Thermal subsystem aims at maintaining the individual components within their temperature limits to ensure proper functioning and also the overall internal temperature between 0-40 0C which satisfies the temperature requirements of all the subsystems. For this various thermal control measures are being employed (completely passive): Multilayer Insulation (MLI), Thermal Vias, Heat Sinks, paints, radiators, fillers and sensors are being employed for housekeeping. The thermal design and analysis are being carried out numerically using the software NX 7.5 (Space Systems Thermal Module). Multilayer insulation is used to shield the whole structure from the external solar. Thermal Vias and Heat Sinks for the PCB have been designed to help dissipate heat out of the electronic devices from the bottom. Thermal Protective Paints are paints having special radiative properties. Black paint and white paints will be applied at appropriate. Thermistors are being used for temperature monitoring. Sensor data sent to OBC for housekeeping. Fillers are being used to increase the conductive heat transfer between contacting surfaces (joints).