India’s POEM-4 Experiment Module Crashes Into Ocean After Successful Orbital Mission

The used fourth stage of the Indian rocket Polar Satellite Launch Vehicle-C60 (PSLV-C60) used to carry out experiments in orbit called PS4-Orbital Experiment Module (POEM-4), safely crashed in the Indian Ocean, said the Indian space agency.

India’s PSLV-POEM Mission Ends with Controlled Splashdown

According to ISRO, the four-stage PSLV rocket launched on 30 December 2024 had twin SPADEX satellites as its primary passengers.

The main aim of the mission was to dock and undock in space the twin satellites SDX01 and SDX02 – for India’s future space missions.

ISRO has been using the PSLV’s spent fourth stage as an experimental module – PS4-Orbital Experimental Module (POEM) to carry out experiments and test new instruments while in orbit.

The idea is to provide an opportunity for the scientific community to carry out certain in-orbit microgravity experiments for an extended duration of up to three months using the POEM platform, which otherwise would end up as space debris immediately after orbiting the primary payload.

Such experimental payloads serve as precursor experiments to validate various proof-of-concept and enabling technologies for future missions, said ISRO.

ISRO Proves Space Docking Tech with the SpaDex satellites

On 30 December 2024, PSLV-C60 launched twin SpaDex satellites, and after injecting satellites at 475 km altitude, the specially configured upper stage (PS4) of PSLV-C60 (called PSLV Orbital Experimental Module in short POEM-4) was also almost in the same orbit.

Later, POEM-4 was de-orbited by engine restarts to a nearly circular orbit at 350 km altitude with 55.2 degree inclination. According to ISRO, all the 24 payloads on POEM worked as expected and yielded useful scientific data.

Subsequently, the PS4-POEM was passivated by venting the leftover fuel to minimise any potential risk for accidental break-up.

ISRO then monitored the atmospheric re-entry of POEM-4. Regular updates and predictions were made by ISRO System for Safe and Sustainable Space Operations Management.

Finally, the POEM-4 module re-entered the atmosphere and impacted at 02:33 UTC (08:03 IST), 4 April 2025, in 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 outer space environment and Debris Free Space Mission (DFSM),” the Indian space agency said.

In January this year, India became the fourth country in the world to successfully dock two satellites in space and took the first step towards setting up its own space station –Bharatiya Antriksh Station (BAS-expected to be in 2035), bringing samples from the moon and others.

And in March, the undocking of the two satellites was carried out.

The technology of mating satellites and other objects in space is essential when multiple rocket launches are required to achieve common mission objectives and also for sending people and cargo to space stations.

The mission life will be up to two years.