In a first, ISRO successfully launches PSLV-C58/XPoSat mission on New Year Day

Sriharikota, (Andhra Prdesh): In a first, the Indian Space agency heralded 2024 with the successful first ever New year day launch, when PSLV-C58, carrying XPoSat, X-ray Polarimeter Satellite, and ten other payloads, was successfully injected into the orbit after a majestic lift off from the spaceport of Sriharikota on Monday.

The workhorse 4-stage launch vehicle of ISRO took off from the First Launch Pad at 0910 hrs.

After a 20-minute flight duration and the ignition and separation of all the four stages the 469 kg satellite was injeced into the orbit.

“PSLV-C58/XPOSAT mission was accomplished”, ISRO Chairman S.Somanath said, addressing the scientists after the successful mission.

“Happy New Year to all. Yet another PSLV mission was accomplished successfully and placed in 650 km orbit”, he said, adding, the Orbit will be lowered to

350 km by switching off and starting the fourth stage PS4 engine–which was being used as an Orbital platofrm–of the launch vehicle twice.

“We are really happy and we are having exciting times ahead’, he said.

The solar panels on board the spacecraft were deployed and the ground stations have started monitoring by taking control of it.

Mr Somanath said “The orbit accomplished for XPoSat is excellent as the deviation is just three kms. The solar panels of the satellite have been deployed.”

After orbiting the XPoSat, the rocket’s fourth stage — PS4 stage — will be lowered to 350km, about 9.6 deg orbit, by restarting it twice.

He said ISRO will use the fourth stage as an orbital platform with 10 experimental payloads loaded on it.

“We could have done the experiments at the 650km altitude. We decided to bring down the stage to a klower orbit so that we don’t create more space debris,” Somanath said.

After injection of XPOSAT, the PS4 stage is being restarted twice to reduce the orbit into 350 km circular orbit to maintain in 3-axis stabilized mode for Orbital Platform (OP) experiments.

The PSLV Orbital Experimental Module-3 (POEM-3) experiment was executed meeting the objective of 10 identified payloads, supplied by ISRO and IN-SPACe.

With a mission life of five years, XPoSat (X-ray Polarimeter Satellite) is the first dedicated scientific satellite from ISRO to carry out research in space-based polarisation measurements of X-ray emission from celestial sources.

The objectives of the mission are 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 XSPECTpayload and 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.

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, it said.

The polarimetry measurements add two more dimension 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.

UNI