Which Indian satellite had a main function to perform X-ray experiments in space and send back data to earth?

Aryabhatta Indian satellite had a main function to perform X-ray experiments in space and send back data to earth. Aryabhata was built by the Indian Space Research Organization (ISRO) to conduct experiments in X-ray astronomy, aeronomics, and solar physics. The spacecraft was a 26-sided polygon 1.4 m in diameter. All faces (except the top and bottom) were covered with solar cells.