Adithya L1: ISRO's Quest to Understand the Sun

About Adithya - L1

                     The first space-based Indian mission to study the Sun will be called Aditya L1. The spacecraft will be positioned in a halo orbit around the Sun-Earth system's Lagrange point 1, or L1, which is located approximately 1.5 million km from Earth. The main benefit of having a satellite in the halo orbit around the L1 point is being able to continuously see the Sun without any occultation or eclipses. This will provide us a better opportunity to watch the solar activity and how it affects the space weather in real time. The spacecraft is equipped with seven payloads that use electromagnetic, particle, and magnetic field detectors to study the photosphere, chromosphere, and the Sun's outermost layers (the corona). Four payloads use the unique vantage point L1 to observe the Sun directly, while the remaining three payloads conduct in-situ particle and field studies at the Lagrange point L1. This allows for significant scientific research on the propagation of solar dynamics in the interplanetary medium.

                    In order to comprehend the issue of coronal heating, coronal mass ejection, pre-flare and flare activities and their features, dynamics of space weather, propagation of particle and fields, etc., the Aditya L1 payloads are expected to offer the most important information.

Why We Need to Study the Sun ?

1. The sun can be studied in considerably greater detail than other stars since it is the closest.

2. Stars: We can discover a lot more about stars in our Milky Way galaxy and other galaxies by observing the sun.

3. The sun is an extremely dynamic star that spans a vast area beyond what we can currently observe. It displays a variety of eruptive events and unleashes a tremendous amount of energy into the solar system. Such violent solar occurrences could generate a variety of perturbations in the space environment close to the earth if they are directed at the planet. 

4. Numerous spacecraft and communication systems are vulnerable to these disruptions, therefore early notification of such occurrences is crucial for taking preventative action. In addition to these risks, an astronaut would be in danger if they were exposed directly to such explosive events.

5. On the sun, there are several severe thermal and magnetic phenomena. As a result, the sun serves as a useful natural laboratory for understanding processes that cannot be directly investigated in a lab. 

Uniqueness Of The Mission: Adithya -L1

1. First time spatially resolved solar disk in the near UV band. 

  

2. CME dynamics close to the solar disk (~ from 1.05 solar radius) and thereby providing information         in the acceleration regime of CME which is not observed consistently. 

3. On-board intelligence to detect CMEs and solar flares for optimised observations and data volume. 

4.  Directional and energy anisotropy of solar wind using multi-direction observations.

Adithya - L1  mission overview 

Lagrange Points 

                      The Lagrange Points are the locations in space where a small object, if placed there, tends to stay in a two-body gravitational system. Spacecraft can exploit these locations in space for two-body systems like the Sun and Earth to stay in place while using less fuel.

                    Technically, the gravitational pull of the two huge things at Lagrange point equals the centripetal force required for a tiny item to move in the same direction as them. There are a total of five Lagrange points for two-body gravitational systems, identified as L1, L2, L3, L4, and L5. The figure displays the Sun-Earth system's Lagrange points. The Sun-Earth line is where the Lagrange point L1 is located. L1 is located around 1% of the Earth-Sun distance away from Earth. 

Science Objectives: Adithya - L1

The major objectives of Adithya - L1 mission are :

1. Study of solar upper atmospheric (Chromosphere and corona) dynamics.

2. Study of chromospheric an coronal heating, Physics ionized plasma, initiation of the coronal mass ejections, and flares.

3. Observe the in-situ particle and plasma environment providing data for the study of particle dynamics from the sun.

4. Physics of solar corona and it's heating mechanism.

5.  Diagnostics of the coronal and coronal loops plasma: temperature, velocity, density.

6. Development, dynamics and origin of CME,s

7. Identify the sequence of processes that occur at multiple layers(chromosphere, base and extended corona) which eventually leads to solar eruptive events.

8. Magnetic field topology and magnetic field measurements in the solar corona.

9. Drivers for space weather(origin, composition and dynamics of solar wind).

Adithya - L1 Payloads :

                    The Aditya-L1 spacecraft's instruments are set up to primarily observe the chromosphere and corona of the sun. At L1, in-situ instruments will monitor the immediate environment. There are a total of seven payloads aboard, four of which perform solar remote sensing and three of which perform in-situ observations.

Payloads along with their major capability of scientific investigation:

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