A propellant-free superconducting solenoid thruster driven by geomagnetic field*

We computed the force exerted on a solenoid in a magnetic field, and compared with the experimental results to verify the effect of magnetic moment gradient on exerted force. Based on the concept, a superconducting solenoid thruster driven by geomagnetic field is devised, which has advantages of low energy consumption and propellant-free. To further enhance the force exerted on the solenoid, we replaced an aluminum core with an iron core. Moreover, we placed the solenoid in the geomagnetic field and measured the forces corresponding to different gradients due to variation of cross-sectional area and electric current magnitude. The results demonstrated a proportionality between the force and these two factors, as predicted by the theory. By measuring and calculating the force exerted on a superconducting solenoid at low temperature, we can simulate the condition when such a thruster is used in space. The results showed that the force exerted on a superconducting solenoid at low temperature matched the predicted force relation versus the gradient of varying cross-sectional area and electric current magnitude at room temperature. Therefore, the relation can provide a reference for design of an alternative thruster for space exploration.