25 August 2025

• History: Bengali women revolutionaries : Pritilata Waddedar's sacrifice at Chittagong (1932) and the forgotten women of the armed independence movement.
• Economy: Ethanol Blending Programme targets E27 by 2030 : India at E16 nationally in 2025.
• Space: ISRO's IADT-01 test validates air-breathing propulsion : a step toward hypersonic vehicles.
• Defence: IADWS Sudarshan Chakra gives Army short-range drone defence.
• Environment: Invasive Alien Species : IUCN cites them among top five causes of global biodiversity loss.

GS area: History (Modern India, Freedom Struggle)

On August 23, 1932, Pritilata Waddedar led an attack on the Pahartali European Club in Chittagong and consumed potassium cyanide to avoid capture : becoming the first woman to die in India's armed freedom struggle.

• Chittagong Armoury Raid (1930): Masterplanned by Surya Sen (Masterda). A group of revolutionaries raided British armories in Chittagong. The plan was to seize arms, cut telegraph wires and declare temporary independence.
• Surya Sen's execution: Surya Sen was captured and hanged in 1934. The raid inspired a generation of revolutionaries across Bengal.
• Pritilata Waddedar: Born 1911 in Chittagong (now Bangladesh). First woman to lead an armed action in the Indian independence movement. Studied at Bethune College, Calcutta.
• Other women revolutionaries: Bina Das : fired a pistol at Bengal Governor Stanley Jackson during his Convocation address at Calcutta University (February 1932). She received nine years rigorous imprisonment. Kalpana Datta : co-conspirator with Surya Sen, later became a communist activist.
• Context: Women's participation in armed resistance was exceptional in colonial India. Most nationalist movements assigned women supportive roles. The Chittagong group was an outlier.

Static linkage: Modern Indian History, freedom struggle, Bengal.

GS area: Economy (Energy, Agriculture), Environment

India achieved E16 average blending nationally in 2025 and set E27 as the 2030 target under the Ethanol Blending Programme.

• E20 milestone: E20 (20 per cent ethanol blend) was achieved on national highways in February 2025. The target originally was 2030; India achieved it five years early.
• EBP (Ethanol Blending Programme): Launched 2003. Oil Marketing Companies (IOCL, BPCL, HPCL) are mandated to procure ethanol from distilleries for blending.
• Feedstock: Primarily sugarcane molasses and damaged food grains. Second-generation (2G) ethanol from agricultural residue (rice straw) is being scaled up.
• Economic benefits: Rs 76,000 crore saved in foreign exchange (crude oil substitution) since 2014. Over Rs 90,000 crore paid to farmers and distillers.
• Environmental benefit: Reduces tailpipe CO2, particulate matter and unburnt hydrocarbons. E20 cuts CO emissions by 50 per cent and HC emissions by 30 per cent versus E0.
• Challenge for E27: Higher blends require flex-fuel vehicles or engine modifications. Most of India's current fleet is designed for E10 or E20 maximum.

Static linkage: Economy, energy policy, agriculture.

GS area: Science and Technology (Space)

ISRO conducted the first successful test of the Integrated Air-frame and Dual-stage propulsion Technology (IADT-01) : a precursor to a hypersonic cruise vehicle.

• Air-breathing propulsion: Unlike rocket engines that carry both fuel and oxidiser, air-breathing engines take oxygen from the atmosphere. This makes them more fuel-efficient for high-speed atmospheric flight.
• Scramjet basics: A scramjet (Supersonic Combustion Ramjet) operates at hypersonic speeds (above Mach 5). Combustion occurs in a supersonic airstream : unlike standard jet engines where air is slowed to subsonic speeds.
• ISRO's earlier achievement: ISRO successfully demonstrated scramjet technology in 2016 with its Advanced Technology Vehicle (ATV). IADT-01 advances dual-stage propulsion.
• Applications: Hypersonic cruise missiles, reusable launch vehicles (to reduce launch costs), fast-strike weapons and future spaceplane concepts.
• Strategic significance: Only the US, Russia and China have operationally demonstrated hypersonic weapons. India's programme is defence and scientific in scope.

