The LS3 from Solar MEMS is a Sun Sensor Simulator that is based on a controlled and stable light source to stimulate optical sensors. This optical ground support equipment has a beam size diameter of 25 mm and a focal length of 18 mm. It has a beam homogeneity of greater than 90 % and a light collimation of less than 10 degrees. The simulator has a light spectrum range of 450-1100 nm and supports Modbus RTU over RS-232 communication interface. It operates without touching the sensor or the platform and includes a 19-inch controller and up to 3 optical heads per unit. The simulator requires a supply voltage of  220 VAC and an input power of 75 W. It features manual mode or PC connection through a user-friendly interface and independent operation of 1, 2, or 3 optical heads on each controller. The simulator uses M6 for rod and/or tripod for optical head mounting and is designed to work under TVAC.