Context:

• According to ISRO, the indigenous platform POEM-3 (PSLV Orbital Experimental Module-3) has successfully achieved all its payload objectives. POEM-3 unique and low-cost space platform has been developed using the PS4 stage of PSLV-C58 rocket.

Important Point: 

What is POEM-3 

• POEM (PSLV Orbital Experimental Module) is an experimental mission of ISRO that carries scientific experiments in orbit as an orbital platform during the fourth stage of the Polar Satellite Launch Vehicle (PSLV) launch vehicle.
• The PSLV is a four-stage rocket where the first three spent stages fall back into the ocean, and the final stage (PS4) — after launching the satellite into orbit — ends up as space junk.
• Main features of POEM
• In PSLV-C53 mission, the spent final stage will be utilised as a “stabilised platform” to perform experiments.
• “It is the first time that the PS4 stage would orbit the earth as a stabilised platform,” According to ISRO 
• POEM has a dedicated navigation guidance and control (NGC) system for stabilization, to control the orientation of any aerospace vehicle within the permitted limits. The NGC acts as the brain of the platform to stabilize it with specified accuracy.
• POEM carried six payloads, including two from Indian space start-ups, Digantara and Dhruv Space, enabled through IN-SPACe and NSIL.
• The POEM will receive its power from solar panels and Li-ion batteries mounted around the PS4 tank. It will navigate using four sun sensors, a magnetometer, gyros and NavIC.
• It also has dedicated control thrusters using helium gas storage. It is enabled with a telecommand feature.

XPoSat 

• XPoSat was launched on January 1, 2024 with the help of PSLV-C58 rocket.
• XPoSat (X-ray Polarimeter Satellite) is ISRO's first dedicated scientific satellite to conduct research in space-based polarization measurements of X-ray emission from celestial sources.
• It carries two payloads namely POLIX (Polarimeter Instrument in X-rays) and XSPECT (X-ray Spectroscopy and Timing).POLIX is realized by Raman Research Institute and XSPECT is by Space Astronomy Group of URSC.

Objective of XPoSat Mission:

• The POLIX payload measures the polarization of X-rays in the energy band 8–30keV emanating from about 50 potential cosmic sources via Thomson scattering.
• To conduct long-term spectral and temporal studies of cosmic X-ray sources in the energy band 0.8-15keV by the XSPECT payload.
• To make polarizing and spectroscopic measurements of X-ray emissions from cosmic sources by the POLIX and XSPECT payloads, respectively, in the normal energy bands.

About PSLV

• Polar Satellite Launch Vehicle (PSLV) is India's third generation launch vehicle.
• It is the first Indian launch vehicle equipped with liquid stages.
• Since its first successful launch in October 1994, PSLV continues to serve as India's reliable and versatile launch vehicle.

About ISRO

• Established: 1969
• Headquarters: Bengaluru
• Chairman: S. Somnath