ISRO’s XPoSat prepared for launch: Groundbreaking x-ray polarimeter satellite ready for D-day

The Indian Space Research Organisation (ISRO) is set to launch the X-ray Polarimeter Satellite (XPoSat) on January 1, marking a significant step in understanding the mysteries of the universe. This mission, India’s first dedicated polarimeter, seeks to investigate the complex behavior of bright astronomical X-ray sources found in extreme environments.

Rising at 9:10 a.m., XPoSat will propel the Polar Satellite Launch Vehicle (PSLV) into low Earth orbit. This mission includes two state-of-the-art payloads and promises groundbreaking revelations that will further our understanding of the vast astronomical universe.

The primary payload, POLIX (polarimeter Instrument in X-rays), is designed to measure polarimetry parameters, including polarization degree and angle, in the medium X-ray energy range. This is complemented by another payload, XSPECT (X-ray Spectroscopy and Timing), providing crucial spectroscopic information.

The importance of this mission lies in its potential to provide transformative insights into the enigmatic emission mechanisms of celestial bodies such as black holes, neutron stars, active galactic nuclei and pulsar wind nebulae. These phenomena, based on complex physical processes, have long puzzled scientists, despite valuable information obtained from existing space observatories.

India’s XPoSat mission aims to capture the elusive degree and angle of polarization, introducing two key elements to unraveling these celestial puzzles. “Polarimetric observations and spectroscopic measurements are expected to break the degeneracy of various theoretical models of astronomical emission processes. This would be the main thrust of XPoSat research by the Indian scientific community,” ISRO said of the mission.

XPoSat mission objectives

1. Measurement of X-ray polarization in the 8-30 keV energy band from X-ray sources.

2. Long-term spectral and temporal studies of cosmic X-ray sources in the 0.8-15 keV energy band.

The estimated duration of the mission is about five years, and the XPoSat payloads will diligently observe X-ray sources as they pass through the Earth’s shadow, especially during the eclipse period.

XPoSat Payloads:

POLIX: An X-ray polarimeter developed for astronomical observations in the 8-30 keV energy range. This pioneering payload is a collaboration between Bengaluru-based Raman Research Institute (RRI) and U R Rao Satellite Center (URSC). It marks the first payload in the intermediate X-ray energy band dedicated to polarimetry measurements.

XSPECT: X-ray spectroscopy and timing payload on XPoSat designed to provide fast timing and excellent spectroscopic resolution in soft X-rays.

As India takes this important step into the celestial unknown, XPoSat is poised to unravel the complexities of the cosmos and provide a new frontier for scientific exploration and discovery.