Aditya L1 begins data collection; ISRO’s Sun probe to escape earth’s gravity tonight

Aditya L1, currently in an earth-bound orbit, has commenced the collection of scientific data, announced the Indian Space Research Organisation (ISRO) on Monday.

India’s first space-based solar observatory is poised to break free from Earth’s gravitational influence in a manoeuvre scheduled for Tuesday at approximately 2am. Thus, it will initiate its four-month journey toward Lagrange Point 1 in the earth-sun system.

The Supra Thermal & Energetic Particle Spectrometer (STEPS) instrument, a component of the Aditya Solar Wind Particle EXperiment (ASPEX) payload, initiated scientific data collection after its activation on September 10, at a distance exceeding 50,000 km from earth, according to ISRO.

The space agency further said that following essential instrument health checks, data collection persisted as the spacecraft moved beyond the 50,000 km mark from earth.

What is the significance of these measurements?

STEPS is equipped with six sensors, each observing different directions and measuring supra-thermal and energetic ions within the range of 20 keV/nucleon to 5 MeV/nucleon, along with electrons surpassing 1 MeV, ISRO said, adding that the measurements are conducted using low and high-energy particle spectrometers.

According to the space agency, the data gathered during earth’s orbits enables scientists to analyse particle behaviour around the earth, particularly in the presence of earth’s magnetic field.

Will Aditya L1 land on the sun? No.

In contrast to Chandrayaan 3, where the Vikram lander, housing the Pragyan rover, made a soft landing near the lunar south pole, the solar probe will instead be stationed at the first Lagrange space point in the earth-sun system.

The distance to the L1 point is 15 lakh kilometres, the spacecraft is expected to cover through various manoeuvres over the course of four months, according to ISRO. Notably, this distance accounts for just 1 per cent of the total 15 crore km separation between earth and the sun.

What’s next for the Aditya L1 mission?

As the spacecraft journeys toward L1, it will depart earth’s gravitational Sphere of Influence (SOI). Following the SOI exit, the cruise phase will commence, and subsequently, the spacecraft will be placed into a large halo orbit around L1. The overall travel time from launch to L1 is estimated to be about four months for Aditya-L1.

These STEPS measurements will persist during the cruise phase and will continue once the spacecraft reaches its intended orbit. Data collected around L1 will provide insights into the origin, acceleration, and anisotropy of solar wind and space weather phenomena, ISRO said.