March 07, 2025

The fourth edition of the PSLV Orbital platform Experiment Module (POEM-4), the repurposed spent upper stage of the PSLV vehicle used for PSLV-C60/ SPADEX Mission, has successfully completed 1000 orbits on March 04, 2025. The PSLV-C60 Mission was launched on December 30, 2024 and POEM-4 began its operations subsequent to the successful injection of the SPADEX spacecraft. POEM-4 was configured as a three-axis stabilized platform that carried 24 payloads including 10 payloads from Non-Governmental Entities (NGEs) and 14 payloads from ISRO/DoS. All the payloads including those from NGEs have successfully completed the intended experiments in orbit.

POEM-4 carried out experiments in space robotics, germination of seeds & growth of bacterium in microgravity, green propulsion, laser ignition of pyro thrusters, amateur radio transmission and advanced sensors. The up-linking & execution of an AI model as part of AI lab in space was also tested by a space start-up.

The POEM-4 avionics system also validated a Mission Management Computer based on a “Made-in-India” 32-bit processor, Vikram3201, with a custom architecture developed by ISRO along with the use of a Nano star sensor for the first time to aid the navigation system. The platform also employed a stabilization system based on reaction wheels for attitude control along with cold gas thrusters that extended the orbital life of the module by at least 45 days compared to previous POEM missions.

POEM-4 carried the maximum number of payloads till date compared to the previous three POEM missions and has yet again proved its versatility as a cost-effective experimental platform to support diverse payloads.