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Observation on TPS damage on Orbiter
NASA photos | 2-3-03 | BoneMccoy

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.


TOPICS: Breaking News; Editorial; Extended News; Front Page News; Government; Miscellaneous; News/Current Events; Your Opinion/Questions
KEYWORDS: columbiaaccident; nasa; shuttle; sts; sts107
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To: halfbubbleofflevel; XBob; bonesmccoy; Thud; All
Half sent me his 3D program. Unfortunately Fotki won't accept it. I originaly thought it vwould.

Bones, xBob, everybody, it is an excellent tool that would be very useful in all our analysis. you may want to FReep-mail him to get it.

I had no trouble at all running it under XP Pro.

Must now leave for work.

1,581 posted on 02/13/2003 12:36:05 PM PST by Budge (God Bless FReepers!)
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To: freepersup
1578 - great animation, Freepersup! I'll Check back later.
1,582 posted on 02/13/2003 12:41:19 PM PST by Budge (God Bless FReepers!)
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To: XBob
FYI.......The photo showing the flareing object with the 7:55.53 time stamp is a capture from the video those kids took. Their location was in AZ.
1,583 posted on 02/13/2003 12:53:51 PM PST by Cold Heat
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To: Budge
Update: I just finished adding in F1 to save the resultant image in a tga file. Let me know if you want it, any changes or additions, etc.

We still have to find a way to distribute it to any interested parties.
1,584 posted on 02/13/2003 1:59:28 PM PST by halfbubbleofflevel
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To: wirestripper
I think they reported the "failure" of the gear down sensors, not that the sensor indicated that the gear was down. It was also very late in the time line.
1,585 posted on 02/13/2003 2:10:36 PM PST by John Jamieson
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To: John Jamieson
I think they reported the "failure" of the gear down sensors, not that the sensor indicated that the gear was down. It was also very late in the time line.

Actually, they said what they said, but have not said it again, at least while I was watching.

I don't know if they misinterpreted the report or what.

Yes, it would have been late in the time line if a time is stated, but so far nothing more. If the gear came down, it would likely be within 15-30 seconds before breakup.IMHO

I guess a developing story is the word to use.

1,586 posted on 02/13/2003 3:15:02 PM PST by Cold Heat
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To: XBob; wirestripper; Thud; BraveMan; All
Don't laugh XBob.

TPS did it's job. Why are you and Jamieson so interested in embarassing the Rockwell/Boeing TPS guys?

You've managed to explain the loss of the orbiter with a reasonable hypothesis.

However, the hypothesis for failure of the structure is incomplete without focusing attention on the ET insulation.

Something clearly fell from the ET intertank region. What was it?

My original posting was to request that colorimetric testing be completed in order to evaluate the composition of the debris cloud seen at the end of both videos posted by NASA.

Since NASA was originally stating that there was no correlation between the debris impact and the TPS damage, it left NASA with an out. The out was that poor work by Boeing/Rockwell TPS was responsible for loss of the vehicle. I can not accept that hypothesis.

Thud located a remarkable email where USA's TPS guys hypothesized a failure mode. We do not believe that rapid decompression/explosion of tires were involved in loss of the MLG door prior to 57 minutes.

One wonders if the tires were lost between 56:30 and 58:00 and lead to a blown MLG Door assembly at 57-58:30 mins.

1,587 posted on 02/13/2003 3:25:26 PM PST by bonesmccoy (Defeat the terrorists... Vaccinate!)
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To: bonesmccoy
Something of size came off while over AZ. The video the kids took prooves it to me.

Whether their time set on the camera was accurate, we do not know. It would not surprise me is it were off by a minute, more or less.

1,588 posted on 02/13/2003 3:36:01 PM PST by Cold Heat
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To: bonesmccoy
poor work by Boeing/Rockwell TPS was responsible for loss of the vehicle. I can not accept that hypothesis.

I do not think anyone has said that.

The TPS system has it's fragilities. Impacts from debris is just one of them. (Spitting on the RTV didn't help much)

The fact that the engineers did not have any experience with a foam strike of this size puts it out of their range to carefully estimate.

As you stated, it all goes back to the tank, the foam, the age of the tank. The weight and tank design.

1,589 posted on 02/13/2003 3:43:02 PM PST by Cold Heat
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To: wirestripper; XBob
Gee... are you serious?

We've been saying that the numbers looked like the MLG door was down at 57:30 or so.

We'll see what they say.

I'm betting that the MLG door was down, but XBob still may be correct regarding loss of the RCC/LH Wing leading edge structure.

I disagree with his assessment of the LH wing glove being missing and have been stating so.

Regretably, I do not have the graphics programs to manipulate the USAF photo and the tile diagram.

Hopefully I can locate a 3-D model for the orbiter and see if the MLG door could be open in the photo at the angle suggested by XBob.

XBob says the orbiter is overhead.

I was thinking not. The orbiter must be at a specific angle to the horizon... 45-50 degrees?
1,590 posted on 02/13/2003 3:49:05 PM PST by bonesmccoy (Defeat the terrorists... Vaccinate!)
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To: John Jamieson; All
NASA confirms one sensor aboard Columbia indicated landing gear was lowered

Associated Press



WASHINGTON — NASA confirmed today that one sensor aboard Columbia indicated its left landing gear was improperly lowered moments before it disintegrated over Texas. But the space agency said other sensors conflicted with those readings.

