Aditya-L1 separates from launch vehicle, on way to Sun

Indian Space Research Organisation (ISRO) chief S Somanath said the spacecraft was injected in the "precise orbit" from Sriharikota off Andhra Pradesh.

"Aditya L1 spacecraft has been injected in an elliptical orbit of 235 by 19,500 km which is intended, very precisely, by the PSLV," he said.

"From now on Aditya L1 will go on a long journey for 125 days," towards the Sun, he said from the Mission Control Center here, flanked by Union Minister Jitendra Singh, Project Director Nigar Shaji and Mission Director Biju.

Shaji said the spacecraft was injected into the orbit flawlessly by the PSLV and that the solar panels were deployed.

Union Minister Singh described the achievement as a "sunshine moment".

Outer atmosphere

The Sun is a giant sphere of gas. Aditya-L1 would study its outer atmosphere. It will neither land on the Sun nor approach it any closer, ISRO said.

It is expected to travel for about 125 days to reach the Halo orbit around the Lagrangian Point L1, which is considered closest to the sun.

Aditya-L1, weighing about 1,480.7 kg, is the first space-based observatory class to study the Sun.

The objectives of the Aditya-L1 mission includes study of the coronal heating, solar wind acceleration, Coronal Mass Ejections, dynamics of solar atmosphere and temperature anisotropy.

The Aditya-L1 will stay in Earth-bound orbits for 16 days, during which it will undergo five manoeuvres to gain the necessary velocity for its journey towards the Sun.

Various manoeuvres

Subsequently, the spacecraft will undergo a Trans-Lagrangian 1 insertion manoeuvre, marking the beginning of its 110-day trajectory to the destination around its destination.

Upon arrival at the L1, another manoeuvre will bind Aditya-L1 to an orbit around the point, which is a balanced gravitational location between the Earth and the Sun.

The spacecraft spends its whole mission life of five years orbiting around L1 in an irregularly shaped orbit in a plane roughly perpendicular to the line joining the Earth and the Sun, ISRO said.

The strategic placement at the L1 Lagrange point ensures the spacecraft 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, ISRO said.

1.5 million km

Additionally, the L1 point's gravitational stability minimises the need for frequent orbital maintenance efforts, optimising the spacecraft's operational efficiency.

Aditya-L1 will stay approximately 1.5 million km away from the Earth, directed towards the Sun, which is about 1 per cent of the Earth-Sun distance.

The PSLV C57 is the 59th flight of the launch vehicle, a trusted workhorse of ISRO and is the 25th mission using PSLV-XL configuration, ISRO said.

The atmosphere of the Earth as well as its magnetic field act as protective shield and block harmful wavelength radiations. In order to detect such radiation, solar studies are carried out from space.

Aditya-L1 mission carries seven scientific payloads to carry out the study.

Various studies

The Visible Emission Line Coronagraph, which studies the solar corona and dynamics of Coronal Mass Ejections, will send 1,440 images per day to the ground station for analysis on reaching the intended orbit.

The Solar Ultraviolet Imaging Telescope payload images the Solar photosphere and Chromosphere in near Ultraviolet and also measures the solar irradiance variations.

The Aditya Solar Wind Particle Experiment (ASPEX) and Plasma Analyser Package for Aditya (PAPA) payloads study the solar wind and energetic ions as well as the energy distribution.

The Solar Low Energy X-ray Spectrometer and the High Energy L1 Orbiting X-ray Spectrometer (HEL1OS) study the X-ray flares from the Sun over a wide X-ray energy range.

The Magnetometer payload is capable of measuring interplanetary magnetic fields at the L1 point.

The Science payloads of Aditya-L1 are indigenously developed with the close collaboration of various centers of ISRO.

(With agency inputs)