Context:
ISRO successfully launched the PSLV-C56 mission, carrying Singapore’s DS-SAR satellite and six other satellites, and also conducted the fourth stage (PS4) de-orbiting experiment.
What is De-orbiting experiment?
- A technology to drag satellites to the graveyard orbit i.e. bringing dead satellites back to Earth.
- 2 systems –
- Passive (use of integrated spacecraft)
- Active (design to move satellites in the graveyard orbit)
- De-orbiting experiment result in reduced space debris and sustainable use of space.
- In case of PSLV-C56: 4th stage of the rocket would be lowered into a 300 km high orbit after placing satellites at an altitude of 536 km to mitigate the space debris problem.
Graveyard orbit is an orbit almost 200 miles farther away from Earth than the farthest active satellites. The satellites will be placed here after their end of life and stay here for hundreds of years or even longer.
What is Space Debris?
- Refers to man-made objects in Earth’s orbit that no longer serve a useful purpose.
- Examples: Defunct satellites, spent rocket stages, fragments of debris from collisions etc,
- Hazards –
- Threat for Operational Satellites
- Restrict the availability of sought-after orbital slots
- Kessler Syndrome –
- A chain reaction of collisions between artificial objects in low Earth orbit results in a rapid proliferation of space debris i.e. a Domino Effect.
- Proposed by – Donald J. Kessler (1978)
- Makes the use of near-Earth space impossible for an extended period of time.
Mitigation of Space Debris:
- ISRO’s efforts:
- System for Safe and Sustainable Operations Management (IS 4 OM) –
- Monitor objects posing collision threats
- Predict the evolution of space debris
- Mitigate the risk posed by space debris
- Centre for Space Debris Research
- Project NETRA: An early warning system in space to detect debris and other hazards.
- System for Safe and Sustainable Operations Management (IS 4 OM) –
- Global Efforts:
- Inter-Agency Space Debris Coordination Committee (IADC) – To coordinate efforts between spacefaring nations to address the issue of space debris.
- United Nations Committee on the Peaceful Uses of Outer Space(COPUOS) – Develop guidelines for the long-term sustainability of outer space activities and mitigation of space debris.
- Clean Space initiative by European Space Agency
In the context of space technology, what is “Bhuvan”, recently in the news?
[UPSC Civil Services Exam – 2010 Prelims]
- A mini satellite launched by ISRO for promoting the distance education in India
- The name given to the next Moon Impact Probe, for Chandrayaan-II
- A geoportal of ISRO with 3D imaging capabilities of India
- A space telescope developed by India
Source: The Hindu
