ISRO Launches XPoSat Today: India's Historic Mission To Study Black Holes

ISRO on Monday launched its first X-Ray Polarimeter Satellite which will offer insights into celestial objects like black holes, onboard a Polar Satellite Launch Vehicle rocket.

The XPoSat mission lifted off at 9:10 am from the first launch pad at the Satish Dhawan Space Centre in Sriharikota.

XPoSat, India's first polarimetry mission, will explore the diverse dynamics exhibited by bright astronomical X-ray sources under extreme conditions. Positioned in a low Earth orbit, the spacecraft will be equipped with two scientific payloads.

The primary instrument, POLIX (Polarimeter Instrument in X-rays), is dedicated to measuring polarimetry specifically, the degree and angle of polarization-in the medium X-ray energy range of 8-30 keV for photons originating from astronomical sources. Additionally, the XSPECT (X-ray Spectroscopy and Timing) payload will provide valuable spectroscopic information within the energy range of 0.8-15 keV, according to a statement from the space organisation.

"The emission mechanism from various astronomical sources such as blackhole, neutron stars, active galactic nuclei, pulsar wind nebulae etc. originates from complex physical processes and are challenging to understand. While the spectroscopic and timing information by various space based observatories provide a wealth of information, the exact nature of the emission from such sources still poses deeper challenges to astronomers.

The polarimetry measurements add two more dimensions to our understanding, the degree of polarization and the angle of polarization and thus is an excellent diagnostic tool to understand the emission processes from astronomical sources. The polarimetric observations along with spectroscopic measurements are expected to break the degeneracy of various theoretical models of astronomical emission processes. This would be the major direction of research from XPoSat by Indian science community," the statement added.

The rocket for the launch is the PSLV-DL variant, boasting a lift-off mass of 260 tonnes. The fourth stage is configured as a 3-axis stabilized orbital platform designed for the execution of experiments.

The diverse array of payloads includes the Radiation Shielding Experiment Module by TakeMe2Space, the Women Engineered Satellite by LBS Institute of Technology for Women, BeliefSat (an amateur radio satellite) constructed by K J Somaiya Institute of Technology, the Green Impulse Transmitter by Inspecity Space Labs Pvt Ltd, the LEATTD (Launching Expeditions for Aspiring Technologies Technology Demonstrator) by Dhruva Space Pvt Ltd, RUDRA 0.3HPGP and ARKA 200 developed by Bellatrix Aerospace Pvt Ltd, the Dust Experiment (DEX) crafted by PRL, ISRO, and the Fuel Cell Power System and Si-based High Energy cell built by Vikram Sarabhai Space Centre.

The Indian space organisation had conducted a similar scientific experiment using POEM-2 in the PSLV-C55 mission in April 2023.

Apart from the ISRO, the National Aeronautics and Space Administration (NASA) in the United States undertook a similar study. Specifically, NASA conducted the Imaging X-Ray Polarimetry Explorer mission in December 2021, focusing on the remnants of supernova explosions, particle streams emitted by black holes, and various other cosmic events.