PSLV-C58 XPoSat: Why did ISRO launch X-Ray polarimetre satellite? What's the mission objective?

ISRO XPoSat launch: ISRO's PSLV-C58 mission placed the primary X-Ray Polarimeter satellite or XPoSat into a 650 Km Low Earth Orbit after lifting off at 9.10am.

On the first day of the New Year, the ISRO on Monday successfully launched its maiden X-Ray Polarimeter Satellite or XPoSat that would offer several insights into celestial objects like black holes. The ISRO's ever-reliable Polar Satellite Launch Vehicle (PSLV) in its C58 mission, placed the primary XPoSat into a 650 Km Low Earth Orbit as intended after lifting off at the pre-fixed time of 9.10am from the first launch pad in the Satish Dhawan Space Centre in Andhra Pradesh's Sriharikota.

ISRO's PSLV-C58 carrying an X-Ray polarimeter satellite and 10 other satellites lifts off from the spaceport of Sriharikota on January 1, 2024. (PTI)

As the 25-hour countdown concluded, the 44.4-metre tall rocket lifted off majestically with thunderous applause from spectators who had descended in large numbers at this spaceport situated about 135 km east of Chennai.

What's the objective of PSLV-C58 XPoSat mission?

• According to the ISRO, the X-ray Polarimeter Satellite or XPoSat is aimed to investigate the polarisation of intense X-ray sources in space.
• It is the first dedicated scientific satellite from the space agency to carry out research in space-based polarisation measurements of X-Ray emission from celestial sources.
• The X-Ray polarisation serves as a crucial diagnostic tool for examining the radiation mechanism and geometry of celestial sources.
• The primary payload of XPoSat is POLIX (Polarimeter Instrument in X- Rays) which is designed to measure polarimetry parameters by Raman Research Institute and XSPECT (X-ray Spectroscopy and Timing) built by the UR Rao Satellite Centre, Bengaluru. The Mission life is about five years.
• The objective is to measure the 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.

What ISRO chairman S Somanath said?

Emerging from the Mission Control Centre, ISRO chief S Somanath said, "Happy New Year to all of you. So on 1 January 2024, yet another successful mission of PSLV has been accomplished. PSLV-C58 has placed the primary satellite XPoSat in the desired orbit."

"From this point, the orbit of PSLV 4th stage will be reduced to a lower orbit where the upper stage of PSLV which is described as POEM will carry out experiments with the onboard payloads and that will take some time," he added.

"Let me also announce the orbit that has been accomplished which is available through various routes, it shows excellent orbit and the deviations from the targeted orbit is hardly just 3km in circular orbit of 650 km and inclination is 001 degree which is one of the very excellent orbital condition and yet another announcement is that the solar panel of the satellite has been deployed successfully," Somanath said.

(With inputs from agencies)