. computer and engineering models are great for what they are but in no way shape or form should they ever replace real world or as near to real world testing as feasible.

 

[ehs40]

"The PAL ramp was added to the external tank early the program's history to provide a windbreak for a cable tray that runs along the tank."<br /><br />http://www.space.com/missionlaunches/051202_shuttle_rtf_palramp.html<br /><br />if the shuttle has flown without the pal before shouldnt it have no problem doing it again? if early in the history of the program means before a launch i see the reason for many hours of wind tunnel testion but if it has launched before without it we should have the data and can use that now

 

[askold]

How much time and money has NASA spent fiddling with this little piece of the tank? And we're to believe that NASA is capable of flying to Mars in a couple of decades?<br /><br />To get to Mars we have to develop hundreds or thousands of new technologies each of which individually are probably more complicted than these PAL ramps.<br /><br />It's really discouraging to watch NASA these days.

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>if the shuttle has flown without the pal before shouldnt it have no problem doing it again? if early in the history of the program means before a launch i see the reason for many hours of wind tunnel testion but if it has launched before without it we should have the data and can use that now<p><hr /></p></p></blockquote><br /><br />I agree, which is why I suspect it has never flown without the PAL ramp.<br /><br />Maybe shuttle_guy can enlighten us? <img src="/images/icons/wink.gif" /> <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>

 

[digitalman2]

IBM has a 91 Tflops computer sitting around in their TJW research center, perhaps they can help ...

 

[CalliArcale]

It's unlikely to be a matter of raw computing power anyway; there's more to number crunching than just unleashing a computer on the data set. You have to work out exactly what you want the computer to do with the data, and then once its job is done, you have to work out what the results mean and make a decision. I expect that will be the slow part, not the actual processing. <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>