The 2024 Indian Space Situational Assessment Report (ISSAR) was released by Dr V. Narayanan, head of the Indian Space Research Organisation (ISRO) and Secretary of the Department of Space, on April 22, 2025. This report was prepared by ISRO’s System for Safe and Sustainable Space Operations Management (IS4OM), which focuses on keeping space operations safe and sustainable.
About the Report
ISRO carries out Space Situational Awareness (SSA) activities for protecting India’s space assets which could be harmed by threats such as space debris, asteroids, meteoroids, radiation, and particle flux. ISRO’s IS4OM manages all efforts to keep space safe and sustainable and helps ensure compliance of global rules for space safety.
One of ISRO’s main tasks is to check if space objects might get too close to satellite or rockets. It further predicts when objects might fall back into Earth’s atmosphere. IS4OM also studies how the number of space objects are changing.
This report is prepared by ISRO every year, and gives a summary of the current space situation. It is shared with the people and groups who need the information.
Some Highlights of the Report
Global Scenario in Space Activities The year 2024 marked a new high in global space activity, registering the greatest number of launch attempts since the dawn of space age. A total of 261 launches were attempted worldwide with 254 achieving success. Some 2,578 operational satellites were placed in orbit. Overall, 2,963, objects were launched—slightly lower than 3,235 objects, launched in 2023 from 212 launches.
Moreover, a notable trend was the surge in lunar exploration, with five lunar missions launched during the year. This reflects a renewed global interest in exploring the Moon for various reasons.
One the other hand, the year 2024 also brought concerns related to space sustainability. There occurred three significant on-orbit fragmentation events, the most severe of which involved the fragmentation of a Long March rocket stage (CZ-6A), which added nearly 650 catalogued objects of debris. Some of these fragments decayed in the same year, adding 702 fragmented objects. Thus, a total of 3,665 objects from 254 launches and on-orbit break-ups were added to the space object population.
Atmospheric Re-Entires Adding to the complexity, 2024 also saw a record number of atmospheric re-entries. A total of 2,095 catalogued objects re-entered the Earth’s atmosphere, including 335 Starlink satellites, retired after 11 years to phase out older V1 satellites. The high number of re-entries was influenced by heightened solar activity as the peak of the Solar Cycle 25 approached. This led to 18 strong (G3-class), 20 severe (G4-class), and two extreme (G5-class) geomagnetic storms, which accelerated orbital decay.
Despite fewer satellite launches and higher re-entries to the Earth’s atmosphere as compared to 2023, the total number of debris in orbit increased, primarily due to the fragmentation events. Thus, continuing the upward trend in space object population in 2024!
Indian Scenario in Space Activities India also played a key role in the global space landscape during 2024. By the end of the year, a total of 136 Indian spacecraft, including those from private operators and academic institutions, were launched into Earth orbit. Among these, 22 satellites operated in Low Earth Orbit (LEO) and 31 in Geosynchronous Earth Orbit (GEO), all owned by the Government of India.
India’s two deep space missions—Chandrayaan-2 Orbiter (CH2O) and Aditya-L1 at the Sun-Earth Lagrange point—continued to operate effectively. The propulsion module of Chandrayaan-3 continued to operate in a high Earth orbit after relocation from its luner orbit in November 2023.
In 2024, five launches were carried out from Sriharikota—(i) PSLV-C58/XPoSat, (ii) PSLV-C59/PROBA-3, (iii) PSLV-C60/SPADEX, (iv) GSLV-F14/INSAT-3DS, and (v) SSLV-D3/EOS-08. All missions successfully placed their payloads into designated orbits. Additionally, India launched GSAT-20 and TSAT-1A aboard SpaceX’s Falcon-9 rockets. Overall, one foreign and eight Indian satellites were placed in their intended orbits, along with six rocket bodies, including PSLV Orbital Experiment Modules-3 and 4 (POEM-3 and POEM-4).
Tracking of Indian Space Objects and Re-Entries As of 2024, some remnants from earlier missions still linger in orbit. For instance, the PSLV-C3 upper stage, that broke up in 2001, and created 371 pieces of debris. Though most have re-entered, 41 fragments remained in orbit by the end of 2024.
In terms of atmospheric re-entry, 34 Indian rocket bodies had re-entered the Earth’s atmosphere by the end of 2024, with five of these occurring in 2024 itself. Notably, only one from Launch Vehicle Mark3 (LVM3) M2 (One Web India-1) and two from Geosynchronous Satellite Launch Vehicle—GSLV-F12 and GSLV-F14—remained in orbit. Additionally, 31 Indian satellites have re-entered the atmosphere so far, including nine during 2024 alone. Among them was Carosat-2, which was India’s first LEO satellite to be de-orbited at end-of-life to significantly shorten its orbital lifetime from more than 30 to less than four years.
Mitigating Collision Risks for Indian Satellites ISRO remains vigilant in monitoring the safety of its space assets. It conducts regular analyses under the Space Object Proximity Analysis (SOPA) to predict possible close approaches. In 2024, over 53,000 alerts, issued by Combined Space Operation Center (CSpOC) of the United States Space Command (USSPACECOM) were reviewed, using accurate orbital data from flight dynamics.
