Observation on TPS damage on Orbiter

NASA photos | 2-3-03 | BoneMccoy

[Cold Heat]

Not familiar with airframe behaviors.

I do know that they can pickup quite a charge, but bleed offs are installed to minimize it and the electrical systems are shielded.

The airframe makes a damn good conductor, and lightning generally passes through without damage.

Anything can happen with the stuff, but damage in modern craft is somewhat rare and they learn from every experience.

It would not surprise me to have quite a corona formed around the craft during reentry. What was captured could have been a discharge to air from the craft when it found a path.

[Cold Heat]

NASA studying Columbia photos
S.F. astronomer's is among those looked at by newly created panels
Sabin Russell, Chronicle Staff Writer

Tuesday, February 11, 2003


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NASA investigators of the Columbia space shuttle disaster have set up a study group to analyze a photograph, taken by an amateur astronomer from a San Francisco hillside, that appears to show a bolt of electricity striking the doomed orbiter as it streaked across Northern California.

General Michael Kostelnik, deputy associate administrator for the shuttle program, told reporters in Washington, D.C., Monday that "the lightning-strike photo . . . is being studied carefully to see what it means."

Separate study groups, consisting of both government and private experts, have been convened to analyze the San Francisco photograph and an image taken by a sophisticated tracking camera at Kirtland Air Force Base that was following the shuttle as it passed over New Mexico.

The Air Force shot shows a silhouette of Columbia with apparent damage to its left wing. Kostelnik confirmed Monday that a piece of the shuttle's left wing was found on the ground near Lufkin, Texas.

NASA is pooling the images from amateur videotapes, amateur photos and data from secret government cameras, and attempting to correlate them with data transmitted from the stricken craft to piece together the sequence of events that led to Columbia's breakup over Texas on February 1.

"We're looking at all the events during that time period," Kostelnik said.

In addition to visual images, investigators are poring over radar data and tapes from a bank of exotic "infrasonic" sensors that can actually pick up the noise of the space shuttle's re-entry over California. If the San Francisco photograph does indeed depict a bolt of electricity in the ionosphere, the "infrasonic" sensors in Colorado might be able to detect the faint thunderclap that accompanied it.

The San Francisco photograph, which has not been released publicly by the astronomer, was transmitted directly to the shuttle's chief engineer Ralph Roe Jr. on February 4, and a copy of the image, as well as the camera that took it,

were flown to Houston the next morning.

At previous press conferences, NASA officials have said they were trying to assess the "validity" of the image, which was taken during the time when sensors on the shuttle's left wing first showed indications of a problem.

On Thursday, shuttle program manager Ron Dittemore said there were no indications, based on flight data transmitted from Columbia at the time the photo was snapped, that the orbiter had experienced any unusual electrical event.

"There is nothing in the data stream . . . that would cause any concern on our part," he said.

The digital photograph, the third in a series of five taken by the San Francisco astronomer as he faced the northern sky, contains many visual cues --

such as a star field -- that should allow NASA scientists to pinpoint the moment the unusual image appeared, and compare it with signals transmitted from Columbia.

An analysis presumably could also quickly determine whether the image could have been caused by a jiggling of the camera during the time lapse photograph. It was taken using a Nikon M-880 camera, using an automatic exposure, triggered by finger.

Although the astronomer refuses to release the picture, he permitted two Chronicle reporters to view it last week. In the critical shot, a glowing purple rope of light corkscrews down toward the plasma trail created by the shuttle, appears to pass behind it, then cuts sharply toward it from below. As it merges with the plasma trail, the streak itself brightens for a distance, then fades. There were no unusual images visible in the other four pictures.

NASA administrator Sean O'Keefe told reporters that the agency has quickly established a system to collect photographic information from private citizens while protecting "their proprietary rights" to the images.

"We've even figured out how to move lawyers expeditiously," he said.

E-mail Sabin Russell at srussell@sfchronicle.com.

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[Cold Heat]

The photographer invited The Chronicle to view the photos on his computer screen Saturday night, and they are indeed puzzling.

They show a bright scraggly flash of orange light, tinged with pale purple, and shaped somewhat like a deformed L. The flash appears to cross the Columbia's dim contrail, and at that precise point, the contrail abruptly brightens and appears thicker and somewhat twisted as if it were wobbling.

"I couldn't see the discharge with own eyes, but it showed up clear and bright on the film when I developed it," the photographer said. "But I'm not going to speculate about what it might be."

