Aditya-L1: 127-day journey paves way for crucial data on space weather

The Aditya-L1 spacecraft on Saturday completed a 127-day journey to reach its final parking spot, readying itself for five years of crucial observations about various aspects of the Sun.

After the successful insertion of Aditya-L1 into a Halo Orbit around Lagrange Point 1, a region about 1.5 million km from the Earth, Isro chief S Somanath said that the satellite will have a mission life of at least five years and findings collated in this period will be significant not just for Indian scientific community but for the world.

"Understanding the Sun is not important for India alone, everyone around the world is looking forward to the findings," Somanath said in his address to media after the space agency's scientists performed the final set of manoeuvres to place the craft in a halo orbit around L1.

From L1, the spacecraft will be able to see how particles and radiation from heightened solar activity has an effect, while also studying the outer surface of the star in close detail — something that is normally not possible from the Earth, or even its orbit.

Giving details about the 1.5 million km journey of the craft, Annapurni Subramaniam, director of Indian Institute of Astrophysics, said it was completed in three phases — the earth-bound orbit, the cruise phase and finally the insertion of the craft into the halo orbit. Now the orbit phase of the mission will start where the experiments will be turned on.

"This is a big milestone for us. Now that the craft has been inserted into a halo orbit around L1, we will start the process of operating all the science instruments on-board. The next phase will be a performance evaluation phase and we will start receiving data," Subramaniam said. IIA designed the primary payload, the Visible Emission Line Coronagraph (VELC).

Experts associated with the mission said that in the coming days, shutters of all instruments on board will be opened, operationalising them. After a few rounds of tests, the first set of data will also start coming in.

"By mid-January, we should start receiving the first set of data from L1," said Jagdev Singh, the first principal investigator of India's solar mission.

The country's first solar observatory is carrying seven payloads to study the Sun's corona, chromosphere, photosphere and solar wind.

The seven payloads include — VELC, which is the primary payloads; Solar Ultraviolet Imaging Telescope (SUIT); Solar Low Energy X-ray Spectrometer (SoLEXS); High Energy L1 Orbiting X-ray Spectrometer (HEL1OS), which are remote sensing payloads; Aditya Solar wind Particle Experiment (ASPEX), Plasma Analyser Package for Aditya (PAPA), Advanced Tri-axial High Resolution Digital Magnetometers, which are in-situ payloads.

Using the special vantage point L1, four payloads (VELC, SUIT, SoLEXS, HEL1OS) will directly view the sun, and the remaining three payloads (ASPEX, PAPA and Advanced Tri-axial High Resolution Digital Magnetometers) will carry out in-situ studies of particles and fields at L1, providing scientific studies of the propagatory effect of solar dynamics in the interplanetary medium, the space agency said.

Somanath said that Aditya-L1 mission will unravel many aspects of the space weather, which will prove to be a crucial for the scientific community world over.

The National Aeronautics and Space Administration (NASA) in its documents have highlighted that activity on the Sun's surface creates a type of weather called space weather. While the Sun is around 150 million kms from the Earth, space weather can affect Earth and the rest of the solar system, in worst cases damaging satellites and causing electrical blackouts on Earth.