As a result, ISRO carried out ten Collision Avoidance Manoeuvres (CAMs), six in LEO and four in GEO. An additional manoeuvre was executed for the Chandrayaan-2 Orbiter when a close approach with the National Aeronautics and Space Administration (NASA’s) Lunar Reconnaissance Orbiter was predicted. In many cases, CAMs were incorporated into planned orbit maintenance manoeuvres, reducing the need for separate operations.
Orbit manoeuvres to maintain satellite positions with mission-defined parameters were also carried out: 681 in LEO, 504 in GEO (excluding 1,222 pulsing manoeuvres), and 21 in deep space (including 14 for Chandrayaan-2 orbiter, and five for Aditya L-1). In several cases, manoeuvre plans were revised post-execution to avoid potential conjunctions showcasing a proactive and responsive approach to orbital safety.
The same approach for conjunction assessment and collision risk mitigation was applied to deep-space missions. For the CH2O, 14 orbit maintenance manoeuvres were performed, with adjustments made on eight occasions. In one instance, a planned manoeuvre was advanced to avoid a potential close approach with NASA’s Lunar Reconnaissance Orbiter (LRO).
Although only four other spacecraft are currently operating near Aditya-L1, each separated by over one lakh kilometres, regular close approach assessments are conducted to ensure situational awareness. All necessary coordination for spaceflight safety was carried out for the operational satellites.
Launch Vehicle Safety and COLA Procedures To ensure safety during launches, ISRO follows the Collision Avoidance Analysis (COLA) process for all vehicles. In 2024, all missions were cleared for nominal launch times, except for PSLV-C60/SPADEX, which faced a minor delay of over two minutes due to COLA findings. Spaceflight safety coordination was carried out with satellite operators to resolve potential conflicts.
Spacecraft Decommissioning and POEM The ISRO further demonstrated responsible end-of-life practices. Scatsat-1 was decommissioned on September 26, 2024, exactly eight years after its launch, following 12 manoeuvres to deplete the remaining fuel. Two other LEO satellites, INS-2B and EOS-7, were also decommissioned before re-entering the atmosphere.
Upper stages of PSLV-C58 and PSLV-C60 were de-orbited to 350 kilometres, where atmospheric drag ensured re-entry within about three months. On April 4, 2025, the re-entry of PS4 stage of PSLV-C60 happened.
Two POEM missions, PSLV-C58 and PSLV-C60, carried nine and 24 payloads, respectively, for technology demonstrations. Their upper stages were de-orbited to 350 kilometres, passivated, and used as platforms, offering a cost-effective alternative to launching separate satellites.
International Engagement and Policy Initiatives India has remained active in global space governance forums. ISRO participates in key international working groups, including the Inter-Agency Debris Coordination Committee (IADC), International Academy of Astronautics (IAA), International Astronautical Federation (IAF), International Organization for Standardization (ISO), and UN Committee on the Peaceful Uses of Outer Space (UN-COPUOS) fora. In 2024, India chaired the UN working group on the Long-term Sustainability of Outer Space and hosted the 42nd annual IADC meeting in Bengaluru for the period 2023-24. Around 75 foreign delegates from leading space agencies attended the event.
ISRO played a crucial role in updating IADC’s space debris mitigation guidelines, released in January 2025, and contributed to ongoing discussions on debris management in lunar orbits. It further participated in the annual global re-entry prediction campaigns conducted by the IADC.
India’s Commitment to Debris-Free Space Missions A landmark development in 2024 was India’s announcement of its intent to adopt Debris-Free Space Missions (DFSM) by 2030. The initiative aims for all Indian missions, both governmental and private, to ensure near-complete compliance with Post-Mission Disposal (PMD) requirements.
DFSM promotes the disposal of satellites and upper stages with a success probability exceeding 99 per cent. Special focus is on LEO missions, where post-mission residual lifetime must be limited to five years through either controlled re-entry or de-orbiting to a lower orbit. Mission extensions should be suggested only after evaluating the health of the sub-systems, including backup systems to ensure PMD capability remains intact. The initiative also advocates reserving orbital bands around 400 ±30 kilometres specifically for human space missions.
Way forward
The data from 2024 reveals a highly active year in space, with highest number of launches and re-entries to date. It further highlights rising congestion in orbits, especially in LEO. With increasing access to space and the rise of mega-constellations, the importance of Space Traffic Management (STM) has become more evident. However, a global framework for STM is still lacking, requiring continued coordination between satellite operators on a case-by-case basis.
To strengthen its capabilities in Space Situational Awareness (SSA), ISRO is advancing the NEtwork for space object TRacking and Analysis (NETRA) project. Radar installations in Assam, an optical telescope in Ladakh, and the revival of the Multi-Object Tracking Radar (MOTR) system at Sriharikota, are key developments aimed at boosting India’s ability to track and analyse space objects.
India’s declaration of DFSM initiative signals its strong commitment to the responsible and sustainable use of space. ISRO is set to continue expanding its SSA infrastructure, engaging in global discussions, and promoting best practices for space safety and sustainability in the years ahead.
© Spectrum Books Pvt Ltd.
