The satellite will be positioned in a halo orbit around the L1 of the Sun-Earth system, approximately 1.5 million kilometers from Earth
In a significant stride for India’s space programme, following the successful Chandrayaan-3 mission to the moon, the nation is now embarking on a journey toward the sun with Aditya-L1. Launched on September 2, 2023, aboard the PSLV-C57 rocket, Aditya-L1 is a dedicated satellite designed for an in-depth study of the Sun. The satellite boasts seven distinct payloads, five of which are developed by the Indian Space Research Organisation (ISRO), with the remaining two being a collaborative effort between Indian academic institutes and ISRO.
Aditya-L1 is India’s inaugural space-based mission dedicated to the study of the Sun. Aditya, meaning “Sun” in Sanskrit, derives its name from its mission to study the Sun. The “L1” signifies its destination: the Lagrange Point 1 of the Sun-Earth system. For context, L1 is a unique location in space where the gravitational forces of two celestial bodies, in this case, the Sun and Earth, are perfectly balanced. This equilibrium enables an object positioned at L1 to remain relatively stable concerning both celestial bodies.
The journey of India’s first solar observatory commenced with the launch of Aditya-L1. Following liftoff, the satellite is to remain in Earth-bound orbits for 16 days. During this period, it will execute five maneuvers to attain the necessary velocity for its interplanetary journey. On September 3, 2023, just a day after launch, the first Earth-bound maneuver was successfully executed at ISTRAC, Bengaluru, followed by the second on September 5, 2023, and the third on September 10, 2023.
Subsequently, Aditya-L1 will embark on a Trans-Lagrangian1 insertion maneuver, marking the commencement of its 110-day trajectory towards the L1 Lagrange point. Upon reaching the L1 point, another maneuver would bind Aditya-L1 to an orbit around L1, a region of gravitational equilibrium situated between Earth and the Sun. Throughout its mission, the satellite orbits L1 in an irregularly shaped path, roughly perpendicular to the line connecting Earth and the Sun. The satellite will be positioned in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system, approximately 1.5 million kilometers from Earth. This unique vantage point offers continuous, uninterrupted observations of the Sun without eclipses or occultations, providing real-time insights into solar activities and their impact on space weather.
To study how solar wind particles and magnetic fields travel through interplanetary space, measurements must be taken from a location far removed from Earth’s magnetic field
The satellite’s strategic location at the L1 Lagrange point ensures constant surveillance of the Sun and access to solar radiation and magnetic storms before they are influenced by Earth’s magnetic field and atmosphere. Additionally, the stability of the L1 point minimises the need for frequent orbital adjustments, optimising the satellite’s operational efficiency.
In an exciting development, ISRO shared an image taken by Aditya-L1 on September 7, 2023, of Earth and the moon. The selfie image also showcased a portion of the spacecraft including the Visible Emission Line Coronagraph (VELC) and the Solar Ultraviolet Imaging Telescope (SUIT) instruments.
Equipped with seven payloads, Aditya-L1 will observe the photosphere, chromosphere, and the outermost layers of the Sun’s corona using electromagnetic, particle, and magnetic field detectors.
Major science objectives of Aditya-L1 include:
WHY STUDY THE SUN?
Studying the Sun holds immense significance as it is the closest star, offering insights into the workings of stars in our Milky Way and other galaxies. The Sun’s dynamic nature, including eruptive phenomena and the release of vast energy into the solar system, necessitates scientific exploration. Understanding solar phenomena is crucial for mitigating their potential impact on Earth, including disturbances to spacecraft and communication systems, as well as threats to astronauts. The extreme thermal and magnetic conditions of the Sun also serve as a natural laboratory for studying phenomena impossible to replicate in a controlled laboratory environment.
L1 is a unique location in space where the gravitational forces of two celestial bodies, in this case, the Sun and Earth, are perfectly balanced
Observing the Sun from space is essential because the Earth’s atmosphere and magnetic field block many harmful solar radiations, making space-based observations necessary. Additionally, to study how solar wind particles and magnetic fields travel through interplanetary space, measurements must be taken from a location far removed from Earth’s magnetic field, hence Aditya-L1 will be observing the Sun from the L1 point.
The Sun’s constant emissions, including radiation, heat, particles, and magnetic fields, significantly influence Earth and other planets. The solar wind, composed mostly of high-energy protons, fills the entire known solar system and can affect the space environment near planets. Solar events like Coronal Mass Ejections (CMEs) and solar flares can disrupt the Earth’s magnetic field and impact the functioning of space assets. Understanding space weather is crucial as we rely increasingly on technology in space, and insights into near-Earth space weather can provide insights into the behavior of space weather on other planets.
WHAT MAKES ADITYA-L1 UNIQUE?
Aditya-L1’s mission to study the Sun from space represents a significant step in advancing our understanding of solar phenomena and their impact on space weather. This pioneering endeavor will also harness India’s technical prowess and contribute to global efforts to comprehend the Sun’s complex dynamics, ultimately benefiting space exploration and our knowledge of stars beyond our solar system.