The Indian Space Research Organisation (ISRO) has placed the Aditya-L1 spacecraft in a halo orbit around the Lagrangian point (L1).
Key points
- India’s first solar mission Aditya-L1 reached the L1 point on January 6, 127 days after it was launched on September 2, 2023.
- After a 1.5-million km journey the spacecraft was placed in a halo orbit around L1 following a firing manoeuvre which was carried out by ISRO scientists at the ISRO Telemetry Tracking and Command Network (ISTRAC) in Bengaluru.
- The orbit of Aditya-L1 spacecraft is a periodic halo orbit which is located roughly 1.5 million km from earth on the continuously moving Sun–Earth line with an orbital period of about 177.86 earth days.
- This halo orbit is a periodic, three-dimensional orbit at L1 involving Sun, Earth and a spacecraft.
- This specific halo orbit is selected to ensure a mission lifetime of 5 years.
- The distance of L1 from the earth is approximately 1% of the earth-sun distance.
- The Aditya-L1 satellite will be continuously viewing the sun without any occultation or eclipse and provides a greater advantage of observing the solar activities without obstruction.
- Aditya-L1 carries seven payloads to observe the photosphere, chromosphere, and the outermost layer of the sun (corona) using electromagnetic and particle detectors.
- Using the special vantage point of L1, four payloads will directly view the sun and the remaining three payloads will carry out in-situ studies of particles and fields at the L1.
About Lagrange Points (L)
- The Lagrange Points are the positions in space where a small object tends to stay, if put there.
- These points in space for a two-body system such as sun and earth can be used by the spacecraft to remain at these positions with reduced fuel consumption.
- For two-body gravitational systems, there are total five Lagrange points, denoted as L1, L2, L3, L4, and L5.
- The L1 lies between the sun-earth line which is about 1.5 million km from the earth.
- The distance of L1 from the earth is approximately 1% of the earth-sun distance. A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the sun without any occultation/eclipse.
- This will provide a greater advantage of observing the solar activities continuously.
- There are currently four operational spacecraft at L1. These are: WIND, Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE) and Deep Space Climate Observatory (DSCOVER).