[snopercod]

All I know is that everything is electrically bonded to everything else. The use a milliohmeter to check the resistance when installing anything.

[computermechanic]

All I know is that everything is electrically bonded to everything else. The use a milliohmeter to check the resistance when installing anything.


That helps, do you know if the RCC is also very low resistance and is also so meticulously electrically bonded to everything else? Not knowing much of the details, and assuming some pretty wild electrical-physics could be occurring at mach 20...

a couple of scenarios I'm thinking of are something on the order of the process where an incandescent light bulb burns out, all it takes is for the filament to develop a slight weakness at one point, this causes the resistance at that point to go up, which generates more heat at that point, causing accelerated damage, resistance goes up and so on... till it burns out (the foam-cracked leading edge being the filament, and many Amps flowing thru the RCC, coming from 18,000 mph of V x B current).

Another scenario is the Tacoma Narrows bridge but in electrical not mechanical resonance, and instead of being powered by a steady wind, being powered by the shuttle's enormous velocity; the frequency being on the order on many MHz and possibly generating large heat-generating peak currents. One possible indication of these kinds of weirdness-es is that they require a signifcant amount of power to drive them, so these things would cause increased drag on the damaged side of the wing.

My basic point being, such huge amounts of energy are capable of driving a large number of errant behaviours, which all need to be controlled, but for example, what happens to the simulations when the assumption of a perfectly conductive leading-edge is no longer true?

[Cold Heat]

Static charges due to friction build up very high potentials, but the current flows do not affect a well build airframe unless bonding points are poor or the point of egress or entry is situated in a bad spot.

The current flows are no where close to the potentials, which can rise to millions of volts, but the durations are in milliseconds at fairly low amperages with respect to voltage. Plus, the behavior of the charge usually takes the easiest paths and therefore bypasses areas that may be resistive.

The same occurs in a capacitor, where extremely high potentials can be stored,but the discharge is limited to the storage capacity. If you do things to limit the storage, then the discharges are not as great but more frequent. I don't see the shuttle experiencing any more risk than a passenger liner that flies millions of miles over it's career.

I do not know what the factors are,but I can assure you that they have a good handle on this risk.

[snopercod]

I can't speak intelligently regarding your theory on the RCC, but remember the "Italian Yo-Yo" tethered satellite experiment?

[computermechanic]

Thanks for reminding me of that, this $450 million, half-ton satellite complete failure, clearly proves that *NASA does not understand* high speed, high altitude electrodynamics.

Pictures of the still-glowing, 0.1 inch wide, 12 mile long, tether trailing the half-ton satellite, 50 miles up:



http://www.enterprisemission.com/tmm0013.html



Also, from a NASA teaching publication about predicted power generation from the Tethered Satellite experiment:

www.jsc.nasa.gov/er/seh/Tethered_Satellites.pdf

The Lorenz Force

An electron passing through a magnetic field experiences a force that is perpendicular to both the direction of motion and Earth's magnetic field.

BxVxL = voltage

Earth's magnetic field x velocity of tether x tether length = voltage

3x10-5 tesla x 8,000 meters per second x 20,000 meters = 4,800 volts


So if the wingspan (24 meters) is substituted for the tether length we get:

3x10-5 tesla x 8,000 meters per second x 24 meters = 5.76 volts

Now this doesn't sound like much, but the resistive load of a metal/carbon-comp shuttle wingspan is maybe 0.1 ohm to 1 ohm?

So approx 5.8 to 58 amps(?) could be flowing thru the wingspan; some of my questions would be *where* did this current flow in Columbia's cracked wing from physics we understand, and what of the electrodynamics we don't yet know about?

[XBob]

Some interesting points to ponder which I don't think we really have discussed.

So, actually, in determining the reason for the loss of the Colombia, we need to consider not only aero-dynamics, and thermo-dynamics, but also electro-dynamics.

Any more 'dynamics' we should consider?

[Cold Heat]

Let's just pretend that your figures are correct for a moment and say that at.1 ohm your (I) would be 57.6.

A piece of 10ga wire could easily handle that current load without failure.

The airframe, BTW would ohm out far in excess of .1.

Aluminum has a "K" of 17.0/ft., Monel is 25.3 . These are the bulk of the airframe metals. (copper has a K of 10.8/ft)

(BTW, K =Ohms per 1 foot x 1 mil dia) We use this figure to determine resistances in estimating specific resistances. You need to quantify it on each part with diameters and specs to figure estimated totals. A piece of aluminum conduit, 10 feet long W/O fittings at .5 in dia has a resistance of a couple hundred ohms, the last time I ohmed one out.(been a while)

I guess what I am trying to get across to you is that you are fearing things that are unlikely, if not impossible.

