Context: A new low-cost star sensor, developed by astronomers from the Indian Institute of Astrophysics (IIA) from off-the-shelf components, was recently put into space by ISRO’s PSLV C-55.
About the Star sensor:
- Named ‘StarBerrySense’, the payload (sensor) is mounted on ISRO’s PSLV orbital experimental module (POEM), which provides a stable platform for our payload to operate from.
- POEM is a unique initiative by ISRO that utilises the spent fourth stage of the PSLV rocket as an orbital platform for carrying out scientific experiments.
- Main function of StarBerrySense is to image the field of view, correctly identify the stars it sees, and accurately calculate where a satellite is pointing in space, as for any space mission it is crucial to know the exact positioning of the satellite. The start sensor is capable of finding its pointing direction in space by identifying the stars in its field of view.
- This payload is built around the well-known minicomputer RaspberryPi, and the electronics and software were designed in-house. The advantage of this payload is that it is cost-effective, simple to build, and can be deployed on a wide variety of satellites.
Star-sensor:
- The star sensor is essentially a celestial compass. Any satellite needs to know where it is pointed in space, and the instrument used for this purpose is called a star sensor.
- The position of stars in the sky is fixed relative to each other and can be used as a stable reference frame to calculate the orientation of a satellite in orbit. This is done by correctly identifying the stars in the sky towards which the star sensor is pointed.
