ISRO successfully launches Earth observation satellite EOS-05

Science & Technology - Space · 4 September 2026 · Based on The Hindu (original report)

2-minute summary

The Indian Space Research Organisation (ISRO) successfully launched the advanced Earth observation satellite, EOS-05, onboard the Geosynchronous Satellite Launch Vehicle (GSLV-F17) from the Satish Dhawan Space Centre in Sriharikota. Weighing 2,367 kg, EOS-05 is India’s first-ever imaging satellite designed to monitor the Earth from a Geosynchronous orbit situated approximately 36,000 km above the surface. Dubbed an 'Eye in the Sky', the satellite provides real-time imagery to aid in agriculture, environmental monitoring, and disaster management, while also supplying critical strategic data. This mission marks the 19th flight of the GSLV and the 107th launch from Sriharikota. The successful deployment serves as a major morale booster and recovery for ISRO, following a period of cautious suspension of launch activities after previous setbacks, including the failure of the GSLV-F10/EOS-03 mission in August 2021—which EOS-05 directly replaces—and the PSLV-C62 mission failure earlier in 2026.

Why it's in the news

ISRO successfully launched India's first-ever Geosynchronous orbit Earth observation imaging satellite, EOS-05, using the GSLV-F17 rocket from Sriharikota, marking a vital recovery following past launch vehicle anomalies.

Background and context

India's Earth observation satellite (EOS) program has historically relied heavily on Low Earth Orbit (LEO) and Sun-Synchronous Polar Orbits (SSPO) using the Polar Satellite Launch Vehicle (PSLV). However, monitoring dynamic terrestrial phenomena, weather patterns, and strategic domains in real-time requires continuous observation from a fixed perspective, which is enabled by Geosynchronous Earth Orbits (GEO). The Geosynchronous Satellite Launch Vehicle (GSLV), equipped with an indigenous cryogenic upper stage, has undergone iterative optimization in structural mass and propulsion systems to handle heavier payloads. The successful launch of EOS-05 successfully fills the gap left by the unsuccessful GSLV-F10/EOS-03 mission of August 2021, where the cryogenic upper stage ignition failed, and restores momentum to India's high-orbit imaging capabilities.

Previous UPSC questions on this theme

• Prelims GS-1 2018 — With reference to India's satellite launch vehicles, consider the following statements : 1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites. 2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth. 3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines. Which of the statements given above is/are correct ? (a) 1 only (b) 2 and 3 (c) 1 and 2 (d) 3 only

Mains practice: Discuss the strategic and socio-economic significance of deploying Earth observation satellites in Geosynchronous orbits as opposed to Low Earth Orbits.

Introduction:

The successful deployment of India's first Geosynchronous Earth observation imaging satellite, EOS-05, via the GSLV-F17 marks a paradigm shift from traditional Low Earth Orbit (LEO) remote sensing to continuous, real-time high-altitude monitoring.

Body:

• Real-Time Monitoring: Unlike LEO satellites that pass over a region intermittently based on orbital periods, Geosynchronous orbits (approx. 36,000 km) allow the satellite to maintain a constant relative position, offering uninterrupted, real-time data streams.

• Disaster Management and Early Warning: Continuous observation drastically enhances India's disaster management framework by providing live tracking of rapidly developing weather aberrations, cyclones, floods, and forest fires.

• Agriculture and Resource Management: High-frequency imaging supports precision agriculture, crop health estimation, and water resource management, directly contributing to food security and rural resilience.

• Strategic and Defence Utilities: Geo-orbit imaging satellites act as an 'Eye in the Sky', providing critical, uninterrupted strategic surveillance capabilities essential for national security and border monitoring.

• Technological Maturation: The mission underscores India's mastery over heavy-lift Geosynchronous Satellite Launch Vehicle (GSLV) technology, validating indigenous propulsion systems and cryogenic upper-stage advancements.

Conclusion:

By expanding Earth observation capabilities into Geosynchronous orbits, India has bolstered both its strategic preparedness and socio-economic planning framework, paving the way for advanced space-based governance.

Prelims practice questions

Q1. Consider the following statements regarding the EOS-05 satellite launched by ISRO: 1. It is India's first-ever imaging satellite designed to monitor the Earth from a Geosynchronous orbit. 2. It was launched using the Polar Satellite Launch Vehicle (PSLV). Which of the statements given above is/are correct?

1. 1 only
2. 2 only
3. Both 1 and 2
4. Neither 1 nor 2

Answer: A. Statement 1 is correct: EOS-05 is India’s first-ever imaging satellite to monitor from a Geosynchronous orbit about 36,000 km above the Earth. Statement 2 is incorrect: It was launched using the Geosynchronous Satellite Launch Vehicle (GSLV-F17), not the PSLV.

Q2. In the context of space technology, what is the primary advantage of placing an Earth observation satellite in a Geosynchronous orbit compared to a Low Earth Orbit (LEO)?

1. It experiences zero atmospheric drag and requires minimal fuel to launch.
2. It completely eliminates the need for launch vehicles with cryogenic upper stages.
3. It provides continuous, real-time imaging and monitoring of a specific region.
4. It operates much closer to the Earth, providing significantly higher optical resolution.

Answer: C. Geosynchronous orbit satellites match the Earth's rotational speed, allowing them to provide continuous and real-time monitoring over a designated coverage area, unlike LEO satellites which provide only intermittent overpasses.

Q3. The Satish Dhawan Space Centre, from where ISRO conducts its rocket launches, is located in which of the following states?

1. Odisha
2. Andhra Pradesh
3. Kerala
4. Tamil Nadu

Answer: B. The Satish Dhawan Space Centre (SDSC) is located in Sriharikota, Andhra Pradesh.

Revision flashcards

• What is the key orbital distinction of the EOS-05 satellite? It is India's first imaging satellite to operate from a Geosynchronous orbit (~36,000 km above Earth).
• Which launch vehicle was used to deploy the EOS-05 satellite? The Geosynchronous Satellite Launch Vehicle (GSLV-F17).
• What is the primary operational objective of the EOS-05 mission? To provide real-time imagery for agriculture, environmental monitoring, disaster management, and strategic surveillance.
• Which unsuccessful mission does EOS-05 directly replace in ISRO's timeline? The GSLV-F10 / EOS-03 mission of August 2021, which failed due to a cryogenic upper stage anomaly.
• Where is India's primary spaceport, the Satish Dhawan Space Centre, located? Sriharikota, Andhra Pradesh.