Design and On-Orbit Performance of the Attitude Determination and Passive Control System for the Quetzal-1 CubeSat

This article describes the design and on-orbit performance of the internally developed passive attitude determination and control system (ADCS) for Guatemala's first satellite, Quetzal-1. The 1U CubeSat employed a passive magnetic control strategy based on a 0.74 A·m² permanent magnet and two orthogonal hysteresis rods for stabilization. One week after deployment from the International Space Station, the system successfully reduced rotation rates from ±25°/s to ±3.5°/s per axis and aligned the satellite to within 14.28° of Earth's magnetic field. The study also analyzes the performance of onboard sensors, photodiode degradation, and the effects of the South Atlantic Anomaly on magnetic torque and pointing accuracy. The results offer practical recommendations for teams seeking to implement low-cost passive attitude control systems in small satellites.