# Where is Electric ground comes in missiles and rockets using high voltages ?

I may sound silly. I think that the Rocket systems and missiles might be having high power amplifiers and circuits inside them. Then how the Electric ground is accommodated in those kind of circuits. I have heard about floating ground but I am not sure whether that concept applies here.

• Ground is nothing more than just a common point with a reference potential taken as 0V. – Eugene Sh. Jul 19 '16 at 14:01
• Read this question electronics.stackexchange.com/questions/51478/… – Sean Houlihane Jul 19 '16 at 14:03
• Same as how they do it in your calculator, in your mobile phone, in your MP3 player, in your laptop, in a blinking taillight you put on your bike, and in all battery-operated equipment. They just decide it's somewhere (usually the minus pole of the battery). – dim lost faith in SE Jul 19 '16 at 14:18
• Nah they use a long wire that trails out behind. – Andy aka Jul 19 '16 at 14:36
• It´s called a sky-hook! :) – F. Bloggs Jul 19 '16 at 17:53

Ground (separate from earth) is an arbitrary point in a circuit which is chosen to be 0V. All other potentials in the circuit are then referenced to this arbitrarily chosen 0V. Ground does not have to be the lowest voltage in a system.

Earth on the other hand is typically a low impedance, high current conductor stuck literally into the earth.

To answer your question, the ground in a missile could be any point in the circuit that the designers chose to define as 0V. A "floating ground" is usually meant to indicate that the chosen point is not "tied" to earth (the physical conductor buried in the ground).

Always remember voltage is the difference in electric potential between two different points and not an absolute value like current (the flow of a discrete number of electrons).

There's a long, long wire that connect the missile to the earth. :-)

No, serious, all the voltage are floating, but referred to the "chassis" or any equipotential point used as reference.

I think that the principle is the same as in automotive (and in all battery-powered systems).

Remember, voltage is always a difference (in Italian is common to see voltage indicated as the acronym "ddp", that means "differenza di potenziale", potential difference in english, and this really helps the understanding).

• This comment maybe off-topic. Your 1st sentence I can't forget. When I'm closing eye the scene I'm seeing. :D – Always Confused Jul 19 '16 at 16:47
• Wire-guided missiles definitely exist, such as the TOW anti-tank missile :) – pjc50 Jul 19 '16 at 21:21