ISRO’s PSLV Orbital Experimental Module makes atmospheric re-entry

While the higher stage of PSLV-C60 (PSLV Orbital Experimental Module or POEM-4) was in orbit, it was repeatedly tracked by ISRO’s Radar Facilities and United States Space Command (USSPACECOM) services as effectively. Photo: Special Arrangement

The higher stage (PS4) of PSLV-C60 (PSLV Orbital Experimental Module briefly POEM-4) which was launched on December 30, 2024, by ISRO re-entered the environment and impacted at 2.33 UTC (8.03 a.m. IST) on April 4, 2025, within the Indian Ocean.

On December 30, ISRO’s PSLV-C60 launched twin SPADEX satellites, and after injecting the satellites at 475 km altitude, the specifically configured higher stage (PS4) of PSLV-C60 (known as PSLV Orbital Experimental Module briefly POEM-4) was additionally nearly in the identical orbit.

“Subsequently, POEM-4 was de-orbited by engine restarts to a nearly circular orbit at 350 km altitude with 55.2 inclination. PS4 was then passivated by venting the leftover fuel to minimise any potential risk for accidental break-up. During its mission life, POEM-4 hosted altogether 24 payloads (14 payloads from ISRO and 10 from various NGEs) and all payloads worked as expected yielding valuable science data,” ISRO stated.

The area company added that whereas the POEM-4 was in orbit, it was repeatedly tracked by ISRO’s Radar Facilities and United States Space Command (USSPACECOM) services as effectively.

“The tracking data was, in turn, utilised in the re-entry prediction process. It was observed that POEM-4’s orbit had decayed to 174 km x165 km and the platform was predicted to re-enter the Earth’s atmosphere on April 4,” the area company stated.

According to ISRO, the atmospheric re-entry occasion of POEM-4 was then carefully monitored by ISRO System for Safe and Sustainable Space Operations Management (IS4OM) and common updates in predictions have been made. Finally, the POEM-4 module re-entered the environment and impacted at 2.33 UTC (8.03 IST), April 4 within the Indian Ocean.

“The safe re-entry of POEM-4 is yet another accomplishment to ISRO’s commitment to contain the growth of space debris, reaffirming the prominent role of ISRO in the long-term sustainability of the outer space environment and Debris Free Space Mission (DFSM),” the area company stated.