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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?

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?

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.

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.