Source: ISRO’s ‘zero orbital debris’ milestone (The Hindu, April 12, 2024)
The Indian Space Research Organisation (ISRO) has made significant strides in space exploration with its innovative PSLV-C58/XPoSat mission. Central to this mission’s success is the groundbreaking use of the PSLV Orbital Experimental Module (POEM), a pioneering concept developed by the Vikram Sarabhai Space Centre (VSSC). Through POEM-3, ISRO has not only advanced scientific research but also addressed the critical issue of space debris management.
Key Points
- ISRO’s PSLV-C58/XPoSat mission left nearly zero debris in earth orbit.
- The last stage of the PSLV was turned into an orbital station named POEM-3.
- Instead of staying in orbit, it was made to re-enter the earth’s atmosphere.
- After launching all satellites into their orbits, the fourth stage became POEM-3.
- It was lowered from 650 km to 350 km, making it more likely to burn up in the atmosphere.
- ISRO dumped the fuel to prevent explosion and debris in orbit.
What is POEM?
Development:
- Developed by the Vikram Sarabhai Space Centre (VSSC)
- Designed as an inexpensive space platform
- Utilizes the spent fourth stage of a PSLV rocket
Functionality:
- Powered by solar panels on the fuel tank and a lithium-ion battery
- Equipped with a navigation, guidance, and control (NGC) system
- NGC system includes Sun sensors, a magnetometer, and gyroscopes
- Utilizes helium control thrusters for stabilization
Operations:
- First used in the PSLV-C53 mission in June 2022
- Conducts in-orbit scientific experiments with various payloads
- Communicates with ISRO’s NavIC satellite constellation for navigation
- Features a telecommand system for ground station communication
Previous Demonstrations:
- Initial demonstration in the PSLV C-44 mission in 2019
- Spent fourth stage moved to a higher circular orbit after satellite deployment
- Facilitated the requirements of a student payload named Kalamsat-V2
What has POEM-3 achieved?
Mission Launch:
- ISRO launched the PSLV C-58 mission from Satish Dhawan Space Centre on January 1.
Payload Deployment:
- XPoSat satellite deployed in a 650 km orbit
- POEM-3 lowered to a 350 km circular orbit
Payloads:
- Featured nine payloads from various entities
- Including VSSC, Bellatrix Aerospace Pvt Ltd, startups, and academic institutions
Operations:
- Completed 400 orbits within 25 days
- Payloads conducted experiments
- Data collected and objectives achieved by January 27, 2024
Re-entry:
- Prepared for re-entry for two months
- Re-entered earth’s atmosphere on March 21
Why is this significant?
Space Debris Issue:
- Increasing number of satellites raises space debris concerns
- Mainly found in low earth orbit (LEO)
- Poses risks to space assets due to high speeds
Orbital Extents:
- LEO extends from 100 km to 2000 km above Earth
- Includes critical satellites for various purposes
Satellite Data:
- 2,533 objects launched in 2022 according to ISRO
- 7,000 operational satellites currently orbiting Earth
How are agencies dealing with debris?
Recent Incidents:
- March 8 incident involving space debris causing damage
- More communication satellites increase risk
Debris Projection:
- Expected increase in space debris by 2030
- Potential for cascading collisions
Regulatory Measures:
- No international laws specific to LEO debris
- Most nations follow Space Debris Mitigation Guidelines 2002
- Guidelines are specified by the Inter-Agency Space Debris Coordination Committee (IADC), which the U.N. endorsed in 2007.