While Chandrayaan-3 gets closer to the moon, and is scheduled to land on 23 August, the Indian Space Research Organisation (Isro) is also getting ready to reach the sun. Aditya-L1, the first space-based Indian observatory to study the Sun, will be launched soon, the Indian space agency announced on 14 August.
Isro took to X to give an update about the mission to reach the sun earlier this week. “The satellite realised at the U R Rao Satellite Centre (URSC), Bengaluru has arrived at SDSC-SHAR, Sriharikota,” the post said. It will likely launch in the first week of September, an Isro official told the Press Trust of India.
The Sun is the nearest star and the largest object in the solar system. It is estimated to be about 4.5 billion years old. Earth's distance from the hot glowing ball of hydrogen and helium gases is about 150 million kilometres, according to Isro. The visible surface of the sun, known as the photosphere, is relatively cool and has a temperature of about 5,500°C. The outermost layer of the sun is called the corona.
It’s a one-of-kind mission to study the Sun’s outer atmospheric dynamics as well as the factors that drive weather in space. The spacecraft is expected to be placed in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth systems, which is about 1.5 million kilometres from the Earth, according to Isro’s official website.
Placing a satellite in the halo orbit around the L1 point offers the huge advantage of continuously viewing the Sun without any eclipses. “This will provide a greater advantage of observing the solar activities and its effect on space weather in real-time,” the Isro website explains.
The spacecraft will carry seven payloads to observe the Sun’s outermost layers – including the photosphere, chromosphere, and the outermost layers – using electromagnetic and particle and magnetic field detectors.
In lay terms, payloads are additional cargo carried by the spacecraft along with what is necessary for the operation. Using the L1 point, four payloads will directly view the Sun and the remaining will conduct studies of particles and fields at the L1 point.
Studying the sun can provide much more information about stars in the Milky Way as well as about stars in various other galaxies, according to Isro. Notably, the many thermal and magnetic phenomena of the sun are extreme. Thus, it can be “a good natural laboratory to understand those phenomena which cannot be directly studied in the lab,” it added.
This mission aims to understand the coronal heating and solar wind (constant flow of particles from the sun) acceleration as well as initiation of coronal mass ejection, flares, and near-earth weather, according to Isro. It can also further knowledge about solar wind distribution.
