Aditya L1 is India’s first solar mission by the Indian Space Research Organization (ISRO). It is scheduled to be launched on September 2, 2023 at 11.50 IST. Aditya L1 is India’s first space solar observatory mission marking a major milestone for India’s space programme. dr. Sankarasubramanian K., ISRO, appointed Chief Scientist of the Aditya-L1 mission.
On August 30, ISRO informed that the launch trials and internal checks of the Aditya L1 spacecraft have been completed. In another tweet, ISRO announced, “Countdown of 23 hours and 40 minutes leading up to the launch at 11:50 am. IST on September 2, 2023, was praised at 12:10 PM today.”
PSLV-C57/Aditya-L1 mission: 23 hours and 40 minutes countdown to launch at 11:50 am. IST on September 2, 2023, was commended today at 12:10 PM.
The launch can be followed LIVE on ISRO website https://t.co/osrHMk7MZL Facebook https://t.co/zugXQAYy1yYouTube…
— ISRO (@isro)
September 1, 2023
The Aditya-L1 spacecraft is scheduled to be launched using the Polar Satellite Launch Vehicle (PSLV). It will be placed in a halo orbit around the Lagrange point (L1) of the Sun-Earth system, which is about 1.5 million km from Earth and about 4 times farther than the Moon. The total travel time of Aditya L1 is expected to be 4 months.
Before we find out which layer of the Sun Aditya L1 will study, let’s understand what the Lagrange point of L1 is.
What is the Lagrange point L1?
For two-body gravitational systems, there are a total of five Lagrange points labeled as L1, L2, L3, L4 and L5. Technically at the Lagrange point, the gravitational force of the two large bodies is equal to the required centripetal force required to keep the small object moving with them. The Lagrange point L1 is located between the Sun-Earth line. (See image below)
A satellite placed in a halo orbit around the L1 point has the great advantage of continuously observing the Sun without any occultation/eclipse. Using the special vantage point L1, four payloads directly observe the Sun, and the remaining three payloads conduct in-situ studies of particles and fields at the L1 Lagrange point.
Also Read: What is Aditya L1? Everything you need to know about India’s first solar mission
Which layer of the Sun will Aditya L1 study?
The Aditya L1 spacecraft carries seven payloads to observe the photosphere (the deepest layer of the Sun that we can directly observe), the chromosphere (the layer above the photosphere) and the corona (the outermost layer) using electromagnetic and particle detectors.
These payloads will measure the temperature, density, composition and dynamics of the corona. They will also study the interaction between the corona and the solar wind, the stream of charged particles that leave the Sun.
Of the seven science payloads, VELC is the main payload on board Aditya-L1.
The Visible Emission Line Coronagraph (VELC) will study the solar corona and the dynamics of coronal mass ejections. It will also send 1,440 images a day to the ground station for analysis as it reaches its planned orbit.
The Solar Ultraviolet Imaging Telescope (SUIT) payload will help image the solar photosphere and chromosphere in the near ultraviolet (UV) and also measure solar irradiance variations in the near UV.
The Aditya L1 payloads are expected to provide the most important information for understanding the problems of coronal heating, coronal mass ejection, pre-flare and flare activity and their characteristics, space weather dynamics, particle propagation studies, fields into the interplanetary medium, etc.
Also Read: Explained: What is a solar flare?