Space Debris & Orbital Sustainability: India's Space Situational Awareness
Discover the achievements of Indian space missions, including satellite launches and orbital maneuvers in the Indian Space Situational Assessment Report.
Introduction
"Space is not a dumping ground. What we leave in orbit today becomes the hazard that blocks access to space tomorrow." — European Space Agency, Space Debris Report
The rapid commercialisation of space is transforming Low Earth Orbit (LEO) into a congested highway. In 2025 alone, 315 successful launches placed 4,651 objects in orbit — a net annual growth of 74.5%. As India expands its space ambitions through ISRO, commercial players, and IN-SPACe, the Indian Space Situational Assessment Report (ISSAR) 2025 presents both a progress report and a stark warning: orbital sustainability is becoming as critical as launch capability.
| Parameter | Global Data (2025) |
|---|---|
| Successful space launches | 315 |
| Objects placed in orbit | 4,651 |
| Objects re-entered atmosphere | 1,911 |
| Net annual orbital growth | 74.5% |
| Orbital manoeuvres in LEO | 563 |
| Orbital manoeuvres in GEO | 519 |
| Collision avoidance manoeuvres (LEO) | 14 |
| Collision avoidance manoeuvres (GEO) | 4 |
| Parameter | Indian Data (2025) |
|---|---|
| Satellites launched | 8 |
| Rocket bodies placed in orbit | 4 |
| Indian objects re-entered | 12 |
| Total Indian satellites in orbit | 86 |
| Operational Indian satellites | 27 |
| Defunct satellites still in orbit | 23 |
| Decayed satellites | 36 |
| PSLV rocket bodies in orbit | 42 |
| GSLV rocket bodies in orbit | 4 |
| LVM-3 rocket bodies in orbit | 3 |
Background & Context
What is Space Situational Awareness (SSA)?
- Tracking and monitoring of all objects in Earth's orbit
- Includes active satellites, defunct satellites, rocket bodies, and debris fragments
- Essential for collision avoidance, safe launches, and orbital slot management
Why is it urgent now?
- Mega-constellations (SpaceX Starlink, Amazon Kuiper) are deploying thousands of satellites in LEO
- Each collision generates thousands of new debris fragments — Kessler Syndrome risk
- India's 27 operational satellites and future missions face real collision probability
ISSAR — India's Response:
- Published by ISRO's System for Safe and Sustainable Space Operations Management (IS4OM)
- Annual assessment of India's orbital assets and global space environment
- Key tool for India's space traffic management policy framework
Key Concepts
Kessler Syndrome
- Theoretical cascade scenario proposed by NASA scientist Donald Kessler (1978)
- One collision generates debris → debris causes more collisions → chain reaction
- Could render certain orbital bands permanently unusable
- LEO (where most satellites operate) is most vulnerable
Orbital Regimes
| Orbit | Altitude | Key Use | Debris Risk |
|---|---|---|---|
| LEO | 200–2,000 km | Earth observation, broadband constellations | Highest |
| MEO | 2,000–35,786 km | Navigation (GPS, NavIC) | Moderate |
| GEO | 35,786 km | Communication, weather | High (limited slots) |
| Graveyard orbit | 300 km above GEO | Decommissioned GEO satellites | Growing concern |
Post-Mission Disposal (PMD)
- International guideline: deorbit LEO satellites within 25 years of end of mission
- GEO satellites should be moved to graveyard orbit (~300 km above GEO)
- IRNSS-1D decommissioned 600 km above GEO — raises question of compliance with standard graveyard orbit norms
India's Orbital Footprint — Analysis
Rocket Body Problem:
- 42 PSLV rocket bodies still in orbit — PSLV's upper stage historically left in orbit
- ISRO has been developing PS4 re-start capability and passivation techniques to address this
- Rocket bodies are large objects — high collision consequence if struck
Defunct Satellite Problem:
- 23 defunct Indian satellites still occupying orbital slots
- Dead satellites cannot manoeuvre — purely passive collision risk
- Represents India's historical gap in end-of-life disposal planning
Operational Ratio:
- Only 27 of 86 Indian satellites in orbit are operational = 31% operational rate
- 69% are either defunct or have decayed — reflects legacy of older missions without disposal protocols
Global & Governance Dimensions
International Frameworks:
| Framework | Body | Status |
|---|---|---|
| Space Debris Mitigation Guidelines | UN COPUOS | Voluntary |
| Long-term Sustainability Guidelines (LTS) | UN COPUOS 2019 | Voluntary |
| Inter-Agency Space Debris Coordination Committee (IADC) | 13 space agencies including ISRO | Technical guidelines only |
| Outer Space Treaty 1967 | UN | No debris-specific provisions |
Key Gap: No binding international law on space debris — all guidelines are voluntary, creating a tragedy of the commons in orbital space.
