Aditya-L1 Mission (2023): India's First Solar Observatory in Space

• Aditya-L1 is India’s first space-based solar observatory designed to study the Sun from space. 
• It was developed by ISRO (Indian Space Research Organisation) and launched in September 2023. 
• The mission is placed in a halo orbit around the L1 Lagrange Point, which is about 1.5 million km from Earth.
• Unlike ground-based solar telescopes, Aditya-L1 can continuously observe the Sun without atmospheric interference or eclipses.

Why is the Sun Important?

• The Sun affects everything on Earth, from climate to communication systems. 
• It emits solar flares and coronal mass ejections (CMEs) that can disrupt satellites, GPS, and power grids. 
• Understanding the Sun’s behaviour helps us predict space weather and protect our technology.

Scientific Objectives of Aditya-L1

The mission aims to:

• Study the Sun’s upper atmosphere (Corona & Chromosphere).
• Observe solar flares and CMEs, which impact space weather.
• Analyze solar wind particles that travel through space and affect Earth.
• Understand the Sun’s magnetic field and how it influences solar storms.

How Does Aditya-L1 Work? 

• To study the Sun, Aditya-L1 carries 7 advanced scientific instruments (payloads):
  • VELC (Visible Emission Line Coronagraph) – Studies the Sun’s outer atmosphere (Corona).
  • SUIT (Solar Ultraviolet Imaging Telescope) – Takes ultraviolet (UV) images of the Sun.
  • ASPEX (Aditya Solar Wind Particle Experiment) – Measures solar wind particles.
  • PAPA (Plasma Analyzer Package for Aditya) – Analyzes the energy of solar particles.
  • HEL1OS (High Energy L1 Orbiting X-ray Spectrometer) – Observes X-ray radiation from solar flares.
  • Magnetometer – Measures the Sun’s magnetic fields.

What is a Halo Orbit?

• Aditya-L1 is placed in a halo orbit around the L1 Lagrange Point.
• A halo orbit is a stable 3D orbit around a Lagrange point (L1, L2, or L3).
• It allows the spacecraft to continuously observe the Sun without Earth blocking the view.
• Requires very little fuel to stay in position.

What are Lagrange Points?

• Lagrange Points are special positions in space where the gravitational forces of two large objects (like the Earth and Sun) balance with a satellite’s motion.
• There are 5 Lagrange points (L1 - L5) in any two-body system (e.g., Earth-Sun).
  • L1: Best for solar observation (Aditya-L1, SOHO).
  • L2: Used for deep space telescopes (James Webb, Gaia).
  • L3: Positioned behind the Sun, rarely used.
  • L4 & L5: Stable zones with low fuel consumption (Trojan asteroids are found here).

Other Major Solar Missions

Why is Aditya-L1 Important?

• First Indian mission dedicated to studying the Sun.
• Continuous solar observation from space (unlike ground telescopes).
• Helps predict solar storms and protect satellites & power grids.
• Boosts India's space weather research capabilities.