National Large Solar Telescope & Optical-NIR Telescope

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In the Union Budget, the Government of India sanctioned the establishment of two major astronomical facilities — the National Large Solar Telescope (NLST) and the National Large Optical–Near Infrared Telescope (NLOT).

These projects aim to strengthen India’s capabilities in solar physics, space weather studies, and deep-space astronomy, placing the country among leading global centres of astronomical research.

Why in News?

The Union Budget approved two mega telescope projects.
NLST will focus on solar studies, while NLOT will study the universe’s origins.
Both facilities will be located in high-altitude regions of Ladakh.
They will enhance India’s space science and astrophysics ecosystem.

National Large Solar Telescope (NLST)

Location and Design

Aperture: 2 metres
Location: Merak region near Pangong Tso Lake, Ladakh
Altitude Advantage: Thin atmosphere and low turbulence
Wavelengths: Visible and near-infrared

The high-altitude and dry climate of Ladakh makes Merak ideal for high-resolution solar observations.

Purpose and Scientific Objectives

The NLST is designed to study the Sun in unprecedented detail.

Key Focus Areas

Solar magnetism and sunspots
Solar flares and coronal mass ejections
Fundamental solar dynamics
Space weather processes
Impact on satellites and space missions

It will help scientists predict solar storms that can disrupt communication systems, navigation satellites, and power grids.

Place in India’s Solar Research Network

NLST will become India’s third ground-based solar observatory, after:

Kodaikanal Solar Observatory (Established: 1899)
Udaipur Solar Observatory (Established: 1975)

With NLST, India will gain modern, high-resolution solar observation capabilities.

National Large Optical–Near Infrared Telescope (NLOT)

Location and Structure

Aperture: 13.7 metres
Location: Hanle, Ladakh
Mirror Type: Segmented mirror
Number of Segments: 90 hexagonal mirrors

All segments together act as a single large mirror, enabling high light-collecting power.

Working Principle: Segmented Mirror Technology

In a segmented-mirror telescope:

A large primary mirror is divided into smaller segments.
Each segment is precisely aligned.
All mirrors work together as one surface.

This design allows construction of very large telescopes that are otherwise impractical as single mirrors.

Scientific Objectives

The NLOT will enable frontier research in astrophysics and cosmology.

Major Research Areas

Detection and study of exoplanets
Stellar life cycles and evolution
Formation of galaxies
Supernova explosions
Dark matter and dark energy
Origins of the universe

It will be among the world’s largest optical–infrared telescopes.

Strategic and Scientific Significance of NSLT and NLOT

1. Strengthening Space Research

Supports India’s satellite and launch programmes
Improves space weather forecasting
Enhances planetary science

2. Global Scientific Collaboration

Attracts international researchers
Enables joint projects
Enhances India’s soft power in science

3. Technological Development

Advances optics, sensors, and precision engineering
Boosts indigenous scientific manufacturing

4. Regional Development

Promotes Ladakh as a science hub
Creates skilled employment
Improves research infrastructure

Challenges for the Project

Despite their potential, both projects face challenges:

Harsh climatic conditions
High construction and maintenance costs
Logistical difficulties in high-altitude regions
Need for highly skilled manpower

Addressing these issues requires sustained policy and financial support.

Conclusion

The establishment of the National Large Solar Telescope and the National Large Optical–Near Infrared Telescope marks a decisive step in India’s scientific advancement. By strengthening solar physics, space weather monitoring, and cosmological research, these facilities will place India among leading nations in astronomy. They also reflect the government’s commitment to promoting high-end scientific infrastructure and innovation.

Summary

The National Large Solar Telescope and the National Large Optical–Near Infrared Telescope represent a major investment in India’s scientific infrastructure. While NLST will deepen understanding of solar activity and space weather, NLOT will enable frontier research in exoplanets and cosmology. Together, they will strengthen India’s position in global astronomy and space research.