Aditya l1

Aditya L1: India's Eye on the Sun

The Sun is the most important star in our solar system. It provides us with light, heat, and energy. It also influences our climate, weather, and space environment. However, the Sun is not a static or simple object. It is constantly changing and evolving, producing various phenomena such as sunspots, flares, coronal mass ejections (CMEs), and solar wind. These phenomena affect the Earth and other planets in various ways, such as causing geomagnetic storms, auroras, satellite disruptions, and power grid failures. Therefore, studying the Sun and its activity is crucial for understanding its impact on our planet and our civilization.

To achieve this goal, India has launched its first solar mission, Aditya L1, on 2 September 2023. Aditya L1 is a coronagraphy spacecraft that will study the solar atmosphere, especially the corona, which is the outermost layer of the Sun. The corona is where most of the solar activity originates and where the solar wind is accelerated. However, the corona is very faint and difficult to observe from the Earth due to the brightness of the solar disk. Therefore, Aditya L1 will use a special instrument called a coronagraph to block out the disk and reveal the corona.

Aditya L1 is not just a coronagraphy spacecraft. It is also a comprehensive solar and space environment observatory that will carry seven scientific payloads to observe various aspects of the Sun and its surroundings. These payloads are:

- Visible Emission Line Coronagraph (VELC): This is the main payload of Aditya L1 that will provide high-resolution images and spectra of the corona in visible and near-infrared wavelengths. It will also measure the magnetic field of the corona using a polarimeter.

- Solar Ultraviolet Imaging Telescope (SUIT): This payload will image the photosphere and chromosphere of the Sun in ultraviolet wavelengths. It will also monitor the solar irradiance in different bands.

- Solar Low Energy X-ray Spectrometer (SoLEXS): This payload will measure the soft X-ray emission from the Sun as a whole. It will also detect solar flares and CMEs in this energy range.

- High Energy L1 Orbiting X-ray Spectrometer (HEL1OS): This payload will measure the hard X-ray emission from the Sun as a whole. It will also detect solar flares and CMEs in this energy range.

- Aditya Solar wind Particle Experiment (ASPEX): This payload will measure the properties of the solar wind particles such as protons and heavier ions with their directions.

- Plasma Analyser Package For Aditya (PAPA): This payload will measure the properties of the solar wind particles such as electrons and heavier ions with their directions.

- Advanced Tri-axial High Resolution Digital Magnetometers: This payload will measure the in-situ magnetic field around Aditya L1.

Aditya L1 is not orbiting around the Earth like most satellites. Instead, it is orbiting around a special point in space called Lagrange point L1. This point is located about 1.5 million km from Earth in the direction of the Sun. At this point, the gravitational forces of the Earth and the Sun balance each other, allowing a spacecraft to maintain a stable orbit with minimal fuel consumption. By orbiting at L1, Aditya L1 will have a continuous view of the Sun without any interruption from Earth's shadow or eclipse.

Aditya L1 is expected to operate for at least five years, providing valuable data and insights into the Sun and its influence on our planet. It will also complement other international solar missions such as NASA's Parker Solar Probe and ESA's Solar Orbiter that are exploring different aspects of the Sun.

Aditya L1 is a landmark achievement for India's space program and scientific community. It is named after Surya and the Adityas, the Hindu deities representing the Sun⁴. It is designed and developed by ISRO and various other Indian research institutes⁵. Nigar Shaji is the project director of Aditya L1. The mission has an allocated cost of ₹378 crores excluding launch costs⁵.

Aditya L1 was launched aboard PSLV C57 at 11:50 IST on 2 September 2023. It successfully achieved its intended orbit nearly an hour later. It is projected to reach its designated orbit at L1 approximately 127 days after its launch. However, there have been some anomalies in the data for orbit determination and alignment of ground station antennas¹. The spacecraft may require a trajectory correction manoeuvre in coming days to achieve L1 orbit³. Moreover, the spacecraft may encounter a powerful coronal mass ejection from the Sun, highlighting the potential hazards faced by space missions².

Despite these challenges, Aditya L1 is a remarkable mission that will enhance our knowledge and understanding of the Sun and its effects on our world. It will also demonstrate India's capabilities and aspirations in space science and exploration. Aditya L1 is India's eye on the Sun.