Aditya-L1 Mission: Sun Secrets, Launch Cost & Budget Sept ’23 | UPSC

The Aditya-L1 Mission, often referred to as India’s ambitious sun-watching mission, has been a topic of considerable interest. This mission represents a significant leap in India’s space exploration efforts, aiming to unravel the enigmatic secrets of our nearest star, the Sun.

In this article, you will discover details about the Aditya-L1 Mission, including its objectives, significance, and pertinence to UPSC aspirants.

Aditya-L1 Mission

Aditya-L1 is India’s first dedicated mission to study the Sun. It aims to gather crucial data about the Sun’s various layers and activities to better understand its behavior and its influence on Earth.

Now, let us know some important information about the mission:

  • Orbital Position: The spacecraft will be placed in a unique orbit known as a halo orbit around a region called Lagrange point 1 (L1) in the Sun-Earth system. L1 is located about 1.5 million kilometers away from Earth in the direction of the Sun.
  • Continuous Sun Observation: The halo orbit at L1 provides an unparalleled advantage – it allows continuous, uninterrupted observation of the Sun without any interruptions like eclipses. This offers real-time monitoring of solar activities and their impact on space weather.
  • Payloads: Aditya-L1 carries seven specialized scientific instruments or payloads. These payloads include instruments to observe the Sun’s visible surface (photosphere), and its outermost layer (corona), and to measure various solar phenomena like magnetic fields and particles.
  • Launch Vehicle: The mission will be launched using a Polar Satellite Launch Vehicle (PSLV), a reliable launch vehicle developed by the Indian Space Research Organisation (ISRO). ISRO’s extensive experience with PSLV launches makes it well-suited for missions like Aditya-L1.
  • Naming: The Aditya-L1 satellite is named after the Sun God. This chosen name underscores the deep connection between the mission and the powerful entity that fuels our solar system.
Aditya L1 Mission UPSC Launch Date Time Update News, Full form

Objectives of Aditya-L1 Mission

Certainly, here are the key objectives of the Aditya-L1 mission:

  • Study the Sun’s Upper Atmosphere: Understand how the outer layers of the Sun, like the chromosphere and corona, behave.
  • Explore Solar Heating: Investigate how these outer layers are heated, learn about the plasma, and understand processes like coronal mass ejections and solar flares.
  • Collect Data from Space: Gather information directly from space about particles and plasma originating from the Sun.
  • Unlock Solar Corona Secrets: Unravel the mysteries behind the Sun’s corona and how it gets heated.
  • Measure Plasma Properties: Use diagnostics to figure out things like temperature, velocity, and density in the Sun’s outer layers.
  • Study Coronal Mass Ejections: Examine the formation, movement, and origins of solar eruptions known as Coronal Mass Ejections.
  • Understand Solar Eruptions: Discover the step-by-step processes leading to solar eruptions across different layers of the Sun.
  • Analyze Solar Magnetic Fields: Investigate the magnetic field patterns and strength in the Sun’s outer atmosphere.
  • Examine Space Weather Causes: Study what causes space weather events by understanding the solar wind’s origin, composition, and behavior.

Total Cost of Mission: Aditya-L1

Aditya L1’s financial commitment to solar exploration stands at a significant figure: 825 crore 48 lakh 25 thousand Indian rupees (INR 8,25,48,25,000.00), equivalent to approximately $100 million.

Aditya-L1 Mission Launch Date

The scheduled launch date for the ADITYA L1 Mission is September 2, 2023. This mission marks India’s first dedicated effort to observe the Sun and is set to be launched aboard a PSLV-XL launch vehicle.

Originally, the Aditya L1 mission was slated for launch in the early 2020s. However, due to various factors, including the disruptive impact of the COVID-19 pandemic, the launch timeline was postponed.

Aditya-L1 Mission UPSC

According to ISRO Chairman S Somanath, the Aditya L1 satellite, which is designed for solar observations, is now scheduled to be launched on 2nd Sep 2023.

