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Author
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Topic: CAIB/SwRI foam impact tests
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Paul78zephyr
Member Posts: 246
From: Hudson, MA
Registered: Jul 2005
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posted May 01, 2007 09:34 PM
  
At this site: http://www.nasa.gov/columbia/caib/html/movies.html the last two videos are of external and internal views of FI test on RCC panel 8. Why are the times stamps of the two videos not synchonized? (Im assuming - based on the captions - that these videos are of the same test, just seen from outside and inside). I would think that synchronous time stamps would be very important to analysis of these videos. Also in the third video down (camera E212) why does the ET foam appear to move upwards at first? Where is frame 4918? And why does the shuttle appear to be rocking back and forth (ie is this camera distortion)?
Thanks,
Paul
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mjanovec
Member Posts: 3391
From: Midwest, USA
Registered: Jul 2005
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posted May 02, 2007 10:46 AM
quote:
Originally posted by Paul78zephyr:
Also in the third video down (camera E212) why does the ET foam appear to move upwards at first?
I would have to guess that the slipstream coming over the nose of the ET, then pasing the nose of the orbiter is somewhat turbulent. Note that the foam originates close to the nose of the orbiter at the attach point. I suspect we're just watching the foam follow the slipstream. Plus, the actions of the airflow on a large, irregularly-shaped (and light) object can cause erratic motions as well. As the piece tumbles, each surface is catching the airflow differently. |
Paul78zephyr
Member Posts: 246
From: Hudson, MA
Registered: Jul 2005
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posted June 23, 2007 09:52 PM
Anyone? Especially on my 1st question considering as these foam impact test videos were of the 'key' test that determined once and for all (according to CAIB) that the foam was the cause of the entire disaster. I cant believe that they would not have made certain that the two views of the same test had the same time stamps for analysis. I know this is 'old news' and many of us would like to put Columbia behind and go forward but I came across this recently and it is bothering me. Any input is really appreciated. Thanks,
Paul |
Robert Pearlman
Editor Posts: 23493
From: Houston, TX
Registered: Nov 1999
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posted June 23, 2007 10:45 PM
quote:
Originally posted by Paul78zephyr:
I would think that synchronous time stamps would be very important to analysis of these videos.
As the point of this test was to demonstrate that the foam could indeed create a significant size hole in the RCC, which it did, I am not sure how important the exact timing of the impact was to investigation board. They weren't dissecting the RCC to learn how it fell apart, only demonstrating that it could.That said, were the timing important, I believe it would be a rather simple procedure to time sync the two videos, regardless the descrepencies between their internal timers. |
Fra Mauro
Member Posts: 782
From: Maspeth, NY
Registered: Jul 2002
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posted June 25, 2007 10:09 PM
Since we are on the topic of ETs, I have a question---If all tanks had continued to be painted would foam debris been a problem at all? |
Robert Pearlman
Editor Posts: 23493
From: Houston, TX
Registered: Nov 1999
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posted June 25, 2007 10:18 PM
quote:
Originally posted by Fra Mauro:
Since we are on the topic of ETs, I have a question---If all tanks had continued to be painted would foam debris been a problem at all?
The paint that was applied to the external tanks for STS-1 and STS-2 did not stop foam from falling off. NASA recorded just as much foam loss on the first two flights as was later seen with unpainted tanks. |
garymilgrom
Member Posts: 1046
From: Atlanta, GA, USA
Registered: Feb 2007
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posted June 26, 2007 07:43 AM
Paul - I don't think the foam is moving upwards at the start, I think it is moving sideways. If it moves from right to left across the frame this could be seen to be an upward movement because of the angle of the camera. |
Paul78zephyr
Member Posts: 246
From: Hudson, MA
Registered: Jul 2005
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posted June 26, 2007 09:16 PM
quote:
Originally posted by garymilgrom:
Paul - I don't think the foam is moving upwards at the start, I think it is moving sideways. If it moves from right to left across the frame this could be seen to be an upward movement because of the angle of the camera.
In the second video down in the above link (Camera 208) the foam can clearly be seen as moving upwards in that video as well. When you watch both the camera 208 and 212 videos play them frame-by-frame. In the 212 video I think you can even see some dark colored debris (pieces of RCC???) along with the impacted foam in frames 4924-4926. Paul
Edited by Paul78zephyr |
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