ISRO to Launch EOS-05 (GISAT-1A) via GSLV F17 on Sept 4; Replaces Failed GISAT-1

ISRO's Oceansat-3 Captures Sharp Drop in Pacific Marine Productivity as El Niño Warms Ocean

ISRO's Oceansat-3 satellite has detected a sharp decline in chlorophyll-a in the equatorial Pacific Ocean during April-June 2026, linked to the developing El Niño. This reduction in marine productivity threatens the ocean food chain and serves as an early climate indicator ahead of a forecast strong El Niño event from September 2026 to February 2027.

18th BRICS Summit New Delhi Declaration: RSSC Expansion, Space Debris, PAROS Working Group

The 18th BRICS Summit adopted the New Delhi Declaration, underscoring progress in expanding the BRICS Remote Sensing Satellite Constellation (RSSC) to include new space agencies, strengthening space debris mitigation efforts, and advancing discussions on the Prevention of an Arms Race in Outer Space (PAROS) via an open-ended working group. This highlights deepening BRICS cooperation in space technology and security, a key area for UPSC International Relations and Science & Technology segments.

ISRO Launches EOS-05: India's First Geosynchronous Earth-Imaging Satellite for Strategic & Disaster Monitoring

ISRO has successfully launched EOS-05, India's first earth-imaging satellite placed in geosynchronous orbit. Unlike polar-orbiting satellites, it can continuously observe the same area, making it invaluable for real-time disaster response (floods, cyclones, forest fires), agricultural monitoring, and strategic security applications. This marks a significant leap in India's space-based surveillance capabilities.

ISRO's GISAT-1A Launch in September 2026 After Two PSLV Failures; Expert Report Not Published

ISRO is set to launch GISAT-1A in September 2026 after two consecutive PSLV failures in 2025 and early 2026. The mission is crucial for restoring confidence in ISRO's launch capabilities. Additionally, the government's refusal to publish the National Level Expert Committee report raises transparency concerns relevant for governance and accountability.

CAQM-ISRO to Re-Test Burnt Area Protocol as Satellite-Ground Data Diverge in Punjab-Haryana

CAQM's burnt area assessment protocol, used to monitor stubble burning, is under validation due to divergence between satellite and ground data. This impacts air quality enforcement in Delhi-NCR and has been questioned in the Supreme Court, making it critical for environment and governance exams.

SC Applies Section 498A to Live-in Relationships; NOTTO Launches Real-Time Organ Transplant Portal with Aadhaar Pledges

The Indian Express UPSC Key for August 4, 2026, covers multiple crucial topics: the Supreme Court's ruling extending Section 498A cruelty protection to live-in relationships, the launch of a real-time organ transplant portal by NOTTO, the Vikram Sarabhai Medal awarded to Annapurni Subramaniam, India's resilient fertiliser supply amid the Iran war, the science behind Europe's wildfires, and the Ceuta migrant crisis. These topics span Polity, Health, Science, Environment, and International Relations, offering direct material for UPSC Prelims and Mains.

NPCIL Commences Fuel Loading at RAPP-8: 4th Indigenous 700 MWe PHWR in Fleet Mode

NPCIL has started initial fuel loading (IFL) at Unit 8 of Rajasthan Atomic Power Project (RAPP-8), a 700 MWe indigenous pressurised heavy water reactor (PHWR). This marks a major step in India's fleet-mode nuclear expansion, with commercial operation expected in 2026-27. For exams: understand PHWR technology, AERB's role, and the commissioning sequence (IFL → FAC → power generation).

IN-SPACe Releases Planned Re-entry Guidelines: Safety Threshold 1 in 10,000, Mandates Third-Party Liability Insurance

IN-SPACe has released new guidelines for planned re-entry of space objects, establishing a safety threshold of 1 in 10,000 risk to humans and mandating third-party liability insurance for private operators. This is crucial for India's human spaceflight mission Gaganyaan and the growing private space sector.