Science and technology ยท GS3
Space debris and large satellite constellations
One line
ISRO highlighted the debris risk created by proliferating large low-Earth-orbit satellite constellations and India's mitigation efforts.
Summary
More satellites improve connectivity and observation but increase conjunctions, collision risk, radio interference, and re-entry concerns. Space sustainability is a shared international problem because debris crosses borders.
PYQ pattern
UPSC can connect space debris with common resources, international law, private constellations, and strategic space-domain awareness.
Core notes
- Space debris includes defunct spacecraft, spent stages, and fragments.
- A collision can create many fragments and raise future collision probability.
- Mitigation includes passivation, collision avoidance, post-mission disposal, and design for demise.
- Space situational awareness tracks objects and predicts close approaches.
Prelims lens
- Low Earth orbit lies below geostationary orbit.
- Geostationary satellites orbit above the equator with a period matching Earth's rotation.
- Atmospheric drag is stronger at lower altitudes and can aid eventual re-entry.
MCQ 1
Passivation of a spacecraft means:
- A. Removing stored energy that could cause breakup
- B. Increasing fuel pressure after retirement
- C. Changing a satellite into a launch vehicle
- D. Encrypting all ground data
Reveal answerHide answer
A
Residual propellant and stored electrical energy are reduced to lower explosion risk.
MCQ 2
Space situational awareness helps:
- A. Track objects and predict close approaches
- B. Eliminate orbital mechanics
- C. Stop all atmospheric drag
- D. Create geostationary orbit at ground level
Reveal answerHide answer
A
Tracking and conjunction analysis support collision avoidance.
Mains
Question, 10 marks, 150 words: Why does the growth of satellite constellations require stronger global space-traffic governance?
Approach:
- Explain services and congestion.
- Discuss debris, conjunctions, spectrum, and re-entry.
- Identify jurisdiction and data-sharing problems.
- Suggest disposal standards and coordination rules.