The Indian Space Research Organisation’s (ISRO) ambitious solar exploration mission Aditya-L1 has travelled beyond a distance of 9.2 lakh kilometres from Earth, successfully escaping the sphere of Earth's influence. It is now navigating its path towards the Sun-Earth Lagrange Point 1 (L1), the national space agency informed in a tweet on X platform.
It's remarkable that this is the second time in a row that ISRO has sent a spacecraft outside the Earth's sphere of influence, the first being the Mars Orbiter Mission.
Aditya-L1 mission was launched by ISRO’s PSLV XL rocket on September 2, 2023 at 11.50 am from Sriharikota.
Initially, the spacecraft will be placed in a low earth orbit. Subsequently, the orbit will be made more elliptical and later the spacecraft will be launched towards the Lagrange point (L1) by using onboard propulsion.
As the spacecraft travels towards L1, it will exit the Earth’s gravitational sphere of influence (SOI). After exit from SOI, the cruise phase will start and subsequently the spacecraft will be injected into a large halo orbit around L1. The total travel time from launch to L1 would take about four months for Aditya-L1.
About the Sun Mission
Aditya L1 shall be the first space based Indian mission to study the Sun. The spacecraft shall be placed in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system, which is about 1.5 million km from the Earth. A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the Sun without any occultation/eclipses. This will provide a greater advantage of observing the solar activities and its effect on space weather in real time. The spacecraft carries seven payloads to observe the photosphere, chromosphere and the outermost layers of the Sun (the corona) using electromagnetic and particle and magnetic field detectors. Using the special vantage point L1, four payloads directly view the Sun and the remaining three payloads carry out in-situ studies of particles and fields at the Lagrange point L1, thus providing important scientific studies of the propagatory effect of solar dynamics in the interplanetary medium.
The suits of Aditya L1 payloads are expected to provide most crucial informations to understand the problem of coronal heating, coronal mass ejection, pre-flare and flare activities and their characteristics, dynamics of space weather, propagation of particle and fields etc.
Science Objectives:
The major science objectives of Aditya-L1 mission are:
· Study of Solar upper atmospheric (chromosphere and corona) dynamics.
· Study of chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections, and flares
· Observe the in-situ particle and plasma environment providing data for the study of particle dynamics from the Sun.
· Physics of solar corona and its heating mechanism.
· Diagnostics of the coronal and coronal loops plasma: Temperature, velocity and density.
· Development, dynamics and origin of CMEs.
· Identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.
· Magnetic field topology and magnetic field measurements in the solar corona.
· Drivers for space weather (origin, composition and dynamics of solar wind.
