ISRO kicks off New Year with XPoSat launch success, India's 1st X-ray Polarimeter satellite

Sriharikota: The Indian Space Research Organisation (ISRO) commenced the new year of 2024 with the successful launch of the X-ray Polarimeter Satellite (XPoSat) today, January 1, 2024. Using the Polar Satellite Launch Vehicle-C58 (PSLV), the launch occurred around 9:10 am from the first launch pad in Sriharikota, Andhra Pradesh with the intent to place the satellite into an Eastward low inclination orbit.

The achievement has also positioned India as the second country to conduct studies on black holes. After the 25-hour countdown concluded, the 44.4-meter rocket soared into the sky amidst cheers from the gathered spectators at the spaceport, located approximately 135 kilometers east of Chennai.

Primary Payload aboard XPoSat and their purpose 

The XPoSat consists of two primary payloads – POLIX and XSPECT, each with its specific goals. The first payload, POLIX, was developed by the Raman Research Institute and UR Rao Satellite Centre. Meanwhile, the second one, XSPECT (X-ray SPECtroscopy and Timing), will aid scientists in gathering 'soft X-rays' with high accuracy in spectroscopic details. The mission has a life duration of five years.

Preceding the launch, ISRO had stated that this mission is "India's first dedicated polarimetry mission to study various dynamics of bright astronomical X-ray sources in extreme conditions." These sources, such as black holes, neutron stars, and pulsar wind nebulae, exhibit complex processes that are challenging to comprehend. Also ISRO had added in its statement that , ”The PSLV Orbital Experimental Module-3 (POEM-3) experiment will be executed meeting the objective of 10 identified payloads, supplied by ISRO and IN-SPACe.”

Main objectives ISRO aims to attain from the XPoSat launch

• Measure polarisation of X-rays ranging from 8-30keV emitted by approximately 50 potential cosmic sources using Thomson Scattering via the POLIX payload.
• Conduct prolonged spectral and temporal studies of cosmic X-ray sources within the energy band of 0.8-15keV through the XSPECT payload.
• Perform polarisation and spectroscopic measurements of X-ray emissions from cosmic sources using the POLIX and XSPECT payloads, respectively, within a shared energy band.

ISRO scientists on the XPoSat launch

According to prior statements from ISRO scientists, the goal of this mission is not only India-centric but also for the greater benefit of the global Astronomy community.

G Madhavan Nair, former ISRO Chairman, expressed confidence in the PSLV-C58/XPoSat launch, highlighting the PSLV’s impressive track record. This launch on the first day of the new year marks the PSLV's 60th mission and has achieved a success rate of more than 95 percent in all launches.

Further, Nair spoke about the significance of the launch, stating, “This launch is a significant scientific mission that will provide an observation system for studying the fundamental phenomena associated with galaxies, black holes, dying stars... It will shed light on the origin of the universe... Spare capacity is being utilized to carry several small satellites, including student satellites from various universities. On this occasion, I wish ISRO a great year with the launch of the Polar SAT launch vehicle (PSLV) on January 1, 2024…”

XPoSat launch after the stellar year

This mission marks a significant step in developing expertise in X-ray polarimetry in India, laying the groundwork for future advancements and encouraging collaboration within the astronomy community, reports added.

This launch follows ISRO’s stellar year with triumphs of Chandrayaan-3, making India the first country to land near the lunar south pole, followed by the launch of Aditya L1, India’s first solar mission to study the Sun’s chromosphere and corona. It is set to reach the Lagrange point (L1) in the Earth-Sun system on January 6.