XPoSat Mission – ISRO Opens Data & Guest Observer Opportunity

IN NEWS: XPoSat Mission – ISRO Opens Data & Guest Observer Opportunity

Introduction

The Indian Space Research Organisation (ISRO) organised a National Meet on XPoSat Mission on 13 October 2025, where it released scientific data and announced an Opportunity for Guest Observers for Indian scientists. The mission represents India’s first dedicated space-based X-ray polarimetry observatory.

About XPoSat Mission

• Full Form: X-ray Polarimeter Satellite (XPoSat)
• Launch Date: 1 January 2024
• Launch Vehicle: PSLV-C58
• Launch Site: Satish Dhawan Space Centre
• Orbit:
  • Low Earth Orbit (LEO)
  • ~650 km altitude
  • ~6° inclination (near-equatorial orbit)
• Mission Life: 5 years
• Nature of Mission:
  • Proposal-driven X-ray astronomy observatory
  • Similar model as AstroSat

Scientific Objectives

• Study polarisation of X-ray emissions from celestial objects
• Observe black holes, neutron stars, and cosmic X-ray sources
• Conduct:
  • Spectral analysis
  • Timing studies
  • Polarisation measurements
• Covers ~50 cosmic X-ray sources

Scientific Payloads

1. POLIX (Polarimeter Instrument in X-rays)

• Energy Range: 8–30 keV
• Function:
  • Measures degree and angle of X-ray polarisation
• Developed by:
  • Raman Research Institute

2. XSPECT (X-ray Spectroscopy and Timing)

• Energy Range: 0.8–15 keV
• Function:
  • Provides spectroscopic and timing data
• Developed by:
  • U R Rao Satellite Centre

Key Technological Significance

• First Indian mission to combine:
  • Timing
  • Spectroscopy
  • Polarisation
    → on a single observation platform
• Enhances:
  • Astronomical research capability
  • Space instrumentation expertise
  • Scientific data ecosystem in India

Data Release & Scientific Access

• First dataset released:
  • ~143 GB scientific data
• Access through:
  • Indian Space Science Data Centre
• Additional tools:
  • XPPS (XPoSat Proposal Processing System)
  • XPoViewer (Target visibility analysis tool)

Announcement of Opportunity (AO)

• ISRO opened Guest Observer Programmefor:
  • Indian scientists
  • Researchers from universities, colleges, institutions
• Features:
  • Proposal-based access to satellite observation time
  • 60% observation time reserved for Indian researchers (initial cycle)
  • Observations planned till December 2026

Proposal & Selection Process

• Proposals submitted via XPPS portal (ISSDC)
• Deadline: 30 November 2025
• Selection by:
  • XPoSat Time Allocation Committee (XTAC)
• Criteria:
  • Scientific merit
  • Technical feasibility

Data Policy

• Selected researchers get:
  • 6-month proprietary access to data
• After that:
  • Data becomes publicly available in ISSDC archive
• Researchers must:
  • Publish results in peer-reviewed journals
  • Acknowledge XPoSat data usage

National Meet Highlights

• Organised at ISRO Headquarters, Bengaluru
• Participation:
  • ~175 participants
  • ~50 from academia
  • ~15 institutions represented
• Key dignitaries:
  • V Narayanan
  • A S Kiran Kumar
  • Tirtha Pratim Das

Additional PSLV Experiment (POEM-3)

• PSLV-C58 also carried:
  • 10 additional payloads under POEM-3 (PSLV Orbital Experimental Module)
• Included:
  • Radiation Shielding Module
  • Women Engineered Satellite
  • BeliefSat (Amateur radio satellite)
  • Green Impulse Transmitter
  • LEATTD (Technology demonstrator)

Significance

• Strengthens India’s position in high-energy astrophysics
• Encourages:
  • Academic participation
  • Research collaboration
• Builds foundation for:
  • Future advanced space observatories

Static Part (For Exam)

Conclusion (One-Line)

XPoSat marks India’s entry into advanced X-ray polarimetry, combining multiple observational techniques and opening scientific access to the national research community.