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Alongside another mission to the Moon, being planned for next year, and the first human space flight scheduled for 2022, the Indian Space Research Organisation (ISRO) is also preparing to send its first scientific expedition to study the Sun. Named Aditya-L1, the mission, expected to be launched early next year, will observe the Sun from a close distance, and try to obtain information about its atmosphere and magnetic field.

ISRO categorises Aditya L1 as a 400 kg-class satellite, that will be launched using the Polar Satellite Launch Vehicle (PSLV) in XL configuration. The space-based observatory will have 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.

The mission will be undertaken in collaboration between various labs of ISRO, along with institutions like the Indian Institute of Astrophysics (IIA), Bengaluru, Inter University Centre for Astronomy and Astrophysics (IUCAA), Pune, and Indian Institute of Science, Education and Research (IISER), Kolkata. Aditya L1 will be ISRO’s second space-based astronomy mission after AstroSat, which was launched in September 2015.

What makes a solar mission challenging is the distance of the Sun from Earth (about 149 million km on average, compared to the only 3.84 lakh km to the Moon) and, more importantly, the super hot temperatures and radiations in the solar atmosphere.

All participating institutions are currently in the final stages of developing their respective payloads. Some payloads have been built, and are in the testing phase with each component being checked and calibrated. Some payloads are at the stage of integration of individual components.

Explained: Eyes on the Sun, how ISRO is preparing for its next giant leap in space

But why is studying the Sun important?

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, which is determined by the processes taking place inside and around the sun, affects 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, ISRO says on its website.

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).

What kind of heat will Aditya L1 face?

The Parker Solar Probe’s January 29 flyby was the closest the spacecraft has gone to the Sun in its planned seven-year journey so far. Computer modelling estimates show that the temperature on the Sun-facing side of the probe’s heat shield, the Thermal Protection System, reached 612 degrees Celsius, even as the spacecraft and instruments behind the shield remained at about 30°C, NASA said. During the spacecraft’s three closest perihelia in 2024-25, the TPS will see temperatures around 1370°C.

Aditya L1 will stay much farther away, and the heat is not expected to be a major concern for the instruments on board. But there are other challenges.

Many of the instruments and their components for this mission are being manufactured for the first time in the country, presenting as much of a challenge as an opportunity for India’s scientific, engineering, and space communities. One such component is the highly polished mirrors which would be mounted on the space-based telescope.



The Supreme Court-appointed interlocutors Sanjay Hegde and Sadhana Ramachandran reached Delhi’s Shaheen Bagh Wednesday to persuade anti-Citizenship Amendment Act protesters to end their blockade of a public road. This was an attempt at court-ordered mediation to resolve an issue of road-blockade.

What is mediation?

Mediation is a procedure to amicably resolve a dispute between two contesting parties, with minimum intervention of the court. It comes under the Alternative Disputes Resolution (ADR) mechanisms as referred to under Section 89 of the Civil Procedure Code.

This allows judges to take up the case only after all avenues to resolve a dispute outside the court have been exhausted. The Supreme Court has also emphasised the effectiveness of mediation to address commercial disputes. Last month, Chief Justice of India S A Bobde pitched for a comprehensive law on making pre-litigation mediation mandatory.

Does it work?

Broadly speaking, no. Despite it being a cost and time-effective ADR mechanism, there is little evidence to suggest mediation has a good success rate.  According to a report by the Supreme Court mediation center, only 29 of the 164 cases taken for mediation in the year 2018 were settled while 94 were not. These include civil dispute cases like property dispute and marital discord.

The latest instance of a Supreme Court-monitored mediation panel that failed to reach consensus was in the Babri Masjid-Ayodhya land dispute case.

Acknowledging that people have a fundamental right to protest, the Supreme Court had appointed two advocates as interlocutors with the mandate to persuade the protesters to move the protest elsewhere. Democracy, the judges said, is about expression of views but “there are lines and boundaries” for it, the court had said.

What next?

Shaheen Bagh protesters have said that while they were open to speak with the authorities, but have no plans of giving up on the protest site.

The Supreme Court will hear the matter again on February 24. It remains to be seen if mediation will work in this case. In its last hearing on the matter on February 17, the court had asked Delhi police to suggest alternatives to the protest site.

The bench had said if nothing works out, “we will leave it to authorities. We are hopeful that some reason will prevail”.





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