Analysis of the KPLO magnetic cleanliness for the KMAG instrument

In space exploration, instruments measuring magnetic fields require magnetic cleanliness because it helps to distinguish the magnetic field generated by the spacecraft from the ambient field. A spacecraft has its own DC and AC magnetic fields generated by the current flow and residual moments of the spacecraft instruments. Therefore, analysis and testing are required in the development phase. The Korea Pathfinder Lunar Orbiter (KPLO) carries the KPLO Magnetometer (KMAG) instrument to observe magnetic fields on the lunar surface and the space environment around the Moon. To verify the magnetic cleanliness of the KPLO, we analyzed the magnetic field generated by it. We used the positional information and the magnetic dipole moments of twenty-five instruments, with which the KPLO is equipped. The analysis method was a Python program using magpylib. Finally, the worst-case analysis results showed that the spacecraft field around the magnetometer is less than 700 nT, which is the KMAG magnetic cleanliness requirement.