Propulsion is any method used to accelerate spacecraft and artificial satellites in the very simplest manner. Space travels in recent times relies on ejection of propellant which is now challenged by reachable distance of a vehicle in desirable time.
The idea proposed in this paper involved a propellant-free superconducting solenoid thruster driven by geomagnetic field. The researchers who were from National Taiwan University developed a method that uses an already available field which is geomagnetic field in space and developed a superconductor that could pass through this field thereby generating a thrust that could propel the satellite or spacecraft in space.
The method involved a magnetic dipole been created by wrapping a solenoid around an iron core. It is been varied spatially by changing the cross-sectional area of the solenoid, this in turn would help produce a gradient of magnetic dipole moment. To measure the interaction force, they developed a force sensor in terms of a cantilever connected to a capacitor. When a magnetic force exerts a bending on the cantilever that is made of thin metal plate, the capacitance is changed and can be measured with a high precision to determine the magnitude of the applied force, giving a sensitivity of 1micro-Newton. This high sensitivity for measuring a ting force enables for identification of the magnetic force on the superconducting coils caused by the weak geomagnetic field via interaction.
In this research, various mathematical simulation was used in order to verify the simulation that was put into consideration by the researchers. To verify the accuracy of the numerical simulations and identify the effects of the varying magnetic moment via the spatial gradient, the solenoid was first implemented in a non-uniform magnetic field provided by a magnet. Then a 3-D simulation showed clearly the distribution of the magnetic flux density.
Conclusion: The paper concludes by saying that if by changing the cross sectional area with readily accessible conditions, viability of using the geomagnetic field can be used as an effective propulsion source. Also by adapting the superconducting wires for the coils, the system has an advantage of low consumption of energy.
Sources: Heng-Wei Kuo, Kuo-Lang Pan, Wei-Li Lee(2021) A propellant-free superconducting solenoid thruster driven by geomagnetic field. https://doi.org/10.1016/j.jare.2020.07.014