Static linkage: Science and technology, space, defence.

GS area: Defence, Science and Technology

The Indian Army inducted the IADWS (Integrated Air Defence Weapon System) "Sudarshan Chakra" for short-range counter-drone operations.

• Threat context: Cheap commercial drones (DJI Matrice class) have become weapons platforms. Operation Sindoor demonstrated that India must field counter-UAS (Unmanned Aerial Systems) at battalion and brigade level.
• Sudarshan Chakra components: Electro-optical and thermal sensors, radar, jamming systems and kinetic interceptors : integrated into a single mobile platform.
• Range: Effective against drones within a few kilometres altitude and distance : the low-altitude gap that Akash and Barak-8 systems are not designed for.
• Indigenous content: Developed under the DRDO with significant private sector integration (a model post the DPP 2020 reforms).
• Naming: Sudarshan Chakra is a reference to the disc weapon of Vishnu : a circular, spinning weapon. The name signals precision and completeness of coverage.

Static linkage: Defence, technology, counter-drone.

GS area: Environment (Biodiversity)

The IUCN ranked Invasive Alien Species (IAS) among the top five causes of global biodiversity loss in its 2023 assessment : relevant to India's species losses.

• Definition: Species introduced outside their natural range that establish themselves and cause harm to native biodiversity, economies or human health.
• Global reach: 37,000 alien species introduced by human activities globally. About 3,500 are considered harmful IAS.
• Economic cost: $423 billion per year globally in economic damage (2023 IPBES assessment).
• IUCN Red List link: 216 extinct species are directly attributed to IAS. They are among the leading drivers of endemic island species loss.
• India-specific examples: Parthenium hysterophorus (Congress grass/carrot weed), Lantana camara (in forest edges), Water hyacinth (Eichhornia crassipes) in wetlands, African giant snail (Achatina fulica), Red-eared slider turtle.
• Convention on Biological Diversity (CBD): Parties are required to prevent, control or eradicate IAS. India's Biological Diversity Act 2002 has provisions.

Static linkage: Biodiversity, environment, ecology.

GS area: History (Heritage), Governance

A parliamentary panel noted that the Archaeological Survey of India (ASI) had failed to complete the listing of all centrally protected monuments.

• ASI mandate: Protect 3,693 centrally protected monuments and sites across India. This includes World Heritage Sites, nationally important forts, temples and ancient ruins.
• The problem: About 100 monuments were "unlisted" : not formally notified, leaving them without clear legal protection status.
• Prohibited zone: Within 100 metres of a centrally protected monument is a prohibited zone : no construction is allowed. From 100 to 300 metres is a regulated zone. These boundaries cannot be enforced without formal listing.
• Ancient Monuments Act, 1958: Governs the protection of antiquities and art treasures. ASI operates under it.
• Heritage at risk: Unlisted monuments have been encroached upon or damaged. Cities like Aurangabad, Delhi and Mathura have documented cases.

Static linkage: Heritage, governance, ASI.

• Launch Vehicle Mark-3 (LMLV): ISRO was on track for commercial launches of LVM3 (formerly GSLV Mark III). The vehicle can carry 8 tonnes to low Earth orbit and 4 tonnes to geostationary transfer orbit : the most capable Indian rocket. OneWeb constellation launches used LVM3.
• Ethanol 2G plants: IOCL's Panipat 2G ethanol plant (rice straw feedstock) is India's first large commercial 2G ethanol facility. Produces 30,000 KLPA (kilo litres per annum). The technology was developed with IOCL's R&D.
• Asiatic Lion census note: The 2020 census counted 674 lions; the 2025 census (released in August 2025) counted 891 : a 32 per cent increase over five years. All Asiatic lions are in Gir and surrounding protected areas.