The disclosure focused renewed attention on possible catastrophic failures inside Columbia’s wheel compartment inside its left wing that may have attributed to the mysterious breakup.

Safety engineers believe an unusually large chunk of flyaway foam from Columbia’s external tank struck the shuttle on liftoff and may have damaged delicate insulating tiles near that area, but they concluded Columbia could return safely.

NASA spokesman William Jeffs at Johnson Space Center confirmed that one sensor indicated Columbia’s gear was lowered as it raced over Texas at 209,000 feet and flying at 18 times the speed of sound — far too high and too fast for that to happen. But Jeffs cautioned that two other sensors at the time indicated the gear was still properly raised.

“We’re not certain if the readings showed the landing gear deployed or were the result of a faulty sensor that sent bad data,” Jeffs said. “One indicated (the wheel) was down and locked, and that was shortly before radio contact with the orbiter was lost.”

NASA disclosed Wednesday that a safety engineer wrote two days before Columbia’s mysterious breakup about risks to the shuttle from “catastrophic” failures caused by tires possibly bursting inside the spacecraft’s wheel compartment from extreme heat.

Robert H. Daugherty, responding to an inquiry from Johnson Space Center, cautioned in an e-mail to NASA colleagues that damage to delicate insulating tiles near Columbia’s landing gear door could cause one or more tires inside to burst, perhaps ending with catastrophic failures that would place the seven astronauts “in a world of hurt.”

Such an explosion inside Columbia’s belly, Daugherty predicted, could blow out the gear door and expose the shuttle’s unprotected innards to searing temperatures as it raced through earth’s atmosphere.

Ret. Admiral Harold Gehman, who heads the panel investigating the Columbia accident, today called Daugherty’s e-mail “one of the many, many interesting leads that we have.”

On the same day NASA disclosed the contents of Daugherty’s e-mail, searchers near Hemphill, Texas, about 140 miles northeast of Houston, recovered what they believed to be one of Columbia’s tires.

The tire was blackened and sustained a massive split across its tread, but it was impossible from photographs to know whether the tire was damaged aboard Columbia or when it struck the ground.

NASA officials in Washington and Houston today said they could not confirm the tire was the shuttle’s, but one person familiar with tires on the orbiter looked at a photograph of the tire found in Texas and said it appeared to be from a shuttle.





1,591 posted on 02/13/2003 3:49:37 PM PST by Cold Heat
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To: freepersup
Your composite image was a brilliant idea. You should send it NASA, Fox News etc.
1,592 posted on 02/13/2003 3:54:08 PM PST by Jeff Gordon
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To: wirestripper; XBob
wow... we were right!

The USAF photo DOES show the LH MLG door is down!
1,593 posted on 02/13/2003 4:05:39 PM PST by bonesmccoy (Defeat the terrorists... Vaccinate!)
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To: wirestripper
http://www.orlandosentinel.com/news/custom/space/orl-asecssmsensor13021303feb13,%5C0,1610938.story?coll=orl%2Dnews%2Dheadlines

exerpt follows:

A sensor indicated shuttle Columbia's left landing gear was down and locked 26 seconds before radio contact with the orbiter was lost, according to internal NASA documents obtained by the Orlando Sentinel.

If the sensor reading was accurate, it signaled disaster for Columbia, which broke apart above central Texas on Feb. 1, killing seven astronauts. However, at the same time, two other sensors were indicating the landing gear was safely retracted in Columbia's wheel well.

Engineers aren't certain if the reading showing a deployed landing gear was real or the result of a faulty sensor that sent bad data as the ship's systems began to fail.

The document obtained by the Sentinel is the first time the data from the landing-gear sensor have been made public. Though NASA in the past week has released information about 17 other sensors that showed abnormal readings during the shuttle's final moments, officials have said nothing about the possibility that the landing gear may have suddenly deployed.

"There is nothing sinister about this at all," NASA spokesman Kyle Herring said. "They think this was a sensor reading and not an actual event."

The landing-gear sensor is yet another puzzle for investigators to solve as they try to determine what brought down the shuttle. Engineers are focusing on what happened to Columbia's left wing and the left-side wheel well, both of which apparently were struck by a doormat-sized chunk of insulating foam that peeled off the shuttle's external fuel tank during liftoff.

As the shuttle continued its fiery descent over California shortly before 9 a.m. on Feb. 1, sensors began shutting down or displaying temperature increases of up to 40 degrees in the left wheel well.

The new timeline, as well as other information obtained by the Sentinel, indicate that the Mishap Response Team investigating the disaster may be making some progress in understanding what happened.

For example, a new study looking at the temperature rise in Columbia's left wheel well has concluded that only an opening in the wheel well or wing cavity could account for the rising heat shown by the sensors, said a Johnson Space Center manager who asked to remain anonymous.

