Why in news? The Indian Space Research Organisation (ISRO) for the first time used the fourth stage of its Polar Satellite Launch Vehicle as an orbital platform with deployed solar panels to carry out experiments using seven Indian payloads embedded in it.

About PSLV Orbital Experimental Module-2 (POEM-2):

• Normally, the fourth stage of a rocket becomes a part of space debris orbiting the earth, or falls down to earth as junk, after releasing the satellites in their space orbits.
• But ISRO’s experiment, is a game-changer: it uses the fourth stage to orbit with the embedded payloads within to allow ground-based space scientists to control the experiments on them through commands from the ground stations.
• It will happen even as the solar panels on the fourth stage, deployed facing the sun, keep powering it throughout its orbits around the earth. This part of the mission is called PSLV Orbital Experimental Module-2 (POEM-2).
• It was initiated after the PSLV-C55 launcher released two Singaporean satellites — TeLEOS-2, the primary satellite, and Lumelite-4, as a co-passenger — in their respective space orbits as part of a commercial launch by ISRO’s commercial arm, New Space India Ltd.
• This was the third big launch of the year for the Indian space agency, which is in the midst of prepping for bigger missions going forward including the Chandrayaan-3 and the maiden solar mission, Aditya L-1.
• The four embedded, or non-separating, payloads on board PSLV-C55’s fourth stage belong to ISRO, Bellatrix, Dhruva Space and the Indian Institute of Astrophysics (IIA).
• The embedded payloads included PiLOT (PSLV In orbitaL Obc and Thermals) and ARIS-2 (Advanced Retarding potential analyser for Ionospheric Studies) experiment from ISRO’s Indian Institute of Space Science and Technology (IIST), Thiruvananthapuram; HET-based ARKA200 Electric Propulsion System from Bellatrix; DSOD-3U and DSOD-6U deployer units along with DSOL-Transceiver in S- & X- bands from Dhruva Space and Starberry Sense Payload from IIA.

TeLEOS-2 satellite

• The 741 Kg TeLEOS-2 satellite is developed under a partnership between DSTA (representing the Government of Singapore) and ST Engineering.
• Once deployed and operational, it will be used to support the satellite imagery requirements of various agencies within the Government of Singapore.
• TeLEOS-2 will provide all-weather day and night coverage, and be capable of imaging at 1m full-polarimetric resolution.

Lumelite-4 satellite

• The 16 Kg Lumelite-4 satellite is co-developed by the Institute for Infocomm Research (I2R) of A*STAR and Satellite Technology and Research Centre (STAR) of the National University of Singapore.
• It is an advanced satellite developed for technological demonstration of the High-Performance Space-borne VHF Data Exchange System (VDES). Using the VDES communication payload developed by I2R and STAR’s scalable satellite bus platform, it aims to augment Singapore’s e-navigation maritime safety and benefit the global shipping community.