XPoSat

XPoSat (X-ray Polarimeter Satellite) is India's first dedicated X-ray polarimetry mission and the world's second operational X-ray polarimetry observatory, after NASA's IXPE (launched December 2021). The satellite studies X-ray polarisation from around 50 bright cosmic sources including pulsars, black holes, magnetars, and supernova remnants.

The POEM-3 non-deployable platform on the fourth stage hosted nine experimental payloads, six of which were provided by non-governmental entities through ISRO's IN-SPACe programme.