XPoSat’s X-ray Polarization Mission

XPoSat’s X-ray Polarization Mission


The recent PSLV C58 mission by ISRO unveils a dual narrative in its scientific pursuits, symbolizing a shift towards both discovery-oriented research and technological advancements. This mission follows the success of Chandrayaan-3 and signals a balanced exploration into the realms of astrophysics and orbital experimentation.


GS-03 (Science and technology)

Mains Question:

Discuss the significance of ISRO’s recent PSLV C58 mission, highlighting the organization’s dual emphasis on scientific exploration and technological innovation. Analyze how this approach reflects the evolving demands and priorities of ISRO in the contemporary space exploration landscape. (250 words)

Dimensions of the Article:

  • Scientific Missions’ Renaissance
  • Orbital Testbed Innovation
  • XPoSat Mission Overview
  • XPoSat Payloads
  • Significance of XPoSat

Scientific Missions’ Renaissance:

  • ISRO’s post-Chandrayaan-3 endeavors showcase a notable inclination towards scientific missions, emphasizing a nuanced approach to space exploration.
  • The launch of the Aditya L-1 space probe to observe the sun and the XPoSat for studying polarized X-rays highlights a deliberate shift towards broadening our understanding of astrophysical phenomena.

Orbital Testbed Innovation:

  • The innovative deployment of the PSLV fourth stage as a rudimentary satellite and orbital testbed is a strategic move reflecting ISRO’s adaptability.
  • Hosting ten diverse payloads, including contributions from private entities, this unconventional approach aligns with India’s evolving landscape in space exploration.
  • By providing a platform for private players and accommodating experiments from academic institutions, ISRO fosters a collaborative ecosystem.

XPoSat Mission Overview

  • XPoSat is designed to function in a Low Earth Orbit at an altitude of approximately 650 km, featuring a low inclination of around 6 degrees.
  • The satellite is equipped with two advanced payloads, facilitating comprehensive studies of X-ray sources. These payloads focus on exploring temporal, spectral, and polarization characteristics.
  • Primary goals of XPoSat include measuring X-ray polarization within the 8-30 keV energy range. Additionally, it aims to conduct extended studies in the 0.8-15 keV band.
  • XPoSat is anticipated to remain operational for an estimated 5-year mission lifespan.
  • The satellite will primarily conduct observations during Earth’s eclipse period, optimizing operational efficiency.

XPoSat Payloads:

  • POLIX – Primary Payload: Developed by Bengaluru’s Raman Research Institute (RRI) in collaboration with ISRO. Polarimeter Instrument in X-rays (POLIX) is specialized for assessing polarization degrees and angles in medium X-ray energy ranges.
  • XSPECT – Secondary Payload: Created by ISRO’s U.R. Rao Satellite Centre (URSC). X-ray Spectroscopy and Timing (XSPECT) payload is designed to gather spectroscopic data within the 0.8-15 keV range.

Significance of XPoSat:

  • Polarization, indicative of light wave orientation, is a crucial aspect of the mission.
  • X-rays, as a form of electromagnetic radiation, can exhibit polarization.
  • Studying polarized X-rays from cosmic sources provides valuable insights into the physical conditions and processes occurring in extreme environments, such as those around black holes, neutron stars, and supernova remnants.


ISRO’s dual focus on scientific exploration and technological innovation marks a progressive trajectory for India’s space endeavors. Embracing both discovery-driven missions and experimental orbital deployments, ISRO is poised to meet the multifaceted challenges of a space era dominated by scientific curiosity and technological advancements. The PSLV C58 mission, with its scientific and technological duality, serves as a beacon of ISRO’s evolving aspirations.