Posted on 02/04/2003 1:34:19 AM PST by bonesmccoy
In recent days the popular media has been focusing their attention on an impact event during the launch of STS-107. The impact of External Tank insulation and/or ice with the Orbiter during ascent was initially judged by NASA to be unlikely to cause loss of the vehicle. Obviously, loss of the integrity of the orbiter Thermal Protection System occured in some manner. When Freepers posted the reports of these impacts on the site, I initially discounted the hypothesis. Orbiters had sustained multiple impacts in the past. However, the size of the plume in the last photo gives me pause.
I'd like to offer to FR a few observations on the photos.
1. In this image an object approximately 2-3 feet appears to be between the orbiter and the ET.
2. In this image the object appears to have rotated relative to both the camera and the orbiter. The change in image luminosity could also be due to a change in reflected light from the object. Nevertheless, it suggests that the object is tumbling and nearing the orbiter's leading edge.
It occurs to me that one may be able to estimate the size of the object and make an educated guess regarding the possible mass of the object. Using the data in the video, one can calculate the relative velocity of the object to the orbiter wing. Creating a test scenario is then possible. One can manufacture a test article and fire ET insulation at the right velocity to evaluate impact damage on the test article.
OV-101's port wing could be used as a test stand with RCC and tile attached to mimic the OV-102 design.
The color of the object seems inconsistent with ET insulation. One can judge the ET color by looking at the ET in the still frame. The color of the object seems more consistent with ice or ice covered ET insulation. Even when accounting for variant color hue/saturation in the video, the object clearly has a different color characteristic from ET insulation. If it is ice laden insulation, the mass of the object would be significantly different from ET insulation alone. Since the velocity of the object is constant in a comparison equation, estimating the mass of the object becomes paramount to understanding the kinetic energy involved in the impact with the TPS.
3. In this image the debris impact creates a plume. My observation is that if the plume was composed primarily of ET insulation, the plume should have the color characteristics of ET insulation. This plume has a white color.
Unfortunately, ET insulation is orange/brown in color.
In addition, if the relative density of the ET insulation is known, one can quantify the colorimetric properties of the plume to disintegrating ET insulation upon impact.
Using the test article experiment model, engineers should fire at the same velocity an estimated mass of ET insulation (similar to the object seen in the still frame) at the test article. The plume should be measured colorimetrically. By comparing this experimental plume to the photographic evidence from the launch, one may be able to quantify the amount of ET insulation in the photograph above.
4. In this photo, the plume spreads from the aft of the orbiter's port wing. This plume does not appear to be the color of ET insulation. It appears to be white.
This white color could be the color of ice particles at high altitude.
On the other hand, the composition of TPS tiles under the orbiter wings is primarily a low-density silica.
In the photo above, you can see a cross section of orbiter TPS tile. The black color of the tile is merely a coating. The interior of the tile is a white, low-density, silica ceramic.
Fits my line of thinking.
I was apparently reading your mind, or you were reading mine. In any case, I note the picture was taken in California apparently.
At the time of the shuttle accident, a couple kids were filming it when it flew over some place along the Utah, New Mexico area. Their vid, (I only saw it once) showed a similar event when something came off and the plasma plume got brighter. I even thought that I saw something spinning off. (I believe I notated it somewhere on this thread, under the handle of Wirestripper)
Any how, it seems plausible.
It seems a large part of the shuttle simply burned up completely when it reentered.
All efforts to find anything have thus far been futile. Groups of folks with GPS gear have looked.
Perhaps one day, a piece of interest will show up. They have since found a bit more in Texas, but that debris is of little further interest.
There are pieces that are missing from the wing that still could be interesting, depending on where it is found,but I think we now have a good idea as to the sequence of the events.
Yes, that was on the video that survived.
According to the story with the photo, the orbiter was at 63 kilometers altitude when taken.
The Colombia (If I did my calculations right) was passing east of Abilene, TX at that altitude.
And the corkscrew contrails are much like those I saw at cape canaveral, from un-aerodynamic pieces of exploded rockets.
So, I think that there is notihing unusual here, other than the orbiter breaking up, pieces buring up, and the orbiter burning even more brightly, as a large piece broke off and it became even less aerodynamic.
ping the last post
ping
I am so tired of being screwed with these days.
ROTFLMAO - NASA has just formally announced an amazing new concept, much safer and cheaper - mounting a capsule on top of a rocket to send it to the moon. This revolutionary new concept, for the first time in 30+ years, has a reusable capsule, shich wont be subject to damage from an external tank, and which can land on the ground, and actually gives the crew a chance of escape in case of problems on liftoff.
Hardy, har har har.
our space program is now going forwards by going backwards 40 years, to the early 60's.
I wonder if they will get Marty McFly - "Back to the Future (1985)"
or perhaps - Buckaroo Banzai will be the astronaut to fly it.
Laugh while-a you can monkey boy!
That's okay, null: I got the Buckaroo Banzai reference.
"That's Big boo-TAY!"
That's okay, null: I got the Buckaroo Banzai reference.
"That's Big boo-TAY!"
I guess he didn't...
Trust me, Bob, it's funny!
I wonder if I could afford to get some of these tiles for my roof...to replace those lousy asphalt shingles!
*shrug* It was supposed to be, anyway. Sorry.
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