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Assuming the magnetorquer and the field generating electronics are both rigidly fixed to the spacecraft cube. Reference to any supporting papers/articles would be great. Thanks.

Would the residual field affect the performance of the magnetorquer due to generation of back emf. To cancel which, more current must be passed to get the same torque (in case polarity of emf is opposing) and less current in the other direction where emf polarity is favorable. Constant external field assumed.

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  • $\begingroup$ Are you looking for the theoretical existence of some torques, however small, or are you looking for some practically significant value? If the latter, you should probably clarify a bit. $\endgroup$ – Nathan Tuggy Sep 14 '16 at 5:21
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    $\begingroup$ Any torque on the magnetorquers will cause an equal and opposite torque on the spacecraft components they're interacting with; but since both are part of the spacecraft, the net torque is zero. (Otherwise you'd be able to turn "for free," violating conservation of angular momentum.) $\endgroup$ – 2012rcampion Sep 14 '16 at 8:09
  • $\begingroup$ I agree with the previous comments. I can see two other directions for your question: a) just to calibrate the unintended effects what are the effects of other current loops - either from a changing current or a steady current on a spacecraft moving through a changing magnetic field, it might be easiest to evaluate these yourself for the situation of interest as its otherwise open-ended $\endgroup$ – Puffin Sep 14 '16 at 9:16
  • $\begingroup$ b) in a more complex system where there an active control loop with some attitude sensor (possibly even a magnetometer) being used to control the magnetorquer then how would you isolate the attitude disturbances from the unintended satellite current loops so that the control loop wasn't constantly firing the magnetorquer circuit to make corrections? I don''t know what normal practice is, just putting it out there. $\endgroup$ – Puffin Sep 14 '16 at 9:18
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    $\begingroup$ @Puffin I am not using magnetometer for the closed loop attitude control. However, would the residual field affect the performance of the magnetorquer due to generation of back emf. To cancel which, more current has to be passed to get the same torque (in case polarity of emf is opposing) and less current in the other direction where emf polarity is favouring. Constant external field assumed. $\endgroup$ – IG123 Sep 16 '16 at 14:11

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