Sun Mission: Fourth Orbit raising manoeuvre of Aditya-L1 successful
The fourth earth-bound manoeuvre of the Aditya L1 mission to study the sun was successfully performed by the Indian Space Research Organisation (ISRO) on Friday morning.
Chennai: The fourth earth-bound manoeuvre of the Aditya L1 mission to study the sun was successfully performed by the Indian Space Research Organisation (ISRO) on Friday morning.
The orbit raising was performed at ISRO Telemetry, Tracking and Command Network (ISTRAC), Bengaluru at 0200 hrs early today.
ISRO posted “Aditya L1, India’s first space-based mission to study the Sun, successfully completed its fourth earth-bound manoeuvre in the early hours of Thursday/Friday.
“The fourth Earth-bound manoeuvre (EBN#4) is performed successfully”, it said. ISRO’s ground stations at Mauritius, Bengaluru, SDSC-SHAR and Port Blair tracked the satellite during this operation, while a transportable terminal currently stationed in the Fiji Islands for Aditya-L1 will support post-bu operations,” the space agency wrote on X.
The new orbit attained is 256 km x 121973 km. The next manoeuvre, Trans-Lagragean Point 1 Insertion (TL1I), which marks a send-off from the Earth, is scheduled for around 2 am on September 19. “Aditya L1, India’s first space-based mission to study the Sun, successfully completed its fourth earth-bound manoeuvre in the early hours of Thursday, the Indian Space Research Organisation (Isro) announced.
“The fourth Earth-bound manoeuvre (EBN#4) is performed successfully. Isro’s ground stations at Mauritius, Bengaluru, SDSC-SHAR and Port Blair tracked the satellite during this operation, while a transportable terminal currently stationed in the Fiji Islands for Aditya-L1 will support post-burn operations,” the space agency said.
The Aditya-L1 spacecraft was launched by ISRO’s workhorse launch vehicle PSLV-C57 from the spaceport of Sriharikota, on September 2. After a flight duration of 63 minutes and 20 seconds, AdityaL1 spacecraft was successfully injected into an elliptical orbit of 235 km x 19,500 km around the earth from where the orbit will be raised by firing the onboard propulsion.
Of the total five Orbit raising manoeuvres, the first earthbound manoeuvre was performed on September 3 and the second on September five and the third done on September 10 and the fourth rpt 4th today.
After one more manoeuvre to gain the necessary velocity for its journey, which will be the final manoeuvre on September 19 ending its 16 days stay in Earth-bound orbits, Aditya-L1 will undergo a Trans-Lagrangian1 insertion manoeuvre, marking the beginning of its 110-day trajectory to the destination around the L1 Lagrange point.
As the spacecraft travels towards L1, it will exit the Earths’ gravitational Sphere of Influence (SOI). After exit from SOI, the cruise phase will start and subsequently the spacecraft will be injected into a large halo orbit around L1.
The total travel time from launch to L1 takes about four months for Aditya-L1. Upon arrival at the L1 point, another manoeuvre binds Aditya-L1 to an orbit around L1, a balanced gravitational location between the Earth and the Sun.
AdityaL1 will be the first Indian space-based observatory to study the sun from a halo orbit around first sun earth Lagrangian point (L1), which is located roughly 1.5 million km from earth.
A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the Sun without any occultation/eclipse. This will provide a greater advantage of observing the solar activities continuously.
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.
The strategic placement at the L1 Lagrange point ensures that Aditya-L1 can maintain a constant, uninterrupted view of the Sun. This location also allows the satellite to access solar radiation and magnetic storms before they are influenced by Earth’s magnetic field and atmosphere.
Additionally, the L1 point’s gravitational stability minimizes the need for frequent orbital maintenance efforts, optimizing the satellite’s operational efficiency. Aditya-L1 will stay approximately 1.5 million km away from Earth, directed towards the Sun, which is about 1% of the Earth-Sun distance.
The Sun is a giant sphere of gas and Aditya-L1 would study the outer atmosphere of the Sun. Aditya-L1 will neither land on the Sun norapproach the Sun any closer.
Aditya-L1 is a satellite dedicated to the comprehensive study of the Sun. It has 7 distinct payloads developed, all developed indigenously–five by ISRO and two by Indian academic institutes in collaboration with ISRO.
Aditya in Sanskrit means the Sun. L1 here refers to Lagrange Point 1 of the Sun-Earth system. For common understanding, L1 is a location in space where the gravitational forces of two celestial bodies, such as the Sun and Earth, are in equilibrium.
This allows an object placed there to remain relatively stable with respect to both celestial bodies.
The spacecraft has seven payloads to observe the photosphere, chromosphere and the outermost layers of the Sun (the corona) using electromagnetic and particle detectors.
Using the special vantage point of L1, four payloads will directly view the Sun and the remaining three payloads will carry out in-situ studies of particles and fields at the Lagrange point L1. ISRO said the suit of Aditya L1 payloads are expected to provide most crucial information to understand the problems of coronal heating, Coronal Mass Ejection, pre-flare and flare activities, and theircharacteristics, dynamics of space weather, study of the propagation of particles, fields in the interplanetary medium, etc.
For a two-body gravitational system, the Lagrange Points are the positions in space where a small object tends to stay, if put there. These points in space for a two-body system such as Sun and
Earth can be used by the spacecraft to remain at these positions with reduced fuel consumption.
Technically at Lagrange point, the gravitational pull of the two large bodies equals the necessary centripetal force required for a small object to move with them. For two-body gravitational systems, there are total five Lagrange points, denoted as L1, L2, L3, L4, and L5. The Lagrange point L1 lies between Sun Earth line. The distance of L1 from Earth is approximately 1% of the Earth-Sun distance.