One of the first indications that something was wrong aboard Columbia came at 8:52 a.m., when brake line temperatures in the left landing gear started to rise. Nine sensors in and around the left wheel well showed temperatures continued to increase.

The JSC manager said the new analysis shows that loss of the shuttle's heat-resistant thermal tiles would not be enough to account for the temperature spike. Instead, the super-hot plasma that surrounds the shuttle during entry would have to have found a way inside.

"The bottom line," the manager said, "is we had to have had plasma flow into the wheel well or wing cavity." That finding, if confirmed, could be consistent with some sort of breach in the left wheel door.

Managers learn of reading

Information about the landing-gear sensor is one of several new details contained in a confidential Feb. 11 timeline of the accident drafted by the Mishap Response Team at Johnson Space Center.

The landing-gear deployment signal had earlier appeared on an internal timeline circulated among NASA managers on Feb. 4 -- three days after the shuttle disintegrated. That timeline is similar to summaries released publicly last week showing sensors on the shuttle's left side either shutting down or registering higher temperatures. But the previously released summary stops just before a sensor began indicating that the left landing gear had dropped down.

The landing-gear sensor message came at 8:59:06 a.m. Saturday, about 10 seconds after sensors reading the ship's left landing gear tire pressures failed.

At this point in the shuttle's descent, the orbiter was still more than 200,000 feet high and moving at 12,500 mph. The landing gear is supposed to deploy at speeds below 345 mph and an altitude of 250 feet, according to NASA. Twenty-four seconds after the landing-gear signal came on, jets began firing to control Columbia's leftward drift, caused by as-yet unexplained aerodynamic drag on the orbiter's left wing. Within the next two seconds, sensors detected the maximum movement of the shuttle's wing flaps before all signals from the doomed craft suddenly ended.

The Feb. 11 timeline noted that at the time the signal was lost, the flaps' "rate of change still [was] increasing rapidly" in an effort to keep the Columbia on course.

In a briefing of reporters last Friday, shuttle project manager Ron Dittemore said NASA engineers could see that the shuttle's control system was fighting a "losing battle" against the drag on the left wing.

"Even though we were still flying straight and in a general attitude that we desired, we can see that the aero-surfaces were continuing to increase in their magnitude to counter the drag," he explained.

"The jets were firing, again to counter the drag. And when we lost data, they were still holding control of the vehicle."
1,594 posted on 02/13/2003 4:10:27 PM PST by bonesmccoy (Defeat the terrorists... Vaccinate!)
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To: bonesmccoy
Knowing hindsight is always 20/20

You would think that for $3 billion a year spent on the Shuttle program, NASA could afford a little foresight. Why couldn't NASA have done the same thing that other FReepers are doing now? The seven Columbia crewmembers would still be in orbit, not out of danger, to be sure, but still alive and capable of rescue.

1,595 posted on 02/13/2003 4:11:38 PM PST by 537 Votes (Don't let Iraq go nuclear: Fight now or glow later!)
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To: bonesmccoy; XBob; wirestripper; All
I just had another thought.

If the MLG door sensors were working until 59:00 and show deployment on one sensor, we know that the MLG door was probably not down before 56:30. If the MLG door had been compromised over California, then the MLG hydraulic temp sensors would have been compromised much earlier.

This news suggests that MLG Door failure is a late event and not a contributing factor to the initial over heating experienced by OV-102 at 54-56 minutes.
1,596 posted on 02/13/2003 4:13:02 PM PST by bonesmccoy (Defeat the terrorists... Vaccinate!)
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To: 537 Votes
Your comment is not consistent with engineering fact.

The vehicle was at the end of a two week mission, which is the longest an orbiter is capable of sustaining life in orbit.

Extension of the vehicle's mission for another two weeks would have created a tomb where the crew suffers a slow, lingering death of starvation, deprivation, and asphyxiation.

There was no choice but to bring the crew home.
1,597 posted on 02/13/2003 4:14:56 PM PST by bonesmccoy (Defeat the terrorists... Vaccinate!)
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To: bonesmccoy
You're on the same page as myself. I see the door failing after a great deal of plasma prenetration into the area in front of the door. The latches evetually burned and the door loss began. I don't think it just popped off. (Too much pressure holding it down)

If there is debris from the door, it should be in the New Mexico desert, near the texas border.(wild educated guess)

1,598 posted on 02/13/2003 4:24:24 PM PST by Cold Heat
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To: wirestripper
wirestripper,
I think we need to do a trajectory calculation based upon the velocity of the vehicle and the flight path.

I wonder if Freepers in CA/NV/AZ/NM can calculate the point of impact of the separated debris in the video from the California guy.

Let's start working the problem and guess where the object is located on the Earth.

Shall we start with the astronomical observations?

Where was the guy in California who shot the video posted above?
1,599 posted on 02/13/2003 4:29:14 PM PST by bonesmccoy (Defeat the terrorists... Vaccinate!)
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To: bonesmccoy
Extension of the vehicle's mission for another two weeks would have created a tomb where the crew suffers a slow, lingering death of starvation, deprivation, and asphyxiation.

Better a blaze of glory, I suppose.

1,600 posted on 02/13/2003 4:30:23 PM PST by null and void (*sigh*)
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