Earth Observation Satellites (EOS) serve both civilian and strategic purposes. Discuss the significance of the EOS series for India's national security and disaster management, and the impact of recent mission failures on these objectives.

Q. Earth Observation Satellites (EOS) serve both civilian and strategic purposes. Discuss the significance of the EOS series for India's national security and disaster management, and the impact of recent mission failures on these objectives. (15 marks, 250-350 words)

India's EOS series — the renamed remote-sensing fleet carrying optical and radar payloads into Sun Synchronous Orbit — is a classic dual-use asset, underpinning both defence surveillance and civilian emergency response. Two consecutive PSLV failures have now exposed how thin this capability actually is.

Significance for national security - All-weather, day-night imaging: EOS-09 carried a Synthetic Aperture Radar payload for a five-year mission life, enabling cloud-penetrating surveillance [1]. - Dedicated strategic assets: EOS-N1, the primary payload of PSLV-C62, was built for strategic purposes — reconnaissance over borders and maritime approaches [2]. - Sun Synchronous Orbit gives consistent-illumination repeat passes, essential for change detection along the LAC and coastline. - Indigenous imaging reduces dependence on foreign commercial imagery during crises.

Significance for disaster management - NRSC's Decision Support Centre and the National Database for Emergency Management (NDEM), run for the Ministry of Home Affairs, use EOS data for floods, cyclones, drought, landslides and forest fires [3]. - Supports hazard zonation, preparedness, damage assessment and emergency response for all States/UTs [3]. - Rapid post-event mapping guides NDRF deployment and relief allocation.

Impact of recent mission failures - PSLV-C61 (18 May 2025) lost EOS-09 after a third-stage observation [1]; PSLV-C62 (12 January 2026), the 64th PSLV flight, lost EOS-N1 and 14 co-passengers to a roll-rate disturbance near the end of PS3 [2]. - Both anomalies occurred in the same third stage, suggesting a systemic rather than random fault; ISRO had already constituted a probe panel after C61 [4]. - Twin losses thin the observation constellation, stretching revisit intervals just as disaster and surveillance demand grows, and dent the commercial credibility of NSIL-operated launches [2].

Reliability, not capability, is India's binding constraint today. A transparent failure-analysis process, a full design review of the solid third stage, and diversification across SSLV, GSLV and IN-SPACe-authorised private launchers can restore assured access. Rebuilding EOS coverage remains central to India's security preparedness and its Sendai Framework commitment to disaster resilience.

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Sources: 1. PSLV-C61/EOS-09 Mission — ISRO — EOS-09 SAR payload, SSO, five-year life; third-stage anomaly ended the mission 2. PSLV-C62 anomaly: ISRO investigates roll disturbance during third stage of EOS-N1 mission — News on Air (Prasar Bharati) — 64th PSLV flight, EOS-N1 with 14 co-passengers, roll-rate disturbance near end of PS3 3. Disaster Management Support — National Remote Sensing Centre, ISRO — NDEM and Decision Support Centre; flood, cyclone, drought, landslide and forest-fire support for MHA and States/UTs 4. ISRO forms probe panel after PSLV-C61 glitch leaves EOS-09 off target — News on Air (Prasar Bharati) — failure analysis committee constituted after the May 2025 failure