BENGALURU: The USA-led multinational command centre, Combined Space Operations Centre of the United States Command, has issued over 1,50,000 space debris and collision alerts for Indian Space Research Organisation’s (ISRO) earth orbiting satellites, according to the Indian Space Situational Awareness Report for 2025 (ISSAR-2025).
In the report, ISRO noted that there were four collision avoidance manoeuvres (CAM) for Geostationary Earth Orbit (GEO), while 14 CAMs – including one for NASA-ISRO Synthetic Aperture Radar (NISAR) – were performed for the Low Earth Orbit (LEO) satellites.
The report was released by ISRO on Thursday for the public to assess. It was announced on April 8 during the international conference on spacecraft mission operations-2026, in Bengaluru.
ISRO said wherever feasible, collision avoidance requirements were being met by adjusting orbit maintenance manoeuvres to avoid exclusive CAMs. They also noted that all manoeuvre plans, including those from CAMs, were subject to close approach risk analysis to rule out any potential close approaches with other space objects in the vicinity. They accounted revising 82 manoeuvre plans to avoid post-manoeuvre close approaches with other space objects for LEO satellites. Similarly, on two occasions, manoeuvre plans had to be revised to avoid post-manoeuvre conjunctions for GEO satellites.
Conjunction assessment and collision risk mitigation were also being followed for deep-space missions. Citing the case of Chandrayaan-2 orbiter, ISRO scientists said 16 orbital manoeuvres were carried out in the lunar orbit and on two occasions (January 1 and July 24, 2025), the orbits were readjusted to avoid collisions with NASA’s Lunar Reconnaissance Orbiter (LRO).
The first instance of collision that was addressed by ISRO and NASA scientists was on October 18, 2021. Since then many technological interventions are being used for early detection of objects in orbit. ISRO scientists added that for spaceflight security, they have also been coordinating with many agencies, particularly for Chandrayaan-2 with Firefly Aerospace, Intuitive Machines and iSpace.
The ISSAR-2025 report also detailed how the IRNSS-1D, the fourth of the seven Indian Regional Navigation Satellite Systems, was raised to a graveyard orbit, nearly 600 km above the geostationary belt and made inactive. ISRO said this was the first-ever disposal of an Indian satellite operating in an inclined geosynchronous orbit.
The Cartosat-2A satellite, launched in 2008, was also dealt with in the same way when it became non-operational in 2025.
Following the objective for a debris-free space environment, the Technology Experiment Satellite and POEM-4 re-entered Earth’s atmosphere through natural decay. Also, two more upper stages of the SSLV-D3 mission – the Velocity Trimming Module (VTM) and the solid stage (SS3) – re-entered the atmosphere.
Eight debris objects originating from the fragmentation of PSLV C3 re-entered the atmosphere in 2025, while 33 remained in orbit as of 31 December 2025. The total number of Indian objects re-entering the atmosphere in 2025 was 12.