Thermal Subsystem Operational Times Analysis for Ubiquitous Small Satellites Relay in LEO

Abstract

The success of the satellite subsystems engineering depends on the optimal design, modeling, simulation, and validation of the deliverables of the conceptual and mission design objectives. This paper presents the operational times analysis of the thermal control subsystem onboard a 97-kg microsatellite in low-Earth orbit during an eclipse period. Power-storing, communication downlink and uplink, payload processing, and thermal control overpower modes were implemented for a communication mission under worst-case orbital patterns. An embedded digital temperature and lighting controller circuitry was designed and practically validated to effect a desired logic. For an average eclipse period of 34.4 mins, the operational times of the thermal subsystem at altitudes of 400 km, 500 km, and 600 km are 38.6 mins, 38.1 mins, and 37.7 mins respectively. Moreover, the thermal control subsystem simulation reveals that reducing the operational times of non-thermal control subsystems during the eclipse period by 50 % can result in an operational factor of safety of over 1.5. At least 10 dB data link transmission margin can be achieved. The reported findings show that the operational times of spacecraft subsystems overpower modes can be reconfigured in orbit to reliably sustain the operating conditions of the capability-based satellite components for ubiquitous communication.