India’s space agencies issued more than 150,000 collision alerts for Indian satellites in 2025. These alerts aimed to prevent potential in-orbit collisions and safeguard satellite operations. The alerts were generated by tracking space debris and other satellites in low Earth orbit and geostationary orbit.
Collision Alert Mechanism
The alerts were based on data from the Indian Space Situational Awareness and Management (ISAM) programme. ISAM uses radar and optical sensors to monitor space objects. Alerts are issued when predicted conjunctions fall below a threshold distance. Satellite operators receive notifications to perform collision avoidance manoeuvres.
Satellites Involved
Alerts covered satellites from various Indian organisations including ISRO, NSIL, and private operators. The majority of alerts concerned satellites in low Earth orbit (LEO) used for communication, navigation, and earth observation. Geostationary satellites also received alerts due to the increasing congestion in the geostationary belt.
Space Debris and Risk Factors
The rise in collision alerts correlates with increased space debris and satellite launches. Fragmentation debris, defunct satellites, and spent rocket stages contribute to collision risks. The 2025 data showed a 20% increase in alerts compared to 2024, indicating growing orbital congestion.
Collision Avoidance Outcomes
Indian satellite operators executed multiple avoidance manoeuvres based on the alerts. These manoeuvres adjusted satellite orbits to maintain safe distances. No major collision incidents involving Indian satellites were reported in 2025. The alert system enhanced operational safety and satellite lifespan.
What to Study for UPSC Exams?
- Space Situational Awareness Programmes
- Orbital Debris Management Policies
- Satellite Collision Avoidance Techniques
- Geostationary Orbit Congestion Issues
Space Situational Awareness Programmes
Space Situational Awareness (SSA) involves tracking and predicting the movement of space objects to prevent collisions. SSA uses radar, telescopes, and onboard sensors to monitor debris and satellites. Countries like the US, Russia, and India have dedicated SSA systems to ensure space traffic management and safety.
Orbital Debris Management Policies
Orbital debris management includes guidelines to limit space junk creation, such as post-mission disposal and passivation of satellites. The UN’s Space Debris Mitigation Guidelines recommend debris reduction measures. Some nations enforce debris caps and active debris removal missions to reduce collision risks.
Satellite Collision Avoidance Techniques
Collision avoidance involves maneuvering satellites using thrusters to change orbit paths temporarily. Techniques include conjunction assessment, collision probability calculation, and timely alerts. Autonomous onboard systems and ground commands coordinate to execute avoidance maneuvers, minimizing operational disruptions.
Geostationary Orbit Congestion Issues
The geostationary orbit (GEO) is a fixed orbital belt 35,786 km above Earth, heavily used for communication satellites. GEO congestion arises from limited orbital slots and increasing satellite launches. Coordination and spacing protocols by the ITU regulate GEO usage to prevent interference and collisions.
Last Modified: April 17, 2026