CURRENT AFFAIRS | MARCH 2026
Prelims: uGMRT specifications, NCRA-TIFR, SFDR missile technology, DRDO labs, IDS for railways, DAS technology, Rayleigh scattering
Mains: GS-III (Science and Technology — achievements of Indians in S&T, defence technology, indigenisation, infrastructure modernisation through technology)
J1007+3540: India’s uGMRT Discovers Giant Radio Galaxy
Indian radio astronomers achieved a significant breakthrough with the discovery of J1007+3540, a giant radio galaxy, using the upgraded Giant Metrewave Radio Telescope (uGMRT) located near Pune. This discovery underscores India’s growing capabilities in radio astronomy and the world-class status of its indigenous astronomical infrastructure.
The uGMRT is one of the most powerful radio telescopes in the world for observations at metre wavelengths. It consists of 30 fully steerable antennas, each 45 metres in diameter, spread over a baseline of 25 km. This configuration creates an interferometric array with the resolving power equivalent to a single telescope with a 25-km aperture, enabling it to detect extremely faint radio signals from distant cosmic objects.
– Location: Near Pune, Maharashtra
– Configuration: 30 antennas, each 45-m diameter
– Baseline: 25 km
– Operated by: National Centre for Radio Astrophysics, Tata Institute of Fundamental Research (NCRA-TIFR)
– Speciality: World’s most sensitive telescope at metre wavelengths
– Discovery: J1007+3540 giant radio galaxy
Giant radio galaxies are among the largest single structures in the universe, with radio lobes extending over millions of light-years from the central active galactic nucleus (AGN). These objects are powered by supermassive black holes at the centres of galaxies, which eject jets of relativistic particles that interact with the intergalactic medium to produce radio emission. The discovery of J1007+3540 contributes to our understanding of how AGN feedback shapes the evolution of galaxies and the large-scale structure of the universe.
India’s radio astronomy capabilities form a strategic ecosystem: uGMRT (metre waves, Pune), Ooty Radio Telescope (530 MHz, Tamil Nadu), and participation in the Square Kilometre Array (SKA) project. For GS-III, understand how these investments serve dual purposes: (1) Pure science — answering fundamental cosmological questions; (2) Technology development — radio frequency engineering, signal processing, and data analysis techniques with defence and communications applications. India’s radio astronomy instrumentation expertise has been cited as a key input for indigenous radar systems and electronic warfare capabilities.
SFDR Missile: Air-Breathing Propulsion for Next-Generation Air Defence
The Solid Fuel Ducted Ramjet (SFDR) missile technology, developed by DRDO, represents a critical advancement in India’s missile defence capabilities. The SFDR was jointly developed by three DRDO laboratories: Defence Research and Development Laboratory (DRDL), Research Centre Imarat (RCI), and High Energy Materials Research Laboratory (HEMRL).
The defining feature of SFDR technology is its air-breathing propulsion. Unlike conventional solid or liquid-fuelled missiles that carry both fuel and oxidiser, an air-breathing missile uses atmospheric oxygen for combustion, eliminating the need for an onboard oxidiser. This has three transformative advantages:
1. Extended range: By not carrying oxidiser, the missile saves weight, which translates to greater fuel capacity and extended range.
2. Sustained supersonic flight: The ramjet sustainer provides continuous thrust, maintaining supersonic speeds (Mach 1 to Mach 5) throughout the flight envelope, unlike conventional missiles that decelerate after the booster phase.
3. Terminal manoeuvrability: The sustained thrust allows the missile to execute high-G terminal manoeuvres, making it extremely difficult for targets to evade.
The SFDR programme exemplifies India’s defence indigenisation strategy. For GS-III, analyse this within the Atmanirbhar Bharat defence framework: (1) Only a handful of countries (USA, Russia, France, China, UK) possess air-breathing missile technology; (2) The inter-laboratory collaboration model (DRDL for systems, RCI for guidance, HEMRL for propellants) demonstrates the DRDO ecosystem approach; (3) The technology has applications across multiple platforms — air-to-air, surface-to-air, and anti-ship missiles. Consider the strategic implications of India joining the exclusive club of air-breathing missile nations for its deterrence calculus vis-a-vis regional adversaries.
Intrusion Detection System (IDS) for Indian Railways: Fibre-Optic Sensing at Scale
The deployment of an Intrusion Detection System (IDS) for Indian Railways at a cost of Rs 208 crore, covering 1,158 km of track, represents one of the world’s largest deployments of Distributed Acoustic Sensing (DAS) technology for railway safety. The system utilises Rayleigh scattering in optical fibres to detect vibrations and disturbances along the railway track in real-time.
– Cost: Rs 208 Crore
– Coverage: 1,158 km of track
– Technology: Distributed Acoustic Sensing (DAS)
– Physics: Rayleigh scattering in optical fibres
– Key application: Elephant detection near tracks
– Real-time monitoring: Continuous 24/7 surveillance
Distributed Acoustic Sensing works by sending laser pulses through an optical fibre and analysing the backscattered light caused by Rayleigh scattering — the elastic scattering of light by inhomogeneities in the fibre structure. When external vibrations (from footsteps, vehicles, animals, or earth movements) disturb the fibre, the scattered light pattern changes. By analysing these changes, the system can detect, classify, and localise disturbances with metre-level precision along the entire length of the fibre.
One of the most compelling applications is elephant detection. India loses approximately 20-25 elephants annually to train collisions, with Assam, West Bengal, Kerala, and Odisha being the most affected states. The IDS can detect elephants approaching the track from several hundred metres away, providing sufficient time for train drivers to be alerted and reduce speed. This represents a technology-driven solution to a conservation challenge that has resisted conventional mitigation measures like speed restrictions and solar fencing.
G — Giant radio galaxy J1007+3540 (uGMRT, 30 antennas, NCRA-TIFR)
R — Ramjet SFDR (air-breathing, DRDL + RCI + HEMRL)
I — IDS Railways (Rs 208 Cr, 1,158 km, DAS)
D — Detection via Rayleigh scattering (elephant safety)
Source: UPSC Essentials, The Indian Express — March 2026
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