Here comes the Sun: All you need to know about ISRO's Aditya-L1 which successfully performed second Earth-bound manoeuvre

The new orbit attained, after Aditya L1's second Earth-bound manoeuvre on September 5, is 282 km x 40,225 km, according to ISRO.

The Indian Space Research Organisation (ISRO) launched Aditya-L1, India's first solar observatory mission on September 2. And it has successfully undergone a second Earth-bound manoeuvre on September 5, performed from ISTRAC (ISRO Telemetry, Tracking and Command Network), Bengaluru. The new orbit attained is 282 km x 40,225 km, according to news reports. With three more manoeuvres in line, the next, EBN#3, is scheduled for September 10, 2023, around 02.30 am IST, the ISRO has said.

The organisation estimates that the Aditya-L1 mission will arrive at the observing site in four months. A halo orbit will be set up around Lagrangian Point 1 (L1), which is 1.5 million km from Earth and points directly at the Sun.

What is Aditya-L1?

Aditya-L1 is a spacecraft designed explicitly for solar research. It has seven different payloads, all of which were created in-house. There were seven launches, five by ISRO and two by Indian universities working with ISRO.
Aditya means "Sun" in Sanskrit. The Lagrange Point 1 of the Sun-Earth system is referred to here. L1 is the point in space where the Sun's and Earth's gravitational pulls are equal, as the general public understands. As a result, whatever you put there will have a relatively steady orbit around both planets.

The spacecraft's key instruments

The SUIT (Ultraviolet Imaging Telescope) is a continuous ultraviolet imager that catches photographs of the Sun. Observations need the use of the UV spectrum. Its significance stems from the vast amount of ultraviolet and X-ray energy emitted by the Sun's corona.

VELC is a spectrograph that focuses on the corona of the Sun, which is the outermost layer of the Sun's atmosphere. Notably, it extends well beyond the apparent disk of the Sun. Along with SUIT, VELC will monitor the corona and allow ISRO scientists to correlate changes in the corona with events on the Sun's surface.

Mission to study the Sun

The mission's primary goal is to improve India's ability to observe the Sun 24 hours a day. Observing the Sun without obstruction will aid in closely monitoring its activity. Aditya L1 is outfitted with two large and five smaller instruments to achieve its mission.

Aditya L1 is India's first space solar mission. The spacecraft will be in a halo orbit at L1 in the Sun-Earth system 1.5 million km from Earth. The primary benefit of having a satellite in a halo orbit around the L1 point is the uninterrupted, unobstructed view of the Sun that this provides. The use of monitoring the Sun's activity and how it affects space weather in near-real time will be significantly enhanced.

Spacecraft features

The spacecraft is outfitted with electromagnetic, particle, and magnetic field detectors to study the Sun's photosphere, chromosphere, and corona. Important scientific investigations of the propagation effect of solar dynamics in the interplanetary medium are conducted using the unique vantage point L1, with four payloads performing direct solar observations and the remaining three performing in-situ studies of particles and fields at the Lagrange point L1.

What is Aditya-L1 going to do?

During its 16-day Earth orbit, Aditya-L1 performs five manoeuvres to build up the speed it needs to leave the planet. Aditya-L1 then performs a Trans-Lagrangian1 insertion manoeuvre, kicking off its 110-day journey to its final destination near the L1 Lagrange point. Aditya-L1 is manoeuvred to the L1 point, a neutral gravitational region between the Earth and the Sun, and then bound to an orbit around L1. The satellite will spend its entire operational lifetime in an erratic orbit around L1, travelling along a plane that is nearly perpendicular to the line connecting Earth and the Sun.

What else can it detect?

Aditya-L1's position at the L1 Lagrange point guarantees it a direct line of sight to the Sun at all times. The satellite can also detect solar radiation and magnetic storms before Earth's magnetic field and atmosphere alter them by being in this position. Because of its relatively stable gravitational environment, the L1 point is ideal for satellite operations because it reduces the frequency of orbital maintenance.

Aditya-L1 will remain 1.5 million miles from Earth, 1 per cent of the Sun's distance. Aditya-L1 would examine the Sun's heliosphere, or outer atmosphere. Aditya-L1 will not make a solar landing or come closer to the Sun.