In News:

The Union Budget 2026 has approved the establishment of two major telescope facilities in Ladakh—the National Large Solar Telescope (NLST) and the National Large Optical–Near Infrared Telescope (NLOT) along with the upgradation of the existing Himalayan Chandra Telescope (HCT).

Operated by the Indian Institute of Astrophysics (IIA), these projects aim to strengthen India’s capacity in frontline space science, solar physics, and cosmology while consolidating Ladakh’s status as the country’s premier astronomy hub.

Ladakh, particularly the Hanle region located at over 4,000 metres above sea level, offers exceptional observing conditions like high altitude, cold desert climate, minimal atmospheric water vapour, and extremely low light pollution. The presence of the Hanle Dark Sky Reserve, India’s first, ensures protection of natural night skies through strict lighting regulations. These factors enable year-round observations, unlike many mainland observatories affected by monsoons, thereby maximizing scientific output.

National Large Solar Telescope (NLST)

The NLST, a 2-metre aperture solar telescope, will be installed near Pangong Tso in Merak. Operating in visible and near-infrared wavelengths, it is expected to be completed within 5–6 years. With a spatial resolution of about 50 km and millisecond-level temporal resolution, NLST will enable high-precision studies of solar dynamics, magnetic fields, flares, and coronal mass ejections.

Understanding these processes is crucial for space-weather forecasting, as solar disturbances can disrupt satellites, communication networks, power grids, and space missions. NLST will complement India’s space-based solar mission, Aditya-L1 (launched in 2023), and join the historic Kodaikanal Solar Observatory (1899) and Udaipur Solar Observatory (1975) as India’s third ground-based solar facility. Strategically, it fills a longitudinal gap in global solar observation networks, enhancing India’s contribution to heliophysics.

National Large Optical–Near Infrared Telescope (NLOT)

The NLOT, to be located in Hanle, will be a 13.7-metre class segmented-mirror telescope, placing it among the world’s largest optical–infrared observatories. Its primary mirror will consist of 90 hexagonal segments functioning as a unified optical surface, enabling collection of faint cosmic light with high precision.

Projected to be operational within a decade, NLOT will facilitate cutting-edge research in exoplanets, stellar and galactic evolution, supernovae, and the origins of the universe. Its infrared capability allows observation of distant and dust-obscured objects, critical for studying early cosmic epochs.

India’s technical expertise gained from its participation in the Thirty Meter Telescope (TMT) project where it contributes mirror segments and segment-support assemblies will aid in constructing NLOT’s advanced optical systems. Importantly, domestic ownership ensures greater observation time for Indian scientists, overcoming the limitations of competitive international access.

Upgradation of the Himalayan Chandra Telescope (HCT)

Operational since 2001, the 2-metre HCT has contributed significantly to transient astronomy, including supernova studies. The planned upgrade to a 3.7-metre segmented mirror system will enhance sensitivity and expand its optical–infrared capabilities. The upgraded HCT will work synergistically with global facilities such as LIGO-India (gravitational-wave observatory in Maharashtra) and the Square Kilometre Array (radio telescope in Australia and South Africa), enabling multi-messenger astronomy.

Significance

Together, NLST, NLOT, and the upgraded HCT represent a transformative investment in India’s scientific infrastructure. They strengthen India’s strategic autonomy in high-end research, support capacity building in precision engineering, and position the country and the Global South more prominently in global astronomy. Complemented by a new COSMOS planetarium in Andhra Pradesh for outreach and education, the initiative reflects a comprehensive vision that integrates research excellence, technological self-reliance, and public scientific engagement.