Aditya L1 Mission: Spacecraft is nearing its final phase, says ISRO chief

Aditya L1 spacecraft is nearing its final phase, and manoeuvres to enter the L1 point are expected to be completed by January 7, 2024, according to ISRO Chairman S Somanath. “Aditya is on the way. I think it has reached almost its final phase,” the ISRO chief told PTI on the sidelines of an event organised at VSSC to commemorate the 60th year of the First Sounding Rocket Launch. Aditya L1, India’s first space-based mission to study the Sun, was successfully launched on September 2 from the Satish Dhawan Space Centre (SDSC) in Sriharikota. The spacecraft, after travelling about 1.5 million km from Earth over 125 days, is expected to be placed in a Halo orbit around the Lagrangian point L1, considered closest to the Sun. He said that the last preparations for the spacecraft’s entry into the L1 point are currently underway incrementally.“Possibly by January 7th, the final manoeuvres will be done for entering into the L1 point,” Somanath added. Among other tasks, it will capture and transmit pictures of the Sun for scientific experiments. What is the Aditya-L1 mission? The Aditya-L1 is an ‘observatory’ or spacecraft that will monitor the Sun 24×7. This will be the first time that India will put a spacecraft on a Lagrange point – a position in space where, as per NASA, “the gravitational forces of a two-body system like the Sun and Earth produce enhanced regions of attraction and repulsion”. There are five Lagrange points in the Sun-Earth system; India’s solar mission will be placed in a halo orbit around Lagrange point 1, or L1, which is about 1.5 million km from the Earth, according to ISRO. L1, Aditya’s parking spot, has been housing Solar and Heliospheric Observatory, a project by America’s NASA and the European Space Agency (ESA) since 1996, reported Space.com. The Aditya-L1 mission will carry seven payloads, out of which four will directly observe the Sun. These seven payloads or scientific instruments include Visible Emission Line Coronagraph(VELC), Solar Ultraviolet Imaging Telescope (SUIT), Solar Low Energy X-ray Spectrometer (SoLEXS), High Energy L1 Orbiting X-ray Spectrometer (HEL1OS), Aditya Solar wind Particle Experiment (ASPEX), Plasma Analyser Package For Aditya (PAPA) and Advanced Tri-axial High Resolution Digital Magnetometers. These instruments will study the photosphere or the Sun’s visible surface; the layer above the photosphere known as the chromosphere; and the corona – the outermost part of the Sun’s atmosphere. Objectives of Aditya-L1 mission As per  ISRO , the spacecraft will examine the dynamics of the chromosphere and corona; in-situ particle and plasma environment; the heating mechanism of the corona; magnetic field topology and magnetic field measurements in corona; temperature, velocity and density of coronal and coronal loops plasma; and development, dynamics and origin of coronal mass ejections (CMEs). It will also study chromospheric and coronal heating, space weather, the physics of the partially ionized plasma, what leads to solar eruptive events, and how CMEs and solar flares start. Why is studying the Sun important? Before that, here are some facts about the centre of our solar system. The Sun, which sustains most life on Earth, is a 4.5 billion-year-old star. Located 150 million kilometres away from the  Earth , the Sun’s gravity holds the solar system together. Unlike Earth, the Sun’s surface is not solid but made of “super-hot, electrically charged gas called plasma”, noted NASA. According to the US Space Agency, “The Sun’s activity, from its powerful eruptions to the steady stream of charged particles it sends out, influences the nature of space throughout the solar system.” The solar activity constitutes solar flares, CMEs or huge plasma clouds, high-speed solar wind, and solar energetic particles. With inputs from agencies.