The Indian Space Research Organisation (ISRO) is gearing up for its inaugural scientific journey to study the Sun, via a mission named Aditya-L1. This will be ISRO’s second space-based astronomy mission following AstroSat, which was launched in 2015. The spacecraft will be stationed at the L1 Lagrange point in space, a vantage point which allows continuous observation of the Sun without obstruction.
ISRO’s Previous Success: AstroSat
AstroSat, ISRO’s first dedicated astronomy mission, was sent into space in 2015 using the PSLV-C30 from Sriharikota, Andhra Pradesh. This mission aimed at investigating celestial sources across varied spectral bands such as X-ray, optical, and UV. AstroSat marked an important milestone in ISRO’s history of space expeditions.
The Mission Details: Aditya-L1
Originally named Aditya 1 and intended to monitor only the solar corona, it has been renamed to Aditya-L1 to reflect its wider mission scope. The spacecraft will be launched using the Polar Satellite Launch Vehicle (PSLV) XL, carrying 7 payloads.
The objective of Aditya L1 extends to studying the Sun’s corona, photosphere, chromosphere, solar emissions, solar winds and flares, and Coronal Mass Ejections (CMEs). The spacecraft will also carry out around-the-clock imaging of the Sun.
Challenges Faced by Aditya-L1
Unlike previous ISRO missions where payloads remained stationary in space, Aditya-L1 will include moving components, significantly increasing risks of collision. Other challenges include dealing with intense heat and radiation in the solar atmosphere due to its huge distance from Earth (approximately 15 crore kms on average). However, the spacecraft is designed to stay relatively far away, so extreme heat is not expected to heavily impact its onboard instruments.
Importance of Studying the Sun
Every planet’s evolution, including Earth and exoplanets beyond our Solar System, is largely dictated by their parent star – the Sun, in our case. As the Sun’s weather has a considerable effect on the entire system’s weather, it’s crucial to study this celestial entity closely. Understanding solar events is also key to predicting space weather, which can impact Earth.
The Role of Lagrange Point 1
Lagrange Points are named after the Italian-French mathematician Joseph-Louis Lagrange and are positions in space where gravitational forces between two bodies create regions of enhanced attraction and repulsion. The L1 point is approximately 1.5 million km from Earth, offering an uninterrupted view of the Sun. Spacecraft positioned at these points can reduce fuel consumption required to stay in place.
Other Missions to the Sun
NASA’s Parker Solar Probe aims to understand how energy and heat move through the Sun’s corona and to explore the source of solar wind acceleration. This is part of NASA’s ‘Living With a Star’ program that inspects different aspects of the Sun-Earth system. Earlier, the Helios 2 solar probe, a collaboration between NASA and West Germany’s space agency, approached within 43 million km of the Sun’s surface in 1976.
The Aditya-L1 mission represents a significant stride for ISRO and India’s ambitions in space exploration and will contribute uniquely to our understanding of the Sun and its influence on our solar system.
