Aditya-L1: India’s First Solar Mission

After the success of Chandrayan-3, ISRO is ready to explore its horizon by launching the country’s first solar mission, Aditya-L1. The mission gets its name from the Sanskrit word Aditya, which translates to Sun in English, with L1 being the orbit point. This mission would be quite different from the Solar probe of NASA, Parker. The objective is not to study the sun while being very close to its surface but to form a halo orbit around the L1 Lagrange point, 1.5 km away from Earth between our gas giant and planet.

A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the Sun without any occultation/ eclipse. This will provide a greater advantage of observing solar activities continuously.

This will enable us to study our gas giant and solve mysteries surrounding it, for example, the coronal heating problem: the temperature of the corona gets hotter the more you move from it than what is below it. What this means is the temperature spikes up to 2 million Fahrenheit but about 1000 miles below is just 10,000 Fahrenheit.

Aditya spacecraft:

Aditya L1 is the first space-based observatory class Indian solar mission to study the Sun. It is installed with a total of 7 payloads in the satellite, there are both remote sensing payloads and in-situ experiments payloads. 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. The mission cost is estimated at around 400 Cr (INR).

(Credits: https://www.isro.gov.in/) 

The information about Payload is given below:

Remote sensing:-

1. Visible Emission Line Coronagraph (VELC): For spectroscopy

2. Solar Ultraviolet Imaging Telescope (SUIT): Imaging of Photosphere and Chromosphere

3. Solar Low Energy X-ray Spectrometer (SoLEXS): Soft X-ray spectrometer

4. High Energy L1 Orbiting X-ray Spectrometer(HEL1OS): Hard X-ray spectrometer

In-situ:-

1. Aditya Solar Wind Particle Experiment(ASPEX): Solar wind particle analyzer protons.

2. Plasma Analyser Package For Aditya (PAPA): Solar wind particle analyzer electrons.

3. Advanced Tri-axial High-Resolution Digital Magnetometers: In-situ magnetic field.

Mission Objectives:

1. Study of Solar upper atmospheric (chromosphere and corona) dynamics.

2. Study of chromospheric and coronal heating, physics of the partially 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 its heating mechanism.

These are some of the objectives that this mission will forward to accomplish.

Launch Information:

The mission is set to launch on 2 September 2023 using the PSLV rocket from Sathish Dhawan Space Centre SHAR (SDSC SHAR), Sriharikota. The flight path involves first forming a low earth orbit, later the orbit will be made more elliptical and then launched to the L1 Lagrange point using the onboard propulsion. It will take about four months to reach the L1 point which is outside the sphere of influence of the Earth’s gravitational field, where it will form a stable orbit, i.e. no need for propulsion to stay in the orbit.

(Credits: https://www.isro.gov.in/) 

Why this mission:

While reading the mission objectives, I’m sure it was difficult to understand what was happening or why it was happening. To make it simpler let me brief it up for you. The mission is more or less about making ourselves able to understand the space weather, You might recall from your 3rd-grade science classes, that the Sun is the source of both light and heat, while in higher studies we know the heat is caused by radiation emitted from the sun, and that sun has a magnetic field just like Earth. But here’s the catch, because of the coronal holes in the sun there are outbursts of plasma from the surface of the sun which we often call solar winds, They are composed of high-energy protons(positively charged particles). This happens as the plasma gets too hot even for the sun’s massive gravitational force to hold it together, so it pushes the magnetic energy out. These solar winds can travel up to 400 to 800 Km/s. During such events the nature of the magnetic field and charged particle environment around our planet changes, these solar winds interact with our planet’s magnetic field to produce the Aurora Borealis aka “The Northern Lights”. Understanding the space environment in the vicinity of our planet is referred to as space weather. For this reason, ISRO is launching Aditya-L1. But bear in mind it is not just the space weather we are interested in, The Sun, or SOL, is the closest star that we have for studying its nature and properties, This mission also aims the understand our Big Ball of Fire, as it is a natural observatory for understanding temperature and magnetic fields of extreme nature which is not possible here on Earth. This observatory will also act as an early warning system for the astronauts in space as if exposed to solar radiation during these solar winds, the effects on their human physiology will be disastrous.

Conclusion:

While the mission is definitely a big challenge for ISRO and its scientists, it is not a complete study of our Sun. But none less will be crucial for us to better understand our star. Solar Parker Probe of NASA and Aditya-L1 together will provide us a ton load of data to go through and analyze what happens on the sun, its nature of the magnetic field, the coronal mass ejection(CMEs), etc. The mission's success will pave the way for future solar missions to come. To know more about the mission here is the link to ISRO’s site: https://www.isro.gov.in/Aditya_L1.html.

References:

1. https://www.nasa.gov/

2. https://www.isro.gov.in/