PSLV Orbital Experimental Module (POEM)
- Posted By
Science & Technology
2nd Jul, 2022
ISRO has recently launched three Singaporean satellites in precise orbit through the PSLV Orbital Experimental Module or ‘POEM’.
What is POEM?
- The PSLV Orbital Experimental Module is a platform that aims to help perform in-orbit experiments using the final, and otherwise discarded, stage of ISRO’s workhorse rocket, the Polar Satellite Launch Vehicle (PSLV).
- 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.
- However, in PSLV-C53 mission, the spent final stage has been utilised as a “stabilised platform” to perform experiments.
- POEM is carrying six payloads, including two from Indian space start-ups Digantara and Dhruva Space.
- POEM has a dedicated Navigation Guidance and Control (NGC) system for attitude stabilisation, which stands for controlling the orientation of any aerospace vehicle within permitted limits.
- The NGC will act as the platform’s brain to stabilize it with specified accuracy.
- POEM will derive its power from solar panels mounted around the PS4 tank, and a Li-Ion battery.
- It will navigate using “four sun sensors, a magnetometer, gyros & NavIC”.
- It carries dedicated control thrusters using Helium gas storage.
- It is enabled with a tele-command feature.
Has ISRO repurposed and used PS4 rocket junk earlier?
- The Indian space agency first demonstrated the capability of using PS4 as an orbital platform in 2019 with the PSLV-C44 mission.
- In that mission, they injected Microsat-R and Kalamsat-V2 satellites into their designated orbits.
- The fourth stage in that mission was kept alive as an orbital platform for space-based experiments.
- The fourth stage (PS4) of the vehicle was moved to a higher circular orbit of 453 km after two restarts of the stage, to establish an orbital platform for carrying out experiments.
- Kalamsat-V2, a student payload, first to use PS4 as an orbital platform, was taken to its designated orbit about 1 hour and 40 minutes after lift-off.
- While in that mission, the fourth stage had Li-Ion batteries, solar panels are an addition this time.
- The latest repurposing and upgrade of the fourth stage of the PSLV rocket involves stabilization of the orbital platform.