India's Position:
- Member of IADC
- Developing national Space Traffic Management (STM) policy
- IN-SPACe framework now governs private launches — debris norms must extend to commercial operators
Challenges
- No binding global debris law — free-rider problem persists
- Active Debris Removal (ADR) technology still nascent and expensive
- India's large PSLV upper stage legacy requires retroactive mitigation
- Rapid growth of foreign mega-constellations increases collision risk for Indian assets
- Graveyard orbit practices need standardisation — IRNSS-1D disposal raises compliance questions
- Capacity gap in real-time tracking of smaller debris fragments (<10 cm)
Way Forward
- Legislate debris norms domestically — extend IN-SPACe licensing conditions to include mandatory PMD compliance
- Passivation and deorbit capability must be standard on all future ISRO and commercial launches
- Invest in SSA infrastructure — independent Indian tracking network reduces dependence on US Space Surveillance Network data
- Push for binding UN framework — India should lead multilateral advocacy at COPUOS for legally binding debris mitigation
- Active Debris Removal R&D — partner with ESA, JAXA on ADR technology development
Conclusion
Space debris is the climate change of the cosmos — a slow-accumulating, globally shared crisis driven by short-term thinking and absent governance. India's ISSAR 2025 is a commendable step toward transparency and situational awareness. But awareness must translate into action: stricter domestic regulations for launch operators, investment in active debris removal, and diplomatic leadership at the UN for binding international norms. India's growing space ambitions — commercial, strategic, and scientific — can only be sustained if the orbital environment remains navigable. The alternative, a Kessler cascade, would be catastrophic and irreversible.
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What does the Indian Space Situational Assessment Report (ISSAR) indicate about the current state of space activity and orbital congestion?
The Indian Space Situational Assessment Report (ISSAR) 2025 highlights the rapidly increasing scale of global space activity and the resulting congestion in Earth’s orbit. With 315 successful launches and 4,651 objects placed in orbit in a single year, the report underscores an unprecedented surge in space operations. This expansion is driven by the proliferation of satellite constellations, commercial space ventures, and national space programs.
Key observations from the report include:
The findings suggest that Earth's orbits, especially Low Earth Orbit (LEO), are becoming increasingly crowded. This congestion raises concerns about space debris, collision risks, and sustainability of space operations.
From a broader perspective, ISSAR serves as a critical tool for policymakers and space agencies by providing data-driven insights into orbital dynamics. It emphasizes the urgent need for global coordination, responsible space behaviour, and regulatory frameworks to ensure long-term sustainability of outer space.
Key observations from the report include:
- A net annual growth of 74.5% in orbital objects, indicating accelerated accumulation
- A large number of re-entries (1,911), reflecting the lifecycle turnover of satellites and debris
- Significant orbital manoeuvres and collision avoidance measures, pointing to rising risks
The findings suggest that Earth's orbits, especially Low Earth Orbit (LEO), are becoming increasingly crowded. This congestion raises concerns about space debris, collision risks, and sustainability of space operations.
From a broader perspective, ISSAR serves as a critical tool for policymakers and space agencies by providing data-driven insights into orbital dynamics. It emphasizes the urgent need for global coordination, responsible space behaviour, and regulatory frameworks to ensure long-term sustainability of outer space.
Why is the issue of space debris and orbital congestion becoming a major concern for countries like India?
Space debris and orbital congestion have emerged as critical challenges due to the exponential increase in space activities. As highlighted by ISSAR 2025, thousands of objects are being launched annually, many of which become defunct but remain in orbit. These non-functional objects pose collision risks to operational satellites, which are essential for communication, navigation, weather forecasting, and national security.
