Aditya-L1 Mission

Objective:

To provide a greater advantage in observing solar activities and their effect on space weather in real-time.
A satellite has the major advantage of continuously viewing the Sun without any occultation/eclipses.
To understand the drivers for space weather (origin, composition and dynamics of solar wind), and identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.
It will help in studying the temperature, velocity and density of the corona, understand the processes that result in heating of the corona and acceleration of the solar wind, aid studies on drivers of space weather, measure the magnetic field of corona and study the development and origin of coronal mass ejection.

Where in space?

The spacecraft shall be placed in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system, which is about 1.5 million km from the Earth.
Using the special vantage point L1, four payloads directly view the Sun and the remaining three payloads carry out in-situ studies of particles and fields at the Lagrange point L1, thus providing important scientific studies of the propagatory effect of solar dynamics in the interplanetary medium.
The spacecraft carries seven payloads to observe the photosphere, chromosphere and the outermost layers of the Sun (the corona) using electromagnetic and particle and magnetic field detectors.

Payloads:

The 7 payloads include:

What are Lagrangian Points?

Lagrangian points, also known as Lagrange points or libration points, are specific locations in space where the gravitational forces of two large bodies, such as a planet and its moon or a planet and the Sun, produce enhanced regions of gravitational equilibrium.
In these points, the gravitational pull from the two bodies creates a stable or quasi-stable region where a third, smaller object can maintain a relatively constant position relative to the larger bodies.
There are five primary Lagrangian points, labeled L1 through L5, in a Sun-Earth system.
L1 (Lagrange Point 1):

It was found by mathematician Joseph Louis Lagrange.
It is located about 1.5 million kilometers inside Earth’s orbit, between the Sun and the Earth.
The L1 point of the Earth-Sun system gives a clear view of the sun all the time, without any occultation/ eclipses.
Once the Aditya L1 mission reaches the L1 Lagrange point, it will be injected to a halo orbit. A halo orbit is a type of orbit that allows the satellite to remain in a stable position between the Earth and the Sun.

Other Missions to the Sun:

NASA’s Parker Solar Probe: Aims to trace how energy and heat move through the Sun’s corona and to study the source of the solar wind’s acceleration.
- It is part of NASA’s ‘Living With a Star’ programme that explores different aspects of the Sun-Earth system.
Helios 2 Solar Probe: The earlier Helios 2 solar probe, a joint venture between NASA and space agency of erstwhile West Germany, went within 43 million km of the Sun’s surface in 1976.
Solar Orbiter: A joint mission between the ESA and NASA to collect data that will help answer a central question of heliophysics like how the Sun creates and controls the constantly changing space environment throughout the solar system.
Other Active Spacecraft Monitoring the Sun: Advanced Composition Explorer (ACE), Interface Region Imaging Spectrograph (IRIS), WIND, Hinode, the Solar Dynamics Observatory, and Solar Terrestrial Relations Observatory (STEREO).