ADITYA-L1 : ISRO’s Upcoming Masterclass

5 min readOct 29, 2023


In the journey of life, failure is often considered a dreaded outcome, a symbol of defeat and disappointment. However, it is crucial to recognize that failure is not the end, rather it can be a stepping stone towards success. Our ISRO’s scientists were disappointed after the failure of the Chandrayaan 2 mission but at the same time, they were determined enough to study the south pole of the moon. Years later, India made history and became the first-ever country to land on the south pole of the moon. The successful Chandrayaan 3 mission, we all know about.

Now, it’s time to study the mighty sun. ISRO is working on a challenging mission to unlock the mysteries of the sun with ADITYA- L1.


ADITYA- L1, the mission to study the sun, is the first-ever Indian space-based observatory-class mission by ISRO. The spacecraft will be launched by PSLV-C57 and will be placed in the halo orbit of l1. The expectations from this mission are to get the most crucial information to understand the problems of coronal heating, Coronal Mass Ejection, pre-flare and flare activities, and their characteristics, dynamics of space weather, the study of the propagation of particles, fields in the interplanetary medium, etc.

Source: ISRO

Let’s include a few of the terms used in this blog in our dictionary for better understanding…

  1. Lagrange Point: It is the point in space where the gravitational pull of two large bodies equals the necessary centripetal force required for a small object to move with them. For a two-body system, there is a total of 5 Lagrange points namely, l1, l2, l3, l4 and l5. The Lagrange point l1, lies between the Sun and the Earth. Lagrange point has a unique characteristic in that it can be orbited by a halo orbit.

Source: ISRO

2. Halo Orbit: A halo orbit is a 3-D periodic orbit near the Lagrange points(l1, l2, l3). Orbits like these provide a line of sight.

Halo orbit, Source: Wikipedia

3. Coronal Heating: It relates to the question of why the temperature of the corona of the Sun is millions of kelvin, while that of the surface is only in thousands.

4. Coronal Mass Ejection: The ejection of the magnetic field and accompanying plasma mass from the Sun’s corona into the heliosphere is what we refer to as Coronal mass ejection.

5. Space Weather: It refers to the changing environmental conditions in space. The interaction of the Earth’s magnetic field with the high-energy photons from the Sun triggers a magnetic disturbance near the Earth. Also, there are flow of radiation and magnetic fields from the sun which affects the charged particle environment near the Earth and other planets.

Why study the Sun?

The sun is the largest object in the solar system and the nearest star to the Earth. Therefore, it can be studied in depth. It is a dynamic star in our solar system and extends much beyond what we see. Studying the sun can also help us in knowing about the other stars of the Milky Way.

The various thermal and magnetic phenomena of the sun are of extreme nature. Thus, the sun also provides an excellent natural laboratory to understand those phenomena that cannot be directly studied in the lab.

Along with these, the radiations from the sun, the high-energy photons and the magnetic field affect various spacecraft and communication systems.

Major objectives of the mission

  • Understanding the Coronal Heating and Solar Wind Acceleration.
  • Understanding initiation of Coronal Mass Ejection (CME), flares and near-earth space weather.
  • To understand the coupling and dynamics of the solar atmosphere.
  • To understand solar wind distribution and temperature anisotropy.

The uniqueness of the mission

  • First time spatially resolved solar disk in the near UV band.
  • CME dynamics close to the solar disk (~ from 1.05 solar radius) provide information on the acceleration regime of CME which is not observed consistently.
  • On-board intelligence to detect CMEs and solar flares for optimized observations and data volume.
  • Directional and energy anisotropy of solar wind using multi-direction observations.


Payload refers to the entity carried by the spacecraft in space to complete the objective and relay data back to Earth. The Aditya-L1 will carry seven payloads for the study of the sun.

SUIT Payload, Source: ISRO

Let’s learn about all the seven payloads in Aditya-L1:-

  1. VELC:- Visible Emission Line Coronagraph is designed to study solar corona and dynamics of coronal mass ejections
  2. SUIT:- Solar Ultra-violet Imaging Telescope to image the Solar Photosphere and Chromosphere in near Ultra-violet (UV) and, to measure the solar irradiance variations in near UV.
  3. SoLEXS and HEL10S:- Solar Low Energy X-ray Spectrometer and High Energy L1 Orbiting X-ray Spectrometer are designed to study the X-ray flares from the Sun over a wide X-ray energy range.
  4. ASPEX and PAPA:- The Aditya Solar Wind Particle Experiment and Plasma Analyzer Package for Aditya payloads are designed to study the solar wind and energetic ions, as well as their energy distribution.
  5. MAG:- Magnetometer payload is capable of measuring interplanetary magnetic fields at the L1 point.

Other Solar Probes

There have been over 20 missions by NASA and ESA since 1960 to study the sun. Some of them are listed below:-

  1. WIND:- Launched by NASA in November 1994 to study solar winds.
  2. SOHO:- Launched by NASA/ESA in May 1996 to investigate the sun’s core and corona.
  3. ACE:- Launched by NASA in August 1997 to have solar wind observations.
  4. DSCOVR:- Launched by NOAA in February 2015
  5. Parker Solar probe:- Launched by NASA in November 2018 to have a close-range solar coronal study.


The Aditya-L1 mission is a current ongoing mission by ISRO to study the Sun. The mission has the potential to significantly contribute to solving the mystery of why the Sun’s corona is so hot. It is a testament to the power of human ingenuity. Its quite exciting to see what the future holds for this mission and space exploration as a whole.

Abhinav Raj is the writer of this article. Views expressed and information provided belong solely to the author.




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