Where is ground on a spaceship!? ...a space station?

It is much appreciated.

I don't think it wise to ground to the station frame - it's sitting in a radiated environment.  Too many things could go awry, however, for the same reasons that autos use the frame ... it saves the need for additional wires.

I don't think it wise to ground to the station frame - it's sitting in a radiated environment.  Too many things could go awry, however, for the same reasons that autos use the frame ... it saves the need for additional wires.

If a space station has a conductive skin completely around it, then it will act as a Faraday Cage even in space.  Do you still think it's not wise to use this conductive skin or metal frame for protection?  Apparently the high voltage line workers think it is wise and I don't think additional wires would protect those workers or the helicopters.

There is a BIG difference between "Ground" and "Shield".  The Frame of a vehicle of any kind is a shield, not necessarily a ground.  (This is why ALL aircraft have static ports on them, but that's another story.)

There is no difference in the purpose of the earth ground or a shield.  Just because the frame isn't put into the dirt, doesn't mean it's not serving the same purpose as a 8ft. thick copper rod that is in the dirt.  They both divert as much excess external energy away as possible to prevent damage and fire to internal components. Their is no guarantee it will be successful in any system since the possibility is always there for it to jump into the internal wiring of the house or vehicles causing damage and fires.

The static ports on the airplanes is for static build up.  The aluminum skin is for lightning strikes.  Then you can have fuses and surge protectors for the inside wiring for additional protection.   Lighting rods with the large ground cables running on the outside of the house is additional protection against direct hits on the house instead of the outside service wires being hit.  Utility ground offers protection against transformers blowing, etc. The purpose of all of this is for protection and the dirt doesn't make it any more "grounded" than other methods.  Grounding means a certain level of protection, it doesn't mean the excess external energy has to be bled off into the physical ground of the dirt in order for it to be grounded or protected.

I installed satellite dishes for a number of years and I know what the purpose of grounding is and we had many options.  Grounding to cold water pipes, metal frames of mobile homes, the copper ground rod, the meter box, etc.  They all served the same purpose, to bleed off the static build up on the dish! 

Same thing with shielding the magnetic flux of a magnet.  The shield only diverts the return path of the field by allowing the flux to flow in the shielding material instead of passing through it.  If the material isn't thick enough for the strength of the field, then the field will pass through the material.  In fact, if you're trying to shield a south pole with a material, then the material must have a north pole attached to the material before the path is diverted.  My videos on how to shield the magnetic field successfully and it's the reason for so many failures because most of the time it's not done properly, http://www.youtube.com/watch?v=_81SxByRNR8 and http://www.youtube.com/watch?v=aJFgMB5ezsE


GB

You also have the "Standard" BX cable, which is the flexible power wiring with a metal encasement, which CAN be used as ground, but again not to flow a neutral.   (That is done more than you want to know...)  The Actual purpose of both of these is shielding the AC component from radiating out of the conduit, and not for grounding, but to the electricians, this IS the 3rd wire "Ground".

 I have never run conduit or any type bx cable without an insulated ground. This is code.
 I have lost a in ground water pump,2 tvs,and a stereo all at one time. My computers had surge protection so I didnt lose them. I didnt lose my 10 ft. sat dish either. I had surge protection put on for my tvs afterward. I have an Audio studio also but thats all on surge protection with a separate service so no damage there. I also have a 32 foot galvanized weather mast with no problems.
I had surge protection put in on my service meter to protect the major appliances. I wish Florida would make that mandatory. Next to Africa we get the most lightning strikes.
Here is an excellent view of lightning exiting the static wick on a plane.
http://www.youtube.com/watch?v=8o2oachaHXY

Equalizing potential differences and grounding are two different things.  The Helicopter you mention does this for safety...

I once knew someone that tested the lines like this, he mentioned a colleague that was injured because the path didn't go to the probe but decided to ground out to one of his dental fillings instead.  This doesn't stop the discharge from being unpredictable.  It seems to do what it wants.

If the car were grounded, I think the battery would leak.

The probe allows them to equalize the voltage potential.  The metal fibers in their suits is acting as the ground which allows them to work as safely as possible in this type of environment, since the energy will flow around them instead of through them.  The earth ground accomplishes the same thing, it diverts the unwanted energy away just like the metal fibers in their suits.  Grounding is about diverting the unwanted energy to a safer place in order to avoid damage, etc to sensitive equipment and life.  Both the shielding and the earth ground diverts the unwanted energy to a safer path.  They have the same purpose and accomplishing the same thing.  Both are "grounding methods".  The only difference is the terminology used across different fields, which is just a play on words.  Now, shielding can be used for other purposes also.

A car battery does have one terminal connected to the metal frame and it doesn't leak because it is an open circuit.  This connection between the battery and frame is called the "ground cable".  In order for it to leak, then both terminals would need to be connected to the frame and that would create a short and discharge the battery in a bad way.  Same thing if it was connected to an earth ground. 

Here's a link showing the battery is connected to the frame on a car.  On the link page scroll down to "Operating Instructions" and you can see they call this the "negative ground" if the negative terminal is connected to the frame, http://www.battery-chargers.com/charging_instructions.htm .  Do you see a pattern here?  The pattern is the negative ground, positive ground, neutral ground, and earth ground.  They're all describing the "grounding method"!

If you're holding the earth ground, and unwanted energy flows through it for whatever reason, then you're toast just like the guy having dental fillings.  In any grounding method, the unwanted energy can always jump to where it's not wanted, especially if you're near or part of it's path.  This is the whole purpose of diverting this unwanted energy to a "safer place" with any grounding method.  The further away you are from the path of this diverted unwanted energy, the safer you are!

Let's not over-complicate this.  Grounding is a really simple concept with many different methods using the same basic principals.

Think Auto's, and Positive Ground.  The word "Ground" technically means the "Reference" 0 Volts assumed.  We chose what that is.

It has been proven, by the way, that the "Earth"  (Commonly thought of as "Ground"...) has a reference potential relative to space normal, but that actually has no effect on our use of the "Reference" meaning, so most will accept the earth, in an unexcited state, to be "Ground".

So the shell of the car is at a lower electron density than the wiring. What happens to the electron flow between the vehicle and earth-ground, or the atmosphere?

on a space ship, they would have a sandbox.
with sand, calcium, and carbon in it.
though having some water in the sandbox, would also help.


the paramagnetism of the sand and calcium, would generate the negative magnetism.
the electrical conductivity of the carbon, would unify the sand and calcium.



if a crew member stuck a wire into the sandbox, than the wire would be grounded.
the larger the sand box, the better the grounding.