India is poised to make history with its inaugural Solar mission, the Aditya L1 Mission, scheduled for liftoff on September 2, 2023. Spearheaded by the Indian Space Research Organisation (ISRO), this pioneering venture aims to unlock the secrets of our closest star, the Sun, and delve into the enigmatic phenomena unfolding within its blazing confines. 

Aditya-L1 will be launched by PSLV-C57 rocket on September 2 at 11:50 AM.

Mission at a Glance

Leading the charge as the mission director is Dr. Sankarasubramanian K, with S. Somanath at the helm as the ISRO chief. The Aditya L1 spacecraft is poised to assume a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system, positioned approximately 1.5 million kilometres from Earth. Armed with seven cutting-edge scientific payloads, the spacecraft is poised to scrutinize the photosphere, chromosphere, and the outermost layers of the Sun's corona, utilizing an array of electromagnetic, particle, and magnetic field detectors.

Mission Objectives

The Aditya L1 Mission has a robust set of objectives, including:

1. Unravelling Solar Corona Physics: To comprehensively investigate the solar corona's physics and mechanisms responsible for its heating.
2. Exploring Solar Upper Atmospheric Dynamics: To gain insights into the dynamic processes occurring in the Sun's upper atmosphere.
3. Probing Space Weather Drivers: To identify and analyze the factors driving space weather phenomena that affect Earth.
4. In-situ Particle and Plasma Environment: To observe and analyze the particle and plasma environment in the vicinity of the Sun.
5. Understanding Solar Eruptive Events: To discern the sequence of processes underlying solar eruptive events.

Journey to the Lagrange Point 1 (L1)

The Aditya L1 mission is projected to take approximately four months to reach its designated destination, Lagrange Point 1 (L1). Positioned at a distance of around 1.5 million kilometres from Earth and about 148.5 million kilometres from the Sun, this unique vantage point balances the gravitational forces of both celestial bodies. This equilibrium allows the spacecraft to maintain a stable position, enabling uninterrupted solar observations, even during events like solar eclipses.

The Scientific Arsenal

The Aditya L1 spacecraft is armed with seven pivotal scientific payloads, each designed for specific solar observations:

• Visible Emission Line Coronagraph (VELC): The primary payload, VELC, will deliver 1,440 daily images to ground stations for analysis. Its primary function is to capture corona imagery and perform spectroscopy.
• Solar Ultraviolet Imaging Telescope (SUIT): SUIT will be dedicated to capturing images of the photosphere and chromosphere.
• Solar Low Energy X-ray Spectrometer (SoLEXS): This instrument is tailored for observing the Sun in soft X-rays.
• High Energy L1 Orbiting X-ray Spectrometer (HEL1OS): HEL1OS specializes in capturing hard X-ray data from the Sun.

Lagrange Point 1 (L1): An Astronomical Sweet Spot

Lagrange Point 1, or L1, is one of the five Lagrange points in the Sun-Earth system. These points are named after the Italian-born mathematician and astronomer Joseph-Louis Lagrange, who discovered them while solving the "three-body problem" in which three objects orbit each other while also remaining in the same place relative to each other.

L1 is located about 1.5 million kilometres from Earth and about 148.5 million kilometres from the Sun. It is a point where the gravitational forces of the Sun and Earth balance each other out, allowing a spacecraft to remain in a stable position relative to both bodies. This makes it an ideal location for observing the Sun, as it offers an unobstructed view of the Sun even during phenomena like an eclipse.

Key Players in the Mission

The Aditya L1 Mission represents a collaborative endeavour, with the ISRO partnering with esteemed institutions like the Inter-University Centre for Astronomy and Astrophysics in Pune. Numerous scientists have contributed their expertise to the project, with notable figures including:

• Dr. Muthu Priyal: Serving as the Aditya L1 Project Scientist and Operation Manager for VELC, Dr. Priyal is a rising star in solar physics, known for innovative contributions in the field.
• K Sasikumar Raja: A pivotal figure at the Indian Institute of Astrophysics, Raja played a substantial role in the integration, testing, and calibration of the VELC payload.

Dr. Muthu Priyal: A Solar Physics Luminary

Dr. Muthu Priyal, a prominent scientist at the Indian Institute of Astrophysics, Bengaluru, is a force to be reckoned with in the realm of solar physics. With a background in physics and a Ph.D. in astrophysics, Dr. Priyal's pioneering research spans a wide spectrum of solar phenomena. His significant contributions include:

• Innovative Corona Study: Dr. Priyal introduced a novel method employing polarization measurements to study the solar corona.
• Earth-Sun Interaction: His work delves into the intricate dynamics between the Sun and Earth's magnetosphere.
• Instrumentation Advancements: Dr. Priyal is at the forefront of developing cutting-edge instruments for solar corona research.

Dr. Sankarasubramanian K: A Solar Scientist Extraordinaire

Dr. Sankarasubramanian K, a senior solar scientist at the U R Rao Satellite Centre (URSC), Bengaluru, leads the charge as the Principal Scientist of the Aditya-L1 mission. His extensive credentials in physics, optics, and instrumentation make him a driving force in solar research. Some of his notable roles and contributions include:

• X-ray Payload Leadership: Dr. Sankarasubramanian heads the X-ray payload, crucial for studying the solar corona.
• Instrumentation Development: His involvement extends to the development of various scientific instruments aboard the spacecraft.
• Scientific Planning: Dr. Sankarasubramanian plays a pivotal role in charting the scientific observation plans for the mission.
• Knowledge Dissemination: He serves as a conduit for conveying mission results to both the scientific community and the public.

In essence, Dr. Sankarasubramanian K is a dedicated and accomplished scientist, poised to significantly advance our understanding of the Sun's mysteries. His expertise is a cornerstone of the Aditya-L1 mission's success.