The Magnetometer Boom Instrument aims at measuring the magnetic field at the first Sun-Earth Lagrangian point (L1). It will be flown on-board a space solar observatory which will orbit around L1 point. The magnetic field measurements at the L1 point aim at the detection of solar plasma waves and to measure the low intensity vector magnetic field occurring due to dynamic solar activity. This will lead to a better understanding of the magnetic storms which pose a hazard to orbiting satellites, telecommunication facilities, electric power grid and air traffic on polar routes.

To deliver specified functional performance, the instrument must be maintained in the specified temperature range - hence the need for Thermal Control System (TCS). A completely passive TCS is evolved to ensure magnetic cleanliness in the proximity of the sensor, thereby prohibiting use of electric heaters and sensors. Thermal design makes use of optically selective surfaces and conductive isolations from boom. Thermal constraints are identified in terms of instrument orientation with respect to the sun.

This paper highlights the TCS designed for this type of instrument, by considering various parameters.