ISRO's solar mission Aditya-L1 is all set to finally take off by the end of 2021. The satellite will travel a distance of 1.5 million kilometres from the Earth to study the Sun’s atmosphere.
Looks like India’s first solar mission will finally see the light of the day by the end of 2021 after it was delayed due to the Covid-19 pandemic, according to people at the ISRO. The launch of the Aditya L-1 mission was previously slated for the first half of 2020. The satellite will be launched by PSLV-XL launch vehicle from Sriharikota. The mission is almost ready for launch, people aware of the developments told Hindustan Times.
The satellite will be placed at the L1 or Lagrangian point between the Earth and the Sun, which is where the gravitational pull of both the celestial bodies balances each other out which makes it easy for the satellite to stay in orbit.
The mystery that ISRO aims to solve!
There has been a long-unsolved question in solar physics that the mission aims to solve—coronal heating. The Sun’s corona (outermost layer of the solar atmosphere) is abnormally hot with temperatures in the range of millions of degrees. Whereas, the Sun’s surface is about 5,600 Degree Celsius. It is difficult to explain this abnormally hot corona with the help of the laws of thermodynamics. Scientists believe that this is not the result of thermal heating, but magnetic heating.
Why do we need to study the Sun?
The Sun is the closest star to us, and studying it can provide us with an insight into the innermost working of the stars. The research on the Sun and what goes on in it has helped us make many advances over the years, like a better understanding of nuclear physics, the discovery of helium, and even the discovery of neutrino oscillations. It has also helped scientists to discover the outlines of how stars work.
Onboard Aditya L1
The mission will carry six scientific payloads that will study the photosphere (the visible surface of the sun,) the Chromosphere (the irregular layer over the photosphere) and Corona (the layer of plasma) which extends for thousands of kilometres. The instruments on the mission will help us in studying the impact of the Sun’s magnetic activity on space weather.
- The Visible Emission Line Coronagraph (VELC), is being built at the Indian Institute of Astrophysics, Bengaluru. It will help us figure out the coronal temperature by measuring the density and strength of the magnetic field in the corona.
- The Solar Ultraviolet Imaging Telescope (SUIT) is being designed by the Inter-University Centre for Astronomy & Astrophysics (IUCAA), Pune. It will measure the UV radiation emitted from the Sun, which is a primary determinant of life of Earth.
- Two X-ray spectrometers will help us in studying the X-rays radiated during solar flares. The Solar Low Energy X-ray Spectrometer (SoLEXS) will analyse low-energy X-rays. The High Energy L1 Orbiting X-ray Spectrometer (HEL1OS) will estimate the energy used to accelerate particles during eruptive events like solar flares.
- The Aditya Solar wind Particle Experiment (ASPEX) has been designed by the Physical Research Laboratory (PRL) at Ahmedabad. It looks at the variations in the properties of the solar wind, and its distribution and spectral characteristics.
- The Plasma Analyser Package for Aditya (PAPA) being designed by ISRO’s Vikram Sarabhai Space Centre will help us to understand the composition of the solar wind.
- A magnetometer, called MAG has been built by ISRO’s Laboratory for Electro-Optics Systems (LEOS). It measures the enhancement in the magnetic field when a solar storm is passing.
Other Solar Missions
Apart from the Aditya L1 Mission by ISRO which is a sun-specific mission, other countries have also launched similar programs:
- NASA’s Parker Solar Probe
- NASA’s Living With a Star
- NASA’s Helios 2