India has been phenomenal when it came to space exploration in 2023, its end of the year and in a momentous stride in space exploration as the countdown commences for the launch of its maiden X-Ray Polarimeter Satellite (XPoSat) aboard the Polar Satellite Launch Vehicle (PSLV) on January 1, 2024.

Scheduled for a 9:10 am liftoff, the Indian Space Research Organisation (ISRO) has unveiled plans for the XPoSat mission, heralding a groundbreaking chapter in India's foray into space exploration.

At the heart of this pioneering venture lies the quest to delve into the polarisation of intense X-ray sources, an ambitious scientific pursuit poised to position India at the vanguard of space-based polarimetry.

This mission marks India's inaugural dedicated foray into polarimetry, trailing only behind NASA's precedent-setting launch of the Imaging X-ray Polarimetry Explorer (IXPE) in 2021.

XPoSat is slated to scrutinise the 50 most luminous known sources in the cosmos, encompassing a diverse array of celestial bodies such as pulsars, black hole X-ray binaries, active galactic nuclei, neutron stars, and non-thermal supernova remnants. The satellite will be stationed in a circular low Earth orbit spanning 500-700 km, poised for a mission lifespan extending over a minimum of five years.

Central to the expedition is the primary payload, POLIX (Polarimeter Instrument in X-rays), engineered to gauge the degree and angle of polarisation within the medium X`-ray energy range of 8-30 keV photons of astronomical origin. Complementing POLIX, the XSPECT (X-ray Spectroscopy and Timing) payload will furnish spectroscopic insights covering the energy spectrum of 0.8-15 keV.

Crafted through collaborative efforts between the esteemed Raman Research Institute (RRI) and the U R Rao Satellite Centre (URSC), these instruments are primed to unravel novel facets of celestial physics. By deciphering the polarisation of X-rays, scientists anticipate unlocking crucial details about the structural composition and emission mechanisms of these remote celestial entities.