The STAR250 sensor is a CMOS active pixel sensor designed for application in optical inter-satellite link beam trackers. The STAR250 is part of broader range of applications including spaceborne systems such as sun sensing and star tracking. It features 512 by 512 pixels on a 25 µm pitch, on chip Fixed Pattern Noise (FPN) correction, a programmable gain amplifier, and a 10-bit ADC.