Aditya L1 nears landmark: Isro to attempt crucial orbit manoeuvre on January 6

TIRUPATI: India's ambitious solar exploration mission, Aditya L1, is gearing up for a historic manoeuvre as it inches closer to its destination, the Lagrange Point (L1), situated 1.5 million km away from Earth.

On January 6, the Indian Space Research Organisation (Isro) would attempt a crucial orbit manoeuvre to place Aditya L1 in a halo orbit around the L1. This strategic positioning will afford the satellite an uninterrupted view of the Sun, allowing it to monitor solar storms, radiations and other emissions before they reach Earth or come under the influence of Earth's magnetic field.

Isro chairman S. Somanath disclosed the upcoming manoeuvre after the successful launch of the Space agency’s maiden X-ray mission, XPoSat. Somanath stated, "Aditya-L1 would reach its L1 point on January 6 at 4 pm. We would do the final manoeuvre to strategically place it in that halo orbit."

Launched in September 2022, the Aditya L1 mission has spent over 125 days in Space and is nearing the L1 point. On Saturday, Isro will attempt a pivotal thruster firing to change the spacecraft’s speed and trajectory to insert it into the intended halo orbit around L1.

This first-of-its-kind manoeuvre for Isro requires precise firing of Aditya L1’s onboard engines to provide the required velocity change. Multiple corrections may be needed if the initial firing misses the target orbit, Somnath said.

“The halo orbit, moving in tandem with the Earth as it orbits the Sun, provides stable gravity and extends the satellite's operational life. From this orbit, the spacecraft will have an unparalleled view of the Sun and solar eruptions.”

“Aditya L1’s instruments can observe explosive events like solar storms before emitted particles propagate towards Earth. This provides vital information on Space weather to safeguard satellites that our technologically advanced society relies on,” the Isro chairman stated.

Four of Aditya L1's seven payloads gaze at the Sun, while three detectors measure in-situ solar wind particles and magnetic fields at the L1 location.

According to Somnath, test results show the remote sensors -- VELC, SUIT, SoLEXS and HELIOS - are functioning beautifully, while the in-situ instruments collected data seamlessly through the journey so far.

The SUIT visible light telescope, seated on top deck with clear line of sight, will be among the first science payloads to power on after entering the halo orbit. From this extremely stable orbit, Aditya L1 can continuously view the Sun without any eclipses or occultation as it moves in synchronisation with Earth’s motion.

 "After the insertion manoeuvre, the orientation would take place, so that the satellite will always look at the Sun as long as its electronics function properly," Somanath said.

This presents an unprecedented opportunity for India to carry out prolonged, simultaneous observations of the solar photosphere, chromosphere and outer corona from the same strategic vantage point.