India’s maiden Sun exploration mission, the Aditya L1 spacecraft, has completed its third earth-bound manoeuvre in the early hours of September 10. It has now entered a new orbit of 296 km x 71,767 km.
The satellite is scheduled to carry out five orbital manoeuvres throughout its orbit of the Earth, three of which have already been accomplished. The next manoeuvre is slated to be performed on September 15, at about 02:00 hours (India Standard Time). Earlier, on September 5, it finished the second earth-bound manoeuvre and established an orbit of 282 km by 40,225 km. The first manoeuvre was concluded on September 3.
Indian Space Research Organisation (ISRO) announced the significant development of the ambitious mission on X, previously known as Twitter. Mauritius, Bengaluru, Satish Dhawan Space Centre (Sriharikota Range) and Port Blair stations tracked the satellite during this operation.
Aditya-L1 Mission:
— ISRO (@isro) September 9, 2023
The third Earth-bound maneuvre (EBN#3) is performed successfully from ISTRAC, Bengaluru.
ISRO's ground stations at Mauritius, Bengaluru, SDSC-SHAR and Port Blair tracked the satellite during this operation.
The new orbit attained is 296 km x 71767 km.… pic.twitter.com/r9a8xwQ4My
On September 2, ISRO launched India’s first solar mission, Aditya-L1, from the Satish Dhawan Space Centre in Sriharikota after Chandrayaan-3 made history by landing close to the south pole of the moon. It carries seven payloads that will conduct a detailed study of the sun. Four of these seven payloads are going to study solar light while the other three are set to measure plasma and magnetic field parameters in real time.
Aditya-L1 would be placed in a halo orbit around Lagrange Point 1 (L1) after it reaches its destination, 1.5 million kilometres from Earth. The journey is expected to be completed in four months. Aditya-L1 would orbit the Earth facing the Sun at a distance of about 1.5 million kilometres or 1% of the distance between the two.
Earth-bound manoeuvres
An orbital manoeuvre, also called a burn, is a regular protocol during a spaceflight. During this exercise, the orbit of the satellite or spacecraft is increased by using propulsion systems. This process includes the firing of rockets and also the adjustment of angles.
The best possible illustration of how this function works is to use the example of a swing. When a person is on a swing, pressure is exerted (by changing body weight) during its descent towards the ground to make the swing go higher. Aditya L1 would slingshot around to its intended path towards L1 once it has gained enough speed.
Lagrange Points
There are five Lagrange points between the Earth and the Sun, which bear the name of the Italian-French mathematician Joseph-Louis Lagrange and are the points where a tiny item remains motionless if placed there. The centripetal force necessary for a small object to travel is balanced at these positions by the gravitational pull of the Earth and the Sun.
L1 point
The L1 point is Lagrange Point 1, where the gravitational pull of celestial objects interacts with the spacecraft to allow for parking in a halo orbit or an oval with three axes of motion. Another manoeuvre is scheduled to be carried out to bind Aditya-L1 to the orbit after it reaches the spot.
The spacecraft would employ onboard propulsion to launch to the Lagrange L1 position. It would then be placed into the expansive Halo Orbit that revolves around the Sun’s L1 point. ISRO estimated that it is anticipated to take the Aditya-L1 Mission four months to reach the L1 point after launch.
An ISRO document read, “The satellite spends its whole mission life orbiting around L1 in an irregularly shaped orbit in a plane roughly perpendicular to the line joining the Earth and the Sun.”
Aditya-L1 will be able to continuously monitor the Sun due to the deliberate positioning. “This location also allows the satellite to access solar radiation and magnetic storms before they are influenced by Earth’s magnetic field and atmosphere. The gravitational stability at this point will also minimise the need for frequent orbital maintenance,” ISRO further added.
According to the organisation, the Sun should be studied since it emits radiation with a wide range of wavelengths along with several energetic particles and magnetic fields. The magnetic field and atmosphere of the Earth act as protective shields and neutralise dangerous radiation wavelengths. Solar research is conducted from space to seek out this radiation.
Primary objectives of the mission
The satellite is scheduled to be able to see the sun and help scientists track solar activity and how it affects space weather in real-time without being restricted by eclipses or occultation by undergoing a trans-Lagrangian1 insertion manoeuvre that will take 110 days.
The main goals of the Indian solar mission include the investigation of the physics of the solar corona and its heating mechanism, the solar wind acceleration, coupling, and dynamics of the solar atmosphere, solar wind distribution and temperature anisotropy, and the origin of Coronal Mass Ejections (CME) and flares and near-earth space weather.
