Aditya-L1 will be launched in PSLV’s 59th flight. The PSLV, in its XL configuration, will place the spacecraft in a highly eccentric Earth-bound orbit, from where, the spacecraft will perform multiple orbital manoeuvres by using its liquid apogee motors (LAM) — powerful engines that will play a critical role in taking it to its destination — to reach the Lagrange Point-1 (L1) about 1.5-million-km away.That is 1/100th of the distance between Earth and Sun.
Aditya L1 mission: Live updates
Aditya-L1 is a satellite dedicated to the comprehensive study of the Sun. It has seven distinct payloads — five by Isro and two by academic institutions in collaboration with Isro — developed indigenously.
“Aditya in Sanskrit means the Sun. L1 (about 1.5-million-km from Earth) refers to Lagrange Point 1 of the Sun-Earth system. For common understanding, L1 is a location in space where the gravitational forces of two celestial bodies, such as the Sun and Earth, are in equilibrium. This allows an object placed there to remain relatively stable with respect to both celestial bodies,” Isro said.
Following its scheduled launch on September 2, Aditya-L1 will stay in Earth-bound orbits for 16 days, during which it will undergo five manoeuvres to gain the necessary velocity for its journey.
“Subsequently, Aditya-L1 undergoes a Trans-Lagrangian1 Insertion (TLI) manoeuvre, marking the beginning of its 110-day trajectory to the destination around the L1 Lagrange point. Upon arrival at the L1 point, another manoeuvre binds Aditya-L1 to an orbit around L1, a balanced gravitational location between the Earth and the Sun,” Isro said.
It added that the satellite spends its whole mission life orbiting around L1 in an irregularly shaped orbit in a plane roughly perpendicular to the line joining the Earth and the Sun.
The strategic placement at the L1 Lagrange point ensures that Aditya-L1 can maintain a constant, uninterrupted view of the Sun. This location also allows the satellite to access solar radiation and magnetic storms before they are influenced by Earth’s magnetic field and atmosphere.
Additionally, the L1 point’s gravitational stability minimises the need for frequent orbital maintenance efforts, optimising the satellite’s operational efficiency.
India’s solar mission comes close on the heels of its successful lunar endeavour — Chandrayaan-3. With Aditya-L1, Isro will venture into the study of solar activities and its effect on space weather. The scientific objectives of Aditya-L1 include the study of coronal heating, solar wind acceleration, coronal mass ejections (CMEs), dynamics of solar atmosphere and temperature anisotropy.
To achieve this, the spacecraft is packed with seven scientific instruments: The two main payloads are Visible Emission Line Coronagraph (VELC) for Corona imaging & spectroscopy studies and Solar Ultraviolet Imaging Telescope (SUIT) for Photosphere and Chromosphere imaging (narrow & broadband).
The others are: Solar Low Energy X-ray Spectrometer (SoLEXS) for soft X-ray spectrometer: Sun-as-a-star observation; High Energy L1 Orbiting X-ray Spectrometer(HEL1OS) for hard X-ray spectrometer: Sun-as-a-star observation; Aditya Solar wind Particle Experiment(ASPEX) for solar wind; Plasma Analyser Package For Aditya (PAPA) for Solar wind; can do particle analysis and the Advanced Tri-axial High Resolution Digital Magnetometers for in-situ magnetic field studies.