The satellite, which was developed at Bengaluru’s U R Rao Satellite Centre (URSC), has already been transported to SDSC-SHAR in Sriharikota, where it will embark on its mission to explore the Sun.

Lagrange Points

Lagrange points, named after the French mathematician Joseph-Louis Lagrange, are specific locations in space where the gravitational forces of two large objects, such as the Earth and the Moon or the Earth and the Sun, create a stable equilibrium.

Let us understand with an example:

Imagine you have two objects in space, like the Earth and the Moon. They both have gravity, which pulls other objects towards them.

Lagrange points are specific places in space where the gravity from the Earth and the Moon (or any two objects) creates a kind of “balance.” At these points, the pull of gravity from both objects is just right, so a smaller object can stay in one place without using a lot of fuel to stay there.

Lagrange Point Aditya L1 Mission UPSC
Lagrange Points

Five Lagrange points

There are five of these special points around the Earth and the Sun, often denoted as L1, L2, L3, L4, and L5, and each has its own unique features:

I. L1 (Lagrange Point 1)

  • Location: Between the Earth and the Sun.
  • Use: Ideal for solar observatories and space weather monitoring.
  • Example: The Solar and Heliospheric Observatory (SOHO) is positioned at L1 and continuously observes the Sun, providing valuable data about solar activities and space weather.

II. L2 (Lagrange Point 2)

  • Location: On the opposite side of the Earth from the Sun.
  • Use: Valuable for space telescopes observing distant celestial objects.
  • Example: The James Webb Space Telescope (JWST) is planned to be positioned at L2. It will study the universe in infrared wavelengths, providing insights into distant galaxies, stars, and planets.

III. L3 (Lagrange Point 3)

  • Location: Positioned on the opposite side of the Sun from the Earth.
  • Use: Less commonly used and less stable.
  • Example: L3 is not commonly utilized for missions, and there are no well-known missions currently positioned there.

IV. L4 and L5 (Lagrange Points 4 & 5)

  • Location: Form equilateral triangles with the Earth and the Moon (or other massive bodies).
  • Use: Associated with groups of asteroids and potential future space missions.
  • Example: The upcoming Lucy mission by NASA will visit multiple asteroids in Jupiter’s orbit, including Trojans located at Jupiter’s L4 and L5 points.

It’s important to note that objects placed at Lagrange points do not orbit the Lagrange points themselves. Instead, they orbit the larger celestial bodies (like the Earth or the Sun) while remaining in a fixed position relative to those bodies due to the gravitational balance at the Lagrange point.

This stability is a valuable feature for various space missions and scientific observations, offering a unique perspective on our solar system and beyond.

Aditya-L1’s Payloads

Here’s a simplified explanation of the payloads and scientific instruments on board the Aditya-L1 mission:

Payloads of Aditya-l1 mission UPSC
Payloads of Aditya-l1 mission UPSC
  1. VELC (Visible Emission Line Coronagraph): This tool will take pictures and analyze the Sun’s outer atmosphere (corona), observing events like coronal mass ejections.
  2. SUIT (Solar Ultraviolet Imaging Telescope): SUIT captures images of different parts of the Sun and measures how much sunlight it emits, helping scientists understand variations in solar energy.
  3. SoLEXS (Solar Low Energy X-ray Spectrometer) and HEL1OS (High Energy L1 Orbiting X-ray Spectrometer): These instruments study X-rays coming from the Sun, especially during flares, giving insights into its X-ray emissions.
  4. ASPEX (Aditya Solar Wind Particle Experiment) and PAPA (Plasma Analyser Package For Aditya): These tools examine electrons, protons, and ions in the solar wind, helping us understand the Sun’s particle environment.
  5. Advanced Tri-axial High-Resolution Digital Magnetometers: This payload studies the magnetic field between the Earth and the Sun at L1, providing important data about solar magnetic behavior.