Major concerns include:
For India, with 86 satellites in orbit (only 27 operational), the presence of defunct satellites increases vulnerability. Moreover, India’s growing reliance on space-based infrastructure for governance and development amplifies the stakes.
Globally, incidents such as the 2009 Iridium-Cosmos collision demonstrate the real dangers of debris. Thus, addressing space debris is not just a technical issue but a strategic and economic imperative requiring international cooperation and robust space governance frameworks.
Major concerns include:
- Collision risks: Even small debris can damage or destroy satellites due to high velocities
- Kessler Syndrome: A cascading effect where collisions generate more debris, increasing future risks
- Economic losses: Damage to costly satellites can disrupt services and incur huge financial costs
For India, with 86 satellites in orbit (only 27 operational), the presence of defunct satellites increases vulnerability. Moreover, India’s growing reliance on space-based infrastructure for governance and development amplifies the stakes.
Globally, incidents such as the 2009 Iridium-Cosmos collision demonstrate the real dangers of debris. Thus, addressing space debris is not just a technical issue but a strategic and economic imperative requiring international cooperation and robust space governance frameworks.
How do space agencies manage collision risks and ensure the safety of satellites in increasingly crowded orbits?
Space agencies employ a combination of monitoring, predictive analytics, and manoeuvring strategies to manage collision risks. The ISSAR 2025 report indicates that India conducted 563 orbital manoeuvres in Low Earth Orbit (LEO) and 519 in Geostationary Orbit (GEO), along with multiple collision avoidance actions. These measures are part of a broader framework known as Space Situational Awareness (SSA).
Key mechanisms include:
India’s SSA capabilities are evolving, with ISRO and other agencies integrating global data and indigenous systems. For example, collision avoidance manoeuvres are executed when the probability of collision crosses a threshold.
Internationally, agencies like NASA and ESA also share data to enhance safety. However, increasing traffic demands more automated and AI-driven systems for real-time decision-making. Ensuring orbital safety is thus a continuous and resource-intensive process, requiring both national capabilities and global collaboration.
Key mechanisms include:
- Tracking and surveillance: Using ground-based radars and telescopes to monitor space objects
- Conjunction analysis: Predicting potential close approaches between objects
- Collision avoidance manoeuvres: Adjusting satellite orbits to prevent impact
India’s SSA capabilities are evolving, with ISRO and other agencies integrating global data and indigenous systems. For example, collision avoidance manoeuvres are executed when the probability of collision crosses a threshold.
Internationally, agencies like NASA and ESA also share data to enhance safety. However, increasing traffic demands more automated and AI-driven systems for real-time decision-making. Ensuring orbital safety is thus a continuous and resource-intensive process, requiring both national capabilities and global collaboration.
What factors are driving the rapid increase in satellite launches and orbital objects in recent years?
The surge in satellite launches and orbital objects is driven by technological, economic, and strategic factors. The commercialization of space, coupled with advancements in miniaturization and reusable launch vehicles, has significantly reduced the cost of accessing space. This has enabled private players and startups to enter the space sector, leading to a dramatic increase in launches.
Key driving factors include:
India’s own expansion, including navigation systems like IRNSS and increased launch capabilities (PSLV, GSLV, LVM-3), reflects this trend. Additionally, emerging sectors such as space tourism and asteroid mining may further accelerate growth.
While this expansion offers immense opportunities, it also raises concerns about sustainability and governance. Thus, the rapid increase in orbital objects is both a sign of technological progress and a challenge requiring careful regulation and planning.
Key driving factors include:
- Satellite constellations: Projects like Starlink and OneWeb deploying thousands of small satellites
- Growing demand for data: Expansion of internet services, remote sensing, and navigation systems
- National security concerns: Countries investing in space assets for surveillance and defense
India’s own expansion, including navigation systems like IRNSS and increased launch capabilities (PSLV, GSLV, LVM-3), reflects this trend. Additionally, emerging sectors such as space tourism and asteroid mining may further accelerate growth.
While this expansion offers immense opportunities, it also raises concerns about sustainability and governance. Thus, the rapid increase in orbital objects is both a sign of technological progress and a challenge requiring careful regulation and planning.
