Star Tracker-based Attitude Determination System (STADS)

Technical Project - IIT Bombay Student Satellite Program

Designation: Electrical and Systems Engineer
Duration: January 2020 - October 2021

CubeSats are becoming increasingly popular for space-based applications, and a significant portion of them need accurate attitude (orientation wrt some given frame) determination and control for their designated function. Among the various sensors available today, star trackers, by far, offer the best accuracy. This mission aims at designing an indigenous star tracker and testing it onboard the orbital platform provided by ISRO on the Stage 4 of the PSLV.

Star trackers use a camera to take images of the sky, which are then processed to find centroids of the stars in the image. The relative locations of these centroids in the image plane are then used to identify the stars in the image with the help of a pre-loaded star catalogue. Direction vectors computed using the centroids and the star identities are used to determine the attitude of the satellite.

My work as an electrical engineer inolved reviewing, designing and implementing a centroid extraction algorithm, ensuring that it could be run on the FPGA we had selected to go on the Star Tracker. As systems engineer, I took technical and administrative decisions to ensure that the team was on track to complete the mission at hand. I also helped write the Quality Assirance guidelines that were to be followed by the team in order to guarantee repeatability and reliability.