MEMS based Sun sensor

Sun sensors have been widely used as a part of spacecraft attitude determination subsystems to provide a measurement of the Sun vector in spacecraft coordinates. An experimental MEMS based Sun sensor is presented. This prototype sun sensor is comprised of a silicon wafer mask with several hundred small apertures placed on top of a CCD focal plane array at a distance of 750 /spl mu/m. An image of the apertures is formed on the focal plane when the sun illuminates this setup. Sun angles can be derived by analyzing the image. The experimental data presented indicates that this sun sensor can achieve accuracies on the order of a few arcminutes or better. It is projected that this type of sun sensor, utilizing an active pixel sensor focal plane array, will be the size of three dimes stacked on top of each other. It will have a mass of less than 30 g and consume less than 20 mW. This will make this type of sun sensor ideal for micro/nano spacecraft and small rovers.