India is set to launch its first space-based solar observatory, Aditya-L1, on September 2, marking a significant milestone in the country’s space exploration journey.
The Indian Space Research Organisation (Isro) has confirmed that all preparations for the launch have been completed and the spacecraft is ready for lift-off from the Sriharikota spaceport at 11:50 am on Saturday.
According to ISRO, the Aditya-L1 mission is the first space-based observatory-class Indian solar mission to study the Sun. It will be placed in a halo orbit around the Lagrangian point (L1) of the Sun-Earth system.
When the country’s maiden solar mission, Aditya L1 onboard the reliable PSLV lifts off from Sriharikota on Saturday for its 125-day voyage towards the Sun, the liquid propulsion systems developed by a key ISRO arm here will play a crucial role in propelling it.
Aditya-L1 spacecraft is designed to provide remote observations of the solar corona and in situ observations of the solar wind at L1 (Sun-Earth Lagrangian point), which is about 1.5 million kilometres from the Earth. Notably, Aditya-L1 is a fully indigenous effort with the participation of national institutions.
It will be the first dedicated Indian space mission for observations of the Sun to be launched by the Bengaluru-headquartered space agency.
“We are just getting ready for the launch. The rocket and satellite are ready. We completed the rehearsal for the launch. So tomorrow, we have to start the countdown for the day after tomorrow’s launch,” Somanath told reporters.
Aditya-L1 will be placed in an orbit around the L1 of the Sun-Earth system, where the gravitational effects of both bodies cancel each other out. That “parking lot” in space allows objects to stay put because of balancing gravitational forces, reducing fuel consumption by the spacecraft.
In 2019, the Centre sanctioned the equivalent of about $46 million for the Aditya-L1 mission. The ISRO has not given an official update on costs.
For the ISRO, success would be another major feat after India became the first country to land a spacecraft close to the lunar south pole in August.
If all goes according to plan, Aditya-L1 will enter into a halo orbit around one of five Lagrange points. From there, Aditya-L1 should enjoy an uninterrupted view of the sun and study in real-time its effect on environmental conditions in the vicinity of Earth and other planets.
The ISRO’s spacecraft can also help scientists dig out the hidden history of the Earth’s climate as solar activities have an impact on the planet’s atmosphere.
India will be one of a small group of countries which are studying the sun.
China has two such spacecraft orbiting Earth, including the Advanced Space-based Solar Observatory launched last year to investigate solar flares and coronal mass ejections.
Hinode, backed by space agencies from Japan, the UK, the US and Europe, is orbiting Earth and measures the magnetic fields of the sun.
The Solar & Heliospheric Observatory mission (SOHO), a joint project of NASA and the European Space Agency, is near the same Lagrange point as the one ISRO is targeting for Aditya-L1. Another joint US-European mission, Solar Orbiter, can travel as close as about 42 million km from the sun.
The US has other solar missions, including the Parker Solar Probe, which in 2021 became the first spacecraft to pass through the sun’s corona, or upper atmosphere.
Lagrangian points are where gravitational forces, acting between two objects, balance each other in such a way that the spacecraft can ‘hover’ for a longer period of time.
The L1 point is considered the most significant of the Lagrangian points, for solar observations, which mathematician Joseph Louis Lagrange discovered.
(With inputs from agencies)