What is the Aditya-L1 mission?
- The Aditya-L1 will observe the Sun from a close distance, and try to obtain information about its atmosphere and magnetic field. It’s equipped with seven payloads (instruments) on board to study the Sun’s corona, solar emissions, solar winds and flares, and Coronal Mass Ejections (CMEs), and will carry out round-the-clock imaging of the Sun.
Study of the Sun:
- Every planet, including Earth and the exoplanets beyond the Solar System, evolves — and this evolution is governed by its parent star. The solar weather and environment affect the weather of the entire system. Variations in this weather can change the orbits of satellites or shorten their lives, interfere with or damage onboard electronics, and cause power blackouts and other disturbances on Earth. Knowledge of solar events is key to understanding space weather.
- To learn about and track Earth-directed storms, and to predict their impact, continuous solar observations are needed. Every storm that emerges from the Sun and heads towards Earth passes through L1, and a satellite placed in the halo orbit around L1 of the Sun-Earth system has the major advantage of continuously viewing the Sun without any occultation/eclipses.
What is L1?
- L1 refers to Lagrangian/Lagrange Point 1, one of five points in the orbital plane of the Earth-Sun system. Lagrange Points, named after Italian-French mathematician Josephy-Louis Lagrange, are positions in space where the gravitational forces of a two-body system (like the Sun and the Earth) produce enhanced regions of attraction and repulsion.
- These can be used by spacecraft to reduce fuel consumption needed to remain in position. The L1 point is home to the Solar and Heliospheric Observatory Satellite (SOHO), an international collaboration project of NASA and the European Space Agency (ESA).
- The L1 point is about 1.5 million km from Earth, or about one-hundredth of the way to the Sun. Aditya L1 will perform continuous observations looking directly at the Sun.
- NASA’s Parker Solar Probe, launched in 2018, has already gone far closer — but it will be looking away from the Sun.
- The earlier Helios 2 solar probe, a joint venture between NASA and the space agency of erstwhile West Germany, went within 43 million km of the Sun’s surface in 1976.
How much heat will the Aditya-L1 face?
- The Parker Solar Probe during its flyby of the Sun has faced blisteringly hot temperatures of more than one thousand degree Celsius and remained fully operational. The Aditya-L1, however, will not face such heat as it is slated to stay much further away from the Sun in comparison with NASA’s mission. But there are other challenges.
- Many of the instruments and their components for this mission are being manufactured for the first time in India, presenting as much of a challenge as an opportunity for the country’s scientific, engineering, and space communities.