Aditya-L1: Countdown for India’s first mission to Sun begins

New Delhi: Shifting focus to its next space odyssey after successfully placing a lander on the moon’s uncharted South Pole region, the Indian Space Research Organisation (ISRO) is all set for the country’s maiden solar mission — Aditya-L1.

The launch of the sun mission is scheduled for Saturday at 1150 IST from the launch pad at Sriharikota, with the launch rehearsal and vehicle internal checks all being completed.

Aditya-L1 is India’s first solar space observatory and will be launched by the PSLV-C57. It will carry seven different payloads to have a detailed study of the sun, four of which will observe the light from the sun, and the other three will measure in-situ parameters of the plasma and magnetic fields.

The largest and technically most challenging payload on Aditya-L1 is the Visible Emission Line Coronagraph, or VELC. VELC was integrated, tested, and calibrated at the Indian Institute of Astrophysics’ CREST (Centre for Research and Education in Science Technology) campus in Hosakote in collaboration with ISRO.

Aditya-L1 will be placed in a halo orbit around Lagrangian Point 1 (or L1), which is 1.5 million km away from the Earth in the direction of the sun. It is expected to cover the distance in four months’ time.

This strategic location will enable Aditya-L1 to continuously observe the sun without being hindered by eclipses or occultation, allowing scientists to study solar activities and their impact on space weather in real time. Also, the spacecraft’s data will help identify the sequence of processes that lead to solar eruptive events and contribute to a deeper understanding of space weather drivers.

Major objectives of India’s solar mission include the study of the physics of solar corona and its heating mechanism, the solar wind acceleration, coupling and dynamics of the solar atmosphere, solar wind distribution and temperature anisotropy, and origin of Coronal Mass Ejections (CME) and flares and near-earth space weather.

The atmosphere of the sun, the corona, is what we see during a total solar eclipse. A coronagraph like the VELC is an instrument that cuts out the light from the disk of the sun and can thus image the much fainter corona at all times, the Bengaluru-based Indian Institute of Astrophysics said.

On August 23, India took a giant leap as the Chandrayaan-3 lander module successfully landed on the moon’s South Pole, making it the first country to have achieved the historic feat and bringing to an end the disappointment over the crash landing of the Chandrayaan-2, four years ago. Overall, India became the fourth country – after the US, China, and Russia – to have successfully landed on the moon’s surface.

After having landed, the Vikram lander and the Pragyan rover performed different set tasks on the lunar surface, including finding the presence of sulfur and recording relative temperature.

Upon landing, the lander and the rover were to operate for one lunar day. One day on the Moon is equal to 14 days on Earth. The stated objectives of Chandrayaan-3, India’s third lunar mission, were a safe and soft landing on the lunar surface, the rover moving on the moon’s surface, and in-situ scientific experiments.

Chandrayaan-3 is the ISRO’s follow-up attempt after the Chandrayaan-2 mission faced challenges during its soft landing on the lunar surface in 2019 and was eventually deemed to have failed its core mission objectives.