top of page

Aditya L1: India's Eye on the Sun and Why It Matters

Aditya L1

Launched today, i.e., on September 2, 2023, the Aditya L1 spacecraft is not merely another milestone in India's rich history of space exploration; it is a giant leap forward. Orchestrated by the Indian Space Research Organisation (ISRO), this highly sophisticated mission has been designed with the explicit aim of expanding human knowledge about our closest star, the Sun. Aditya L1 specifically focuses on probing various mysteries surrounding the Sun's outermost layer, known as the corona.

This mission propels India into an exclusive league of nations that have undertaken dedicated solar missions, showcasing the country's growing prowess in space science and technology. The research and data expected from Aditya L1 will not only augment our fundamental understanding of solar physics but are also poised to have practical implications, ranging from space weather prediction to safeguarding Earth's satellite and communication systems.

Why Care About the Sun?

Aditya L1 is not going on a vacation; it's going to work. Here's what it's up to:

  • Study the Corona: That's the Sun's outermost layer, not the beer! Scientists want to know why it's hotter than the Sun's surface.

  • Space Weather: Solar flares and stuff like that can mess with satellites and even power grids on Earth.

  • Climate Impact: Believe it or not, the Sun's activity can affect our climate too.

The Special Orbit of Aditya L1

Lagrange Point

The L1 Lagrange Point

The spacecraft will be positioned at the L1 Lagrange point, approximately 1.5 million km away from Earth. The L1 point is one of five Lagrange points in the Sun-Earth system, which are locations where the gravitational forces of the Sun and Earth balance the orbital motion of a satellite.

This orbit is unique because it allows the spacecraft to stay in a stable position relative to the Sun and Earth, providing an uninterrupted view of the Sun for continuous data collection. This stability negates the need for frequent orbital adjustments, thereby saving fuel and extending the mission's lifespan.

Being at the L1 Lagrange point ensures that the spacecraft can consistently observe the same solar regions, a crucial requirement for studying time-dependent solar phenomena like solar flares and Coronal Mass Ejections (CMEs). It also allows for the constant monitoring of solar wind, aiding in the research of space weather's impact on Earth.

Comparing Aditya L1 with Previous Solar Missions

NASA's Parker Solar Probe
NASA's Parker Solar Probe

NASA's Parker Solar Probe

Launched in 2018, this mission aims to get closer to the Sun than any previous mission.


  • Parker Solar Probe orbits much closer to the Sun but for shorter observation windows.

  • It doesn't focus on continuous observation due to its elliptical orbit.


  • Both missions aim to study the corona and solar wind.

ESA's Solar Orbiter
ESA's Solar Orbiter

ESA's Solar Orbiter

Launched in 2020, this mission aims to provide close-up views of the Sun's polar regions.


  • Solar Orbiter will eventually tilt its orbit to observe the Sun's poles, while Aditya L1 stays at the L1 point.


  • Both aim to study the solar wind and its influence on the solar system.


SOHO (Solar and Heliospheric Observatory)

A joint mission by NASA and ESA, SOHO has been in operation since 1995 and also orbits around the L1 point.


  • Aditya L1 has a more modern set of instruments, allowing for a wider range of observations.


  • Both missions use the L1 point for stable, continuous observations of the Sun.


Solar Ultraviolet Imaging Telescope (SUIT)

This telescope will capture images of the Sun in multiple ultraviolet wavelengths. It aims to provide crucial data for understanding the solar photosphere and chromosphere, allowing researchers to examine how energy is transferred through these layers.

Visible Emission Line Coronagraph (VELC)

This instrument is designed to study the solar corona by capturing its images at visible wavelengths. VELC will offer insights into the diagnostics of the solar corona and help scientists understand the dynamics of Coronal Mass Ejections (CMEs) and their interactions with solar winds.

Solar Low-Energy X-ray Spectrometer (SoLEXS)

SoLEXS will monitor the soft X-rays emanated from solar flares. It will offer essential data for understanding the mechanisms behind solar flare occurrences and their energy release.

X-ray Spectrometer (XSM)

XSM will measure the Sun's X-ray spectrum, complementing the data collected by SoLEXS. It aims to determine the abundance of key elements in the Sun's atmosphere, which can provide a better understanding of the Sun's composition.

Plasma Analyser Package for Aditya (PAPA)

This package will measure solar wind properties like velocity, density, and temperature. PAPA will offer insights into how the solar wind interacts with Earth's magnetosphere and affects space weather conditions.

Solar Chromospheric Spectrometer (SolACES)

SolACES aims to study the properties of the solar chromosphere. It will help to understand the complex processes that occur in this layer, such as energy transfer mechanisms and magnetic activities.

Radio Occultation Experiment (ROC)

This experiment will measure the density distribution of the solar corona. ROC aims to develop new models for understanding coronal dynamics, including temperature and density variations.

Technical Specifications

The spacecraft employs a state-of-the-art Attitude and Orbit Control System (AOCS) and a Guidance, Navigation, and Control (GNC) system. These subsystems ensure the spacecraft can precisely orient itself for optimal data collection. The mission was sent into space aboard the PSLV-XL, one of ISRO's most advanced launch vehicles. Aditya L1 will be positioned at the L1 Lagrange point, about 1.5 million km from Earth. This location provides an unobstructed view of the Sun, allowing for continuous data collection.

The mission's data will be integral in enhancing our understanding of the Sun, from its most inner layers to its external impact on the solar system. It will be particularly vital for predicting solar storms that can affect satellite operations, power grids, and communication systems on Earth.

The Aditya L1 mission, with its diversified payload and ambitious objectives, solidifies India’s status as a key player in the world of solar and space research.

Cite this article as: Kumar, Yajur “Aditya L1: India's Eye on the Sun and Why It Matters” Space Navigators, 2 September 2023, ""


bottom of page