Surya Namaskar: Aditya L1 mission

Hi everyone!

I hope all of you are hale and hearty. Today I'll be sharing some information on Aditya-L1 mission.

Journey to the Heart of Our Solar System

Aditya L1 is India's first solar mission. Aditya in Sanskrit means the Sun. This mission is dedicated to study the Sun and to unlock many of the mysteries that have long intrigued scientists and space enthusiasts alike. It is a satellite-based mission which was launched by the Indian Space Research Organisation (ISRO) at 11.50 am on 2nd September 2023 from Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh. The spacecraft, weighing 1,472 kg, was carried into space by the Polar Satellite Launch Vehicle (PSLV). The solar mission follows India beating Russia. to become the first country to land on the south pole of the moon. 

Why Sun?

 

The Sun is a central figure of our Solar System providing light and energy to sustain life on Earth. It is not only a vital source of heat and light but also plays a pivotal role in space weather. Studying the Sun enhances our understanding of the dynamics of our solar neighborhood. Exploring the Sun's complex behavior, including its magnetic fields, heating mechanisms, and plasma dynamics, contributes to advances in fundamental physics and astrophysics. Solar radiation and solar wind affect the functioning of satellites and spacecraft. Understanding these solar interactions allows for better spacecraft design and operation. Studying the Sun from Earth can’t provide a complete picture and it becomes crucial to observations from outside the planet’s atmosphere i.e., from space.

Few Terminologies 

• Space Weather: Activity on the Sun’s surface creates a type of weather called space weather that can affect technologies, systems, and even human health both in space and on Earth. 
• Corona: The corona is the outermost layer of the Sun's atmosphere, and it is primarily composed of plasma consisting of hot, ionized gas.
• Chromosphere: The chromosphere is a thin layer of plasma that lies between the Sun's visible surface (the photosphere) and the corona (the Sun's upper atmosphere)
• Solar Winds: The solar wind is a continual stream of protons and electrons from the sun's corona. When the solar wind reaches Earth it sends a flurry of charged particles into the magnetosphere and along Earth's magnetic field lines, towards the poles. The interaction of these particles with Earth's atmosphere can produce glowing aurora displays or northern lights. 
  
  
  
  
  

Objectives of Aditya L1 mission

• It will study the Solar upper atmospheric (chromosphere and corona) dynamics.
• Study about Coronal Mass ejections (CMEs). They are large expulsions of plasma and magnetic field from the Sun's surface- Corona. 
• Identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.
• Study of chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections, and flares
• Observe the in-situ particle and plasma environment providing data for the study of particle dynamics from the Sun.
• Physics of solar corona and its heating mechanism.
• Diagnostics of the coronal and coronal loops plasma: Temperature, velocity and density
• Study corona’s magnetic field and the driver of the space weather.
  
  

What is the mission carrying?

It will carry seven payloads to orbit to observe the photosphere, chromosphere and outermost layers of the Sun’s atmosphere.

• Visible Emission Line Coronagraph (VELC): Corona/Imaging & Spectroscopy
• Solar Ultraviolet Imaging Telescope (SUIT): Photosphere and Chromosphere Imaging- Narrow & Broadband
• Solar Low Energy X-ray Spectrometer (SoLEXS): Soft X-ray spectrometer: Sun-as-a-star observation
• High Energy L1 Orbiting X-ray Spectrometer (HEL1OS): Hard X-ray spectrometer: Sun-as-a-star observation.
• Aditya Solar wind Particle Experiment (ASPEX): Solar wind/Particle Analyzer Protons & Heavier Ions with directions
• Plasma Analyzer Package for Aditya (PAPA): Solar wind/Particle Analyzer Electrons & Heavier Ions with directions
• Advanced Tri-axial High Resolution Digital Magnetometers: In-situ magnetic field (Bx, By and Bz).
  
  
  
  
  
  

How will Aditya L1 survive?

Aditya L1 will be at a mere one percent of the Sun-Earth distance. The Sun's heat is still very intense at this distance. The Aditya L1 mission uses a Multi-Layer Insulation (MLI) system to shield itself from the Sun's intense heat, ensuring it stays cool enough to function properly. To manage its temperature effectively, the spacecraft relies on a liquid helium-based cooling system. Liquid helium, known for its extreme coldness and remarkable heat-absorbing properties, is employed to chill the spacecraft's instruments to about -270°C. In addition to the MLI and cooling system, Aditya L1 is equipped with other protective measures, including radiation shielding and a sunshade. These safeguards are essential for the spacecraft to withstand the challenging conditions of space and continue operating as planned throughout its mission.

