Abstract
The Space Robotics Laboratory (SRL) of Tohoku University and ALE Co., Ltd. have developed a 60-kg-class microsatellite ALE-1, which generates artificial meteors by releasing meteor source pellets towards the Earth. The purpose of this research is to establish a system for ground evaluation and operation training of ALE-1. This satellite requires an accurate orbit and attitude determination technique for operation safety and mission success. A triple redundant system with multiple independent sensors is adopted for ensuring safe operation. A generic ground evaluation system “MEVIμS” is applied to evaluate such a complicated satellite bus system. MEVIμS has a high reliability and flexibility based on the results of its application to past micro-satellite projects. This system contains a satellite simulator with a space dynamics calculator with a high accuracy as well as mathematical models of the space environment and satellite components. A hardware-in-the-loop simulation can be carried out to evaluate the satellite hardware with on-board software by connecting to the simulator virtually. The performance evaluation of the attitude control system and comprehensive mission operational tests were carried out by MEVIμS. The simulation result demonstrated that ALE-1 reached a sufficient level of attitude control accuracy to realize the mission. The result also confirmed that the mission sequence was performed successfully as the mission feasibility and the operation safety were validated. ALE-1 was launched by the fourth Epsilon rocket on January 18, 2019 and initial operation is in progress. Further improvement of the ALE-1 system can be executed by repeated operation training under various conditions to enhance the chance of mission success.