As I said earlier, airframes and their related electronics are well thought out when it comes to electrons. That is what aviation electrical engineers do. I just mess with the stuff on the ground. We have similar difficulties in power plants however.

That is why we lay out ground grids, lightning arrestors and shunts to deal with HV spikes and the like.

Aircraft are built to even stricter tolerances and planned for events.

[Cold Heat]

Nasa said their instruments showed no abnormal electrical behavior.

[Cold Heat]

Ooops, I made a boo boo.The K of monel is 253, not 25.3.

This is important, because monel is used as a fitting in the shuttle. It holds much of the shuttle subsections and other parts together IIRC. They also use other alloys of it that have higher ratings as being almost a dielectric.

[RadioAstronomer]

Aircraft are built to even stricter tolerances and planned for events.

Indeed! Remember Apollo 12? Struck by lightning twice on ascent. Survived just fine.

[XBob]

4512 - monel is specifically important, as it is what the bolts on the RCC segments - leading edges which take the most heat.

[Cold Heat]

Yes, and if alloyed with nickel for example, its resistance increases dramatically to the range of K/ohms.

While it is not dielectric, it becomes insinuative and is as a medium resistor to dampen electrical transference from the skin. It can be used to direct any current flow.

Electricity also has another property that we use the knowledge of.

For some reason it travels along the surfaces of any conductive metal. Even with copper wire. Which is why stranded wire has a higher ampacity than solid of the same diameter.

In a plane, or the shuttle, it remains mostly confined to the skin in it's outermost layer. Resistive connections between the skin and the airframe are all it takes to direct something like a lightning strike from getting inside the craft. Further measures are taken to protect the inside at various levels, making a layered protective envelope.(especially fuel tanks) But the static charge is seeking a opposite charge and has little need to go further than the skin.

Like a thermos bottle, nothing gets in or out electrically. The skin however will collect charge that needs to be bled to ground before touching the craft. This is true with nearly any aircraft, but the shuttle is in a class of it's own regarding this and radiation.IIRC.

Accidents do happen. Sometimes scorch marks can be left on the skin. Sometimes instruments are affected with the modern digital sensitivities, but crashes are extremely rare, even with the cheapest and unprepared of aircraft however.

I am not a aerospace engineer, so I am not knowledgeable of what precautions other than the obvious that they might take. But I would look at the recovered recorders and the received data for any evidence of stray electrical activity in the ship. It would be the first place it would show up and it would be very obvious and system wide. From what I can gather, there is none.

That is why I am not convinced of any electrical causal relationship to the loss.

[Cold Heat]

insinuative=insulative

[tubebender]

Have you seen this... http://www.local6.com/news/3975391/detail.html

[computermechanic]

Here's a photo of the purple corkscrew and some commentary:

http://www.rense.com/general63/shut.htm

"Most shocking of all is the explanation given by experts who examined the photograph. They said that the luminous corkscrew trail was an "artefact" caused by a camera wobble. The explanation left critics aghast, since the Columbia trail in the photo is crisp with no evidence of camera movement."

[computermechanic]

http://www.thunderbolts.info/tpod/2005/arch05/050223columbia.htm

Here's some speculation, perhaps someone out there has some high-altitude physics background?

What happens if the ionized trail of the shuttle comes sufficiently close to the ionized trail of a re-entrant object such as a meteor? Is the trail of the shuttle positive or negative and of what magnitude? What about the meteor?

The corkscrews make perfect sense when you consider large currents flowing in the earth's magnetic field with a rarefied gas medium, I was taught about them long ago in college. Could the thin very straight portion be a meteor-path (certainly not a current in a magnetic field!) and the corkscrews emanating from the ends massive currents?

Could the meteor trail have a greatly different charge on it than the shuttle's trail? Charge travels and accelerates freely in these rarefied gases. Can the speed and direction of the charge be calculated by the size of the spirals? I think maybe they could be.

Remember the failed "Tethered Satellite" experiment?

[tubebender]

Wasn't there some video that survived impact that showed a couple of crew members and they commented about the bright flashes that could be seen outside the craft over the eastern Pacific? It was thought it was the heat shield heating and glowing but they were startled by brightness...