This study introduces a robust model-based framework designed for the verification and validation (V&V) of Attitude Determination and Control Systems (ADCSs) in nanosatellites, focusing on magnetic actuation while still being applicable to larger spacecraft platforms. By employing Model-in-the-Loop (MIL), Software-in-the-Loop (SIL), Processor-in-the-Loop (PIL), and Hardware-in-the-Loop (HIL) methodologies, this framework enables a thorough and systematic approach to testing and validation. The framework facilitates the assessment of long-term maneuvers, addressing challenges such as initial small-attitude errors and restricted 3D movements. Two specific maneuvers are evaluated: detumbling and nadir pointing, utilizing quaternions and a comprehensive suite of sensors, including six sun sensors, a three-axis magnetometer, a three-axis gyroscope, GPS, and three magnetorquers. The methodologies—MIL, SIL, PIL, and HIL—integrate the behaviors of digital sensors, analog signals, and astrodynamic perturbations. Based on an optimized SIL environment, Monte Carlo simulations were performed to optimize control gains for nadir pointing, achieving a mean pointing accuracy of 11.69° (MIL) and 18.22° (PIL), and an angular velocity norm of 0.0022 rad/s for detumbling. The HIL environment demonstrated a mean pointing accuracy of 9.96° and an angular velocity norm of 0.0024 rad/s. This comprehensive framework significantly advances the design and verification processes for nanosatellite ADCSs, enhancing the reliability and performance of nanosatellite missions.

Small satellites with academic missions in low Earth orbit (LEO) employ magnetic attitude control systems primarily due to their ease of development and low cost. These systems utilize magnetorquers to generate a magnetic moment that interacts with Earth’s magnetic field, enabling controlled rotation of the satellite around its three axes. The successful execution of these satellite missions relies heavily on rigorous magnetic testing conducted on the Attitude Determination and Control (ADC) subsystem. Hence, the design of a magnetic field simulator that enables precise testing is of utmost importance. This paper presents a comprehensive study, analysis, and verification of the construction of a magnetic testbed capable of accurately reproducing terrestrial magnetic fields in low Earth orbits. The research was conducted in four stages. Firstly, Matlab/Simulink software was employed to predict the satellite’s orbit and the corresponding Earth’s magnetic field affecting it. Secondly, the three-axis magnetic testbed was simulated using Ansys Maxwell software to validate its technical characteristics. In the third stage, based on the previous data, the testbed was assembled and integrated into a university laboratory. Finally, calibration, testing, and verification of the testbed’s results were performed while reproducing Earth’s magnetic field from the satellite’s orbit. The final outcome was a flexible testbed design with the results exhibiting a precision exceeding 99.89%. This confirms that the magnetic testbed reliably generates results during small-satellite magnetic control tests.

The paper introduces the design and simulation of the IS501NMTB magnetic test-bed, which utilizes three Helmholtz coils controlled by three independent ITECH IT6433 DC power sources and a MAG649L magnetometer. The goal is to perform in-the-loop simulations to test detumbling and nadir-pointing attitude control algorithms for the GWSAT mission, as well as to assess the capability of the IS501NMTB to characterize the magnetic dipole of small satellites using perturbation observers. A mathematical model based on RL circuits and the Biot–Savart law is employed and validated with experimental data measured in 2021 and 2024, demonstrating parameter variations over time. Additionally, closed-loop PID, adaptive PID, and MRAC control algorithms were tested for canceling Earth’s magnetic field and simulating Earth’s magnetic field at the GWSAT orbit using the IGRF-13 model. The results obtained from these simulations are analyzed and compared using error integration and control integration metrics to determine whether the use of adaptive controllers is advantageous in this application.

The Student Small Satellite (SSS) is a university project of Asia-Pacific Space Cooperation Organization (APSCO), composed by one microsatellite (SSS-1) and two 3U CubeSats (SSS-2A and SSS-2B). Regarding SSS-1 and SSS-2A satellites, the active 3-axis magnetic control strategy has been applied in the Attitude Determination and Control System (ADCS). In this paper, the necessary study for the development of a Magnetic Simulator Testbed for the SSS-1 and SSS-2A satellites was performed using one pairs of Helmholtz coils for each axis of rotation (X, Y, Z). Each pair of coil can generate a sufficiently large and stable magnetic field that simulate the Earth’s magnetic field but with a reliable level of accuracy, to perform the ADCS test on the satellites. Matlab software was used to generate the propagation of the orbit for the satellites, to calculate the Earth’s magnetic field around that orbit and simulate a pair of Helmholtz coil in each axis of rotation to reproduce the Earth’s magnetic field using the Biot-Savart Law. The results obtained for propagation of the orbit, calculation of terrestrial magnetic field and reproduction of the magnetic field through the Magnetic Simulator Testbed, were very close to the results obtained in important researches previously consulted, giving reliability to this research and allowing an analysis to determine the real physical size that Magnetic Testbed should have. The size determined, is very close to what was expected, allowing to conclude the reliability and viability of the development of the Magnetic Testbed for APSCO SSS Project.