[Answered] What is Lagrange point? Discuss objectives and importance of ISRO’S Aditya-L1 mission.

The Indian Space Research Organisation (ISRO) is planning to launch the first solar mission, Aditya-L1. Aditya-L1 mission is aimed at studying the Sun from an orbit around the Sun-Earth Lagrangian point 1 (L1) which is about 1.5 million kilometres from the Earth.

What are Lagrange points?

Lagrange Points are are positions where the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them.

• These are positions in space where the gravitational forces of a two body system like the Sun and the Earth produce enhanced regions of attraction and repulsion.
• These can be used by spacecraft to reduce fuel consumption needed to remain in position.
• There are five special points where a small mass can orbit in a constant pattern with two larger masses. Of the five Lagrange points, three are unstable and two are stable. The unstable Lagrange points are L1, L2 and L3 and the stable Lagrange points L4 and L5.
• The L1 point of the Earth-Sun system provide an uninterrupted view of the sun. In order to get the continuous view of the sun Aditya- L1 satellite will be placed in the halo orbit around the Lagrangian point 1 (L1) of the sun-earth system.

Objectives of Aditya-L1 mission: Aditya-L1 is the India’s first dedicated scientific mission, which aims to send a satellite to study sun’s chromosphere.

1. The objective of the mission is to study the dynamic nature of the sun’s outer most layers, the corona and the chromosphere.
2. To collect data about Coronal Mass Ejections (CME).
3. It will study on origin of solar storms and their path through the interplanetary space from the Sun to the Earth.
4. The studies will also focus on collection of information for space weather prediction.

Importance of Aditya-L1 mission:

1. This mission will present clear picture of sun’s chromosphere, which in turn will help us to understand the concept of sun’s corona visible during solar eclipse.
2. It will help to study the discharging of charged particles into space which affect the environment there called solar wind.
3. The data from Aditya mission will be helpful in discriminating different models for the origin of solar storms and also for constraining how the storms evolve and what path they take through the interplanetary space from the Sun to the Earth.
4. It will help in measuring solar irradiance variations.
5. It will help in study the variation of solar wind properties as well as its distribution and characteristics.       
6. It will help in studying the heating mechanism of the solar corona.
7. It will further enhance ISRO’s capabilities for more challenging missions.

This project provides an opportunity to scientists from multiple institutions within the country to participate in space based observations. Aditya-L1 project will enable a comprehensive understanding of the different processes of the sun. The challenge before ISRO is placing the satellite at L1 point where it will send Indian spacecraft for the first time.