Following the successful soft landing of Chandrayaan 3 near the Moon's south pole, the Indian Space Research Organisation (ISRO) is gearing up for the launch of its maiden solar mission 'Aditya L1'.
ISRO's Polar Satellite Launch Vehicle (PSLV) rocket spacecraft is set to take flight from Satish Dhawan Space Centre SHAR (SDSC SHAR), Sriharikota on September 2.
According to ISRO, the spacecraft will be placed in a halo orbit around the Lagrange point 1 (L1) of the Sun-Earth system, which is about 1.5 million km from the Earth to observe the solar activities and its effect on space weather in real-time. Here's all you need to know about India's sun mission.
What is Aditya L1?
Aditya L1 is the first Indian solar mission spacecraft designed and developed by ISRO and other Indian research institutes to study the sun. 'Aditya' stands for the Sun in Sanskrit while L1 refers to the Lagrange point 1 of the Sun-Earth system.
The spacecraft will be inserted into the halo orbit around the L1 point between the Earth and the Sun from where it can observe the Sun's activities without any occultation or eclipse.
According to ISRO, the spacecraft will carry payloads to observe the photosphere, chromosphere, and the outermost layers of the sun 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 and fields at the Lagrange point L1.
What is Lagrange point?
The Lagrange Points -- named after Italian-French mathematician Joseph-Louis Lagrange -- are positioned in space where the gravitational forces of the Sun and the Earth produce enhanced regions of attraction and repulsion.
They are also called points of equilibrium or libration points. There are a total of five Lagrange points denoted as L1, L2, L3, L4 and L5.
The Lagrange point (L1) is the position in space that is around 1.5 million kilometres from the Earth where the spacecraft will stay with reduced fuel consumption and remain in position.
According to ISRO, the gravitational pull of the two large bodies at the Lagrange point equals the necessary centripetal force required for a small object to move with them.
Trajectory of Aditya L1
As per ISRO, initially, the spacecraft will be placed in a Low Earth Orbit. Subsequently, the orbit will be made more elliptical and later the spacecraft will be launched towards the Lagrange point (L1) by using onboard propulsion.
As the spacecraft travels towards L1, it will exit the Earth’s 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 is expected to take about four months.
What are the objectives of the mission?
The ISRO has listed the following major science objectives of Aditya-L1 mission:
Why is Aditya L1 mission important?
Lying 93 million miles (150 million kilometres) away, the nearest and most dynamic star, the Sun constantly influence the Earth with its radiation, heat flow of particles and magnetic field.
The explosive solar phenomena could cause various disturbances near Earth's space environment disrupting various space and communication systems.
Therefore, a detailed study is of utmost importance to understand how exactly it affects the dynamics of Earth's atmosphere in shorter as well as longer terms.
This mission will help scientists understand the dynamic processes of the sun and can also solve some outstanding problems in solar physics and heliophysics (The physics of the sun and its connection with the solar system).
Why study the sun from space?
The protective shield and atmosphere of earth the block harmful radiations. hence, the instruments from Earth will not be able to detect the harmful radiations and its solar studies could not be carried out. Thus, studying from space is the best option.
Again, to understand how the solar wind particles and magnetic field from the sun travel through interplanetary space, the measurements are to be taken from a point away from the influence of the Earth's magnetic field.
Who developed Aditya-L1 and what is the cost of the mission?
In 2022, the Indian Space Agency designated a senior solar scientist at the U R Rao Satellite Centre (URSC), Bengaluru, Dr Sankarasubramanian K as the Principal Scientist of the 'Aditya-L1' Mission. The Science Working Group has members from several institutes in India engaged in solar science research. In 2019, the government had sanctioned the equivalent of about USD 46 million (nearly Rs. 380 crore) for the Aditya-L1 mission. But, the total cost of the mission is yet to be revealed.
Which other countries have launched solar missions?
So far, the US, Japan, China and the European Union have all launched probes to explore the Sun.
The National Aeronautics and Space Administration (NASA) — the United States' space research agency — launched the Parker Solar Probe (PSP) on August 12, 2018.
Parker's spacecraft became the closest ever artificial object to the Sun when it plunged into the star's outer atmosphere or corona, during its eighth flyby on April 28, 2021, according to NASA.
NASA's solar probe is expected to reach within about 4 million miles (6.5 million kilometres) of the Sun's surface to trace the flow of energy, to study the heating of the solar corona, and to explore what accelerates the solar wind.
PSP will keep drawing ever closer to the sun and diving deeper into the corona until its grand finale orbit in 2025. The probe will complete 24 orbits of the sun over its seven-year lifespan and will fly seven times closer to the star than any other spacecraft. The spacecraft, about the size of a small car, travels directly through the Sun's atmosphere, making it the first and only mission to do so.
China was the most recent country to launch a solar experiment. The Advanced Space-based Solar Observatory (ASO-S) was successfully launched by China's National Space Science Center (NSSC) on October 8, 2022. The ASO-S spacecraft — nicknamed Kuafu-1, will use three instruments to study the sun's magnetic field, solar flares and coronal mass ejections (CMEs).