Assessment and control of electromagnetic interference in CARTOSAT-1 spacecraft

The CARTOSAT-1 or IRS-P5 is the next generation satellite after IRS-1 series in Indian Remote Sensing Satellite programme. The satellite is the "state of the art technology" with two Panchromatic cameras. These cameras provide stereoscopic images due to their angle of inclination towards earth. One camera called FORE, is mounted at +26 degrees with respect to spacecraft earth viewing axis whereas the other camera AFT, is mounted at -5 degrees. Since the FORE camera looks at a location before the AFT camera, the same target area can be viewed twice at two different angles, to give rise to stereoscopic images. This paper brings out the EMC control efforts from the beginning of the project towards realization of the flight worthy satellite. It outlines the typical EMI environments encountered, the guidelines adopted by subsystem designers with reference to EMI problems in the realization of their systems, EMC considerations in the design of harness, the EMI control techniques in the intra system level and inter system level, the grounding schemes adopted in the spacecraft and the EMI tests conducted at subsystem and system level. The on-orbit performance of CARTOSAT-1 is the final testimony to the measures adopted on ground.