Polar Satellite Launch Vehicle (PSLV)

  • Indigenous Development: The PSLV stands as a third-generation launch vehicle that has been meticulously designed and developed within India by ISRO.
  • Exceptional Reliability: Globally recognized as one of the most dependable and versatile launch vehicles, the PSLV boasts an impressive track record of more than 50 consecutive successful missions.
  • Four-Stage Design: The PSLV’s architecture encompasses four stages, incorporating distinctive attributes such as the incorporation of liquid stages.
  • Payload Capacity: The PSLV demonstrates its prowess by effectively transporting payloads of up to 1,750 kg to the Sun-Synchronous Polar Orbits (SSPO) situated at an altitude of 600 km. Furthermore, it can manage payloads of 1,425 kg to both Geosynchronous and Geostationary orbits.
  • Stage Configuration:
    • The foundational first stage gains its propulsive energy from the S139 solid rocket motor and is fortified by six solid strap-on boosters.
    • Employing the Vikas engine, developed by the Liquid Propulsion Systems Centre, the second stage integrates an Earth-storable liquid rocket engine.
    • The third stage utilizes a solid rocket motor to deliver heightened thrust subsequent to the atmospheric phase of the launch.
    • The topmost fourth stage of the PSLV is outfitted with two Earth-storable liquid engines.

The Sun

The Sun, at the heart of our solar system, is a colossal sphere of searing hot plasma, responsible for providing light, heat, and the vital energy essential for life on Earth. Its sheer magnitude and the prolific energy it radiates have intrigued astronomers and scientists for centuries.

Structure & Composition

  • Core: Deep within the Sun resides the core, where the spectacular nuclear fusion reactions occur. Hydrogen atoms join together to form helium, releasing a tremendous amount of energy in the process.
  • Radiative Zone: Encompassing the core, the radiative zone facilitates the transmission of energy through photons, generated during the core’s fusion reactions.
  • Convection Zone: Situated above the radiative zone, the convection zone is a dynamic layer where hot plasma moves, transferring heat through large cells of rising and sinking material. These convective movements create the granulated appearance observed on the Sun’s surface.
  • Photosphere: The Sun’s visible surface, the photosphere, is where most of its visible light emanates. Marked by sunspots and granules, it showcases intricate magnetic activities.
  • Chromosphere: Beyond the photosphere lies the chromosphere, which emits a reddish hue during solar eclipses, owing to hydrogen emissions.
  • Corona: Extending millions of kilometers into space, the outermost layer, the corona, appears as a radiant halo of plasma during solar eclipses. Remarkably, the corona boasts a temperature significantly higher than the Sun’s surface, a phenomenon still under scientific scrutiny, known as the coronal heating problem.

Solar Energy & Fusion

  • Nuclear Fusion: The Sun’s awe-inspiring energy output is a result of nuclear fusion. This process involves the fusion of hydrogen nuclei to create helium, generating energy in the form of both light and heat.
  • Energy Transport: Energy originating in the core embarks on a journey through the radiative and convective zones before finally reaching the photosphere, from where it is radiated out into the depths of space.

Solar Activities & Phenomena of Sun

  • Sunspots: Darkened patches on the photosphere are attributed to intense magnetic activity. These regions exhibit lower temperatures compared to their surroundings due to magnetic fields impeding convection.
  • Solar Flares: The Sun occasionally experiences explosive bursts of energy and radiation, known as solar flares, originating from the release of magnetic energy within its atmosphere. These flares can impact Earth’s space environment and communication systems.
  • Coronal Mass Ejections (CMEs): Massive eruptions of solar plasma and magnetic fields into space, termed coronal mass ejections, have the potential to trigger geomagnetic storms on Earth, affecting power grids and satellites.
  • Solar Wind: The Sun perpetually emits a stream of charged particles known as solar wind, which exerts a significant influence on the space environment, including the magnetic fields of planets such as Earth.

Must Read: Chandrayaan-3 Mission


The Aditya-L1 Mission stands as a testament to India’s commitment to advancing its scientific knowledge and technological capabilities in the field of space exploration.

For UPSC aspirants, staying informed about such missions is not only a matter of current affairs but also a demonstration of an awareness of India’s role in global science, diplomacy, and the emerging space economy.

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