Observation on TPS damage on Orbiter

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.

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.

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.

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.

My line of thinking is to the large object seen shedding over Ca & Az, & left wing drag, etc. The left gear door seems a possibility. The tire exploding was a thought as to cause.

Perhaps tiles peeling back to the wheel well led to a breach by plasma which did the rest ?

The sensor time line indications are suspect to their accuracy as to the story they tell IMHO... because they do not reflect the pending disaster. In other words, a first conclusion is to give them merit as to reality (the obvious facts).

Not to say- take them with a grain of salt, but, is the information that they are relaying telling us what's actually happening ? Do you follow my logic ? I am not looking specifically for a rebuttal to the- burst tire knocking the gear door off theory, but, in a broader sense- 2 + 2 doesn't equal 4. Why ?

Thought I would add this to this thread.

Panel Seeks to ID Object Near Shuttle / STS-107
Yahoo! News ^ | 2/9/03 | Marcia Dunn - AP

Posted on 02/09/2003 1:18 PM CST by NormsRevenge

SPACE CENTER, Houston -

Investigators are trying to identify an object spotted near Columbia shortly after it reached orbit as they try to determine what caused the shuttle to break apart.

Retired Adm. Harold W. Gehman Jr., who is leading an independent board investigating the disaster, told reporters Sunday that the tracking data from the U.S. Space Command Center in Nebraska could potentially be water that is routinely dumped from the shuttle, which then turned to ice.

"It could well have been an on-orbit piece associated with the shuttle which was supposed to have been there," Gehman said. He stressed that the report still needs to be analyzed.

Meanwhile, investigators continued to study a 2-foot section of Columbia's wing and a 300-pound object that appears to be a door panel from one of the shuttle's wheel wells found in Texas.

The wing includes the carbon-covered edge designed to protect Columbia's insulating tiles during re-entry and could provide hard evidence of what went wrong, NASA (news - web sites) Administrator Sean O'Keefe said Saturday.

Gehman would not comment Sunday on whether the wing piece was from the shuttle's left side, which could prove significant because Columbia's troubles began in the left wing.

In the shuttle's final eight minutes the morning of Feb. 1, temperatures surged in the left landing gear compartment, and the brake lines began overheating one by one. Sensors began showing overheating across other areas of the left wing and adjoining fuselage before Mission Control lost all contact.

O'Keefe spoke following a memorial service at Louisiana's Barksdale Air Force Base, where pieces of the shuttle are being stored. Searchers have recovered remains of all seven astronauts and more than 12,000 pieces of debris that rained down across two states.

Every possible scenario is still being considered, from the impact of a large chunk of hard insulating foam that hit the shuttle seconds after liftoff Jan. 16, to a strike from a piece of space junk, to a lightning-like electrical phenomenon.

Late Saturday, NASA said the U.S. Strategic Command apparently tracked something flying near Columbia after it had reached orbit. Space agency spokeswoman Eileen Hawley said it was possible the object came from Columbia, but stressed "this is very raw data" that had just been turned over to investigators and that it was too early to speculate.

Imagery experts also are poring over a high-resolution photo taken by an Air Force telescope a minute or two before Columbia broke apart during re-entry. Some have suggested the leading edge of the left wing looks as if it could be damaged, and the photo shows a gray streak that could be a fiery plume trailing the wing.

NASA continues to gather evidence through an extensive debris search, centered primarily in Texas and Louisiana.

Meanwhile, about 1,000 people gathered Saturday in a church across the street from the debris search command center in Lufkin to remember the astronauts as a fun-loving but heroic group.

NASA astronaut Jeff Ashby, who recalled visiting the crew's lively table at the NASA Christmas party, said the crew was a generous, caring bunch with a great sense of humor. "They actually baked cakes for their training instructors on their birthdays," he said.

Gov. Rick Perry told the group at the First Baptist church that the astronauts "remind us that the future belongs to the brave and the bold."

In Hemphill, searchers also paused to observe the exact moment the shuttle broke up a week before. "There was total silence in the room, about a minute, and then we went on with life," said Marq Webb, U.S. Forest Service spokesman.

___

On the Net:

NASA: http://spaceflight.nasa.gov

Thanks-

There is some merit to the- 'gear door open creating drag' theory. Thus my pursuit of cause and effect.

If the ship was traveling at 100 mph, an open gear door would have one kind of effect on it's aerodynamic properties, and if the ship was traveling at 1,000 mph, an open gear door would have another, completely different kind of effect on the aerodynamic properties of the shuttle.

Finally, if the ship is traveling at 12,000 mph, an open gear door would have an effect wholly unlike the previous two examples.

Because the ship is traveling at 12,000 mph, there is ample (understatement) relative wind 'rushing by' to use for flight control purposes. The high forward speed negates the absence of atmosphere at 200,000-400,000 ft. a.g.l.

If a door came open, more than likely it would be ripped off. It may have acted rudder like to the ship (likely ripped off still) for a brief moment. This may have led to drag problems, or worse.

I don't know- the first three sensors to show an anomaly were in the gear box...

To sum up the old ball game to this point-

foam / foam-ice combo. debris, strikes / damages...

glove area of left wing
TPS @ underside of left wing, near glove or near wheel well
RCC @ leading edge of left wing

plasma penetrates left wing...

@ RCC leading edge left wing seam
@ pinhole or larger in RCC leading edge left wing
@ vortex or eddy in anomaly in TPS tile underside left wing
@ missing TPS tile underside left wing
@ gear door cover underside left wing
@ left wing inboard outboard elevons

drag and / or possible loss of flight aerodynamics and / or wing destruction path...

deformed leading edge left wing @ glove area
deformed leading edge left wing @ 1 or more RCC's
left wing gear door cover open attached
left wing gear door cover open detached
penetration / damage underside left wing
deformed or inoperable left wing inboard outboard elevons

loss of vehicle...

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