ISRO Rockets Into New Year With Successful Launch Of XPoSat

With XPoSat, the ISRO successfully launched its first mission of 2024 on the very first day of the new year.

New Delhi: Today, the Indian Space Research Organisation (ISRO) achieved a successful launch of the nation's inaugural polarimetry mission, XPoSat. This mission is designed to explore the diverse dynamics of intense astronomical X-ray sources under extreme conditions. ISRO executed the launch of the X-ray Polarimeter Satellite (XPoSat) from the Sriharikota spaceport on Monday at the planned time of 9:10 am. The XPoSat was effectively placed into its designated orbit, positioned 650 km above the Earth's surface6-degree inclination.

PSLV-C58/XPoSat Mission:
Lift-off normal 

XPoSat satellite is launched successfully.

PSLV-C58 vehicle placed the satellite precisely into the intended orbit of 650 km with 6-degree inclination.

The POEM-3 is being scripted ...#XPoSat

— ISRO (@isro) January 1, 2024

According to ISRO The XPOSAT satellite has two payloads:

POLIX: This will measure the polarimetry parameters (degree and angle of polarization) in medium X-ray energy range of 8-30 keV photons of astronomical origin. The payload is being developed by Ramam Research Institute (RRI), Bangalore in collaboration with U R Rao Satellite Centre (URSC). The instrument is made of a collimator, a scatterer and four X-ray proportional counter detectors that surrounds the scatterer. The scatterer is made of low atomic mass material which causes anisotropic Thomson scattering of incoming polarised X-rays. The collimator restricts the field of view to 3 degree x 3 degree so as to have only one bright source in the field of view for most observations. POLIX is expected to observer about 40 bright astronomical sources of different categories during the planned lifetime of XPoSat mission of about 5 years. This is the first payload in the medium X-ray energy band dedicated for polarimetry measurements.

XSPECT: Will give spectroscopic information in the energy range of 0.8-15 keV. An X-ray SPECtroscopy and Timing payload onboard XPoSat, which can provide fast timing and good spectroscopic resolution in soft X-rays. Taking advantage of the long duration observations required by POLIX to measure X-ray polarization, XSPECT can provide long-term monitoring of spectral state changes in continuum emission, changes in their line flux and profile, simultaneous long term temporal monitoring of soft X-ray emission in the X-ray energy range 0.8-15 keV. An array of Swept Charge Devices (SCDs) provide an effective area >30 cm2 at 6 keV with energy resolution better than 200 eV at 6 keV. Passive collimators are used to reduce the background by narrowing the field of view of XSPECT. XSPECT would observe several types of sources viz X-ray pulsars, blackhole binaries, low-magnetic field neutron star (NS) in LMXBs, AGNs and Magnetars.

2024 lifted off majestically. 

XPoSat health is normal.
Power generation has commenced. pic.twitter.com/v9ut0hh2ib — ISRO (@isro) January 1, 2024

The objective of the mission is to measure polarisation of X-rays in the energy band 8-30keV emanating from about 50 potential cosmic sources through Thomson Scattering by POLIX payload. To carry out long term spectral and temporal studies of cosmic X-ray sources in the energy band 0.8-15keV by XSPECT payload. To carry out polarisation and spectroscopic measurements of X-ray emissions from cosmic sources by POLIX and XSPECT payloads respectively in the common energy band.

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. The exact nature of the emission from such sources still poses deeper challenges to astronomers. The polarimetry measurements add two more dimension to understanding, the degree of polarization and the angle of polarization and thus is a diagnostic tool to understand the emission processes from astronomical sources.

In a stellar display of prowess, India soared to new heights in 2023 with the successful soft landing of Chandrayaan-3 on the south pole of moon and the launch of Aditya-L1, India's first solar mission.