Some Facts on Aditya-L1 mission

• If Aditya L1 is successful, India will join a select group of countries that are already studying the Sun.
• Nigar Shaji, a woman ISRO scientist helmed Aditya-L1 mission

• While AstroSat, India’s first astronomy mission launched in 2015, aimed at studying celestial sources in X-ray, optical, and UV spectral bands simultaneously, remains operational till now, Aditya-L1 can potentially pave the way for future Indian astronomy missions.
• Aditya L1 shall be the first space-based Indian mission to study the Sun. Only two other space agencies have had their spacecraft reach the Lagrange point: USA's National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA).
• Aditya L1 will reportedly stay in Earth-bound orbits for 16 days, till 18 September.
• Aditya L1 is a purely scientific endeavour, unlike the Moon missions that are exploring opportunities for resource utilisation and extraction, and setting up facilities
• Initially, the spacecraft will be placed in a low Earth orbit (LEO). From there, the orbit of the spacecraft will be made more elliptical to place it in the Lagrange point L1 of the Earth-Sun system. The total travel time from its launch to placement in L1 is expected to be about four months.
  

  
  
  
• Aditya L1 Mission will not "land" on the Sun. It will be placed in the orbit of the Sun-Earth system.

What is L1 and Why L1?

L1 stands for Lagrange point Named after 18th century Italian-born astronomer Joseph-Louis Lagrange, the Lagrange point is where gravity from the Sun and Earth balance the motion of a satellite. 

L1 is one of five such points, situated between Earth and Sun. L1 is not an object, it is a location in space, which moves with Earth around the Sun
L1 has an unhindered view of the Sun, L2 is located behind the Earth while L3 is behind the Sun, L4 and L5 are stable locations but are much farther from Earth compared to L1, which is directly between the Sun and Earth.

Past Solar Missions done by Various Countries

• Japan: Japan’s space agency JAXA’s first solar observation satellite was named Hinotori (ASTRO-A). Japan was the first to launch a mission to Sun in 1981 to study solar flares. Japan has been actively involved in several solar exploratory missions, Yohkoh (SOLAR-A), launched in 1991; SOHO (a collaborative mission with NASA and ESA) in 1995; and Transient Region and Coronal Explorer (TRACE), developed in partnership with NASA, in 1998 and Hinode (SOLAR-B) in 2006.

• United States: NASA launched the SOHO mission in collaboration with ESA and JAXA in 1995, Advanced Composition Explorer launched in August 1997; Solar Terrestrial Relations Observatory in 2006; Solar Dynamics Observatory in 2010; and Interface Region Imaging Spectrograph launched in 2013. NASA's Parker Solar Probe "touched" the Sun for the first time in history in 2021. The probe navigated Sun's upper atmosphere, known as the corona, and sampled particles and magnetic fields within.
  
  
• Europe: The European Space Agency (ESA) has a history of collaboration on solar missions with NASA and JAXA. One of ESA's notable missions was the Ulysses mission in 1990, focusing on studying the Sun's polar environments. In 2001, ESA initiated the Project for On-Board Autonomy-2 (Proba-2) mission, featuring two solar observation experiments. Looking ahead, ESA has plans for upcoming solar exploration missions, including Proba-3 in 2024 and Smile in 2025. These missions are set to contribute further to our understanding of the Sun and its phenomena.
  
  
• China: The Advanced Space-based Solar Observatory (ASO-S) was successfully launched by the National Space Science Center, Chinese Academy of Sciences (CAS), in 2022.
  
  
  

What's Next

After the successful launch of India's mission to the Sun, ISRO will conduct first trial for Gaganyaan in October.

Thank you for taking the time to read this blog. Your attention is truly appreciated. Until next time, stay curious and keep exploring!

Image Courtesy: ISRO, Wion, The Statesman, Drishti, ESA, National Geographic, NASA, Scientific American, Business Today, Pinterest, The Sun Today, ED times