Critically analyze India's space asset management in light of ISSAR 2025 findings.
India’s space asset management reflects both progress and emerging challenges in a rapidly evolving space environment. The ISSAR 2025 data shows that India has 86 satellites in orbit, but only 27 are operational, with a significant number being defunct or decayed. This indicates the growing issue of space debris and lifecycle management of satellites.
Strengths of India’s approach:
Challenges and concerns:
For instance, the decommissioning of IRNSS-1D shows awareness of responsible practices, but more systematic measures are required. Compared to global leaders, India is still developing comprehensive debris mitigation technologies.
Overall, while India has made significant strides, it must enhance sustainability practices, invest in debris removal technologies, and align with global norms to ensure long-term viability of its space program.
Strengths of India’s approach:
- Robust launch capabilities through PSLV, GSLV, and LVM-3
- Increasing focus on Space Situational Awareness and collision avoidance
- Strategic use of satellites for development and governance
Challenges and concerns:
- High proportion of defunct satellites still in orbit
- Limited active debris removal capabilities
- Need for stronger regulatory frameworks for end-of-life disposal
For instance, the decommissioning of IRNSS-1D shows awareness of responsible practices, but more systematic measures are required. Compared to global leaders, India is still developing comprehensive debris mitigation technologies.
Overall, while India has made significant strides, it must enhance sustainability practices, invest in debris removal technologies, and align with global norms to ensure long-term viability of its space program.
How can India's experience with collision avoidance and orbital management serve as an example for emerging space-faring nations?
India’s experience in managing orbital operations provides valuable lessons for emerging space-faring nations. The ISSAR 2025 report highlights India’s proactive approach, including conducting multiple collision avoidance manoeuvres and maintaining detailed tracking of space objects. This demonstrates the importance of integrating safety measures into space operations from the outset.
Key lessons include:
For example, India’s handling of crowded LEO conditions through timely manoeuvres shows how even resource-constrained countries can ensure safety through efficient management. This is particularly relevant for countries in Asia and Africa entering the space domain.
Thus, India’s model emphasizes a balance between expansion and responsibility, offering a scalable framework for sustainable space operations in the developing world.
Key lessons include:
- Early investment in SSA systems: Enables accurate tracking and risk prediction
- Operational discipline: Regular manoeuvres to maintain safe orbits
- Data sharing: Collaboration with international agencies for better situational awareness
For example, India’s handling of crowded LEO conditions through timely manoeuvres shows how even resource-constrained countries can ensure safety through efficient management. This is particularly relevant for countries in Asia and Africa entering the space domain.
Thus, India’s model emphasizes a balance between expansion and responsibility, offering a scalable framework for sustainable space operations in the developing world.
Using ISSAR 2025 as a case study, discuss the need for global governance mechanisms in outer space.
ISSAR 2025 serves as a compelling case study highlighting the urgent need for robust global governance in outer space. The dramatic increase in orbital objects and collision risks reflects the absence of comprehensive and enforceable international regulations. While treaties like the Outer Space Treaty (1967) provide a basic framework, they are insufficient to address modern challenges such as space debris and commercial activities.
Key governance gaps include:
The increasing number of collision avoidance manoeuvres and near-miss incidents underscores the risks of unregulated space activity. For instance, mega-constellations by private companies raise concerns about equitable access and orbital crowding.
Way forward:
India, through initiatives like ISSAR, can play a proactive role in shaping global norms. Ultimately, ensuring the long-term sustainability of space requires collective action, as space is a shared global commons.
Key governance gaps include:
- Lack of binding rules on debris mitigation and removal
- Inadequate coordination among countries and private actors
- Absence of enforcement mechanisms for irresponsible behaviour
The increasing number of collision avoidance manoeuvres and near-miss incidents underscores the risks of unregulated space activity. For instance, mega-constellations by private companies raise concerns about equitable access and orbital crowding.
Way forward:
- Developing international norms for sustainable space operations
- Promoting data sharing and transparency
- Encouraging public-private partnerships for debris removal
India, through initiatives like ISSAR, can play a proactive role in shaping global norms. Ultimately, ensuring the long-term sustainability of space requires collective action, as space is a shared global commons.
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