XPoSat (X-ray Polarimeter Satellite) is India’s first dedicated polarimetry mission to study various dynamics of bright astronomical X-ray sources in extreme conditions. The spacecraft will carry two scientific payloads in a low earth orbit. The primary payload POLIX (Polarimeter Instrument in X-rays) will measure the polarimetry parameters (degree and angle of polarization) in medium X-ray energy range of 8-30 keV photons of astronomical origin. The XSPECT (X-ray Spectroscopy and Timing) payload will give spectroscopic information in the energy range of 0.8-15 keV.

Two payloads of XPoSat are hosted on a modified IMS-2 satellite bus. Primary scientific payload is Polarimeter Instrument in X-rays (POLIX), which will study the degree and angle of polarisation of bright astronomical X-ray sources in the energy range 8-30 keV. POLIX, a 125 kg (276 lb) instrument, is being developed by the Raman Research Institute. Secondary payload is XSPECT (X-ray Spectroscopy and Timing), which will give spectroscopic information of soft X-rays in the energy range of 0.8-15 keV.

10 attached payloads on the PSLV 4th stage will perform various experiments and testing from Indian institutions coordinated by ISRO.