On 2nd September 2023, the Indian Space Research Organisation(ISRO) launched Aditya-L1(Lagrange Point 1), India’s 1st observatory-class space-based solar mission, launched by PSLV-C57 (Polar Satellite Launch Vehicle) rocket from the Second Launch Pad (SLP), Satish Dhawan Space Centre – SDSC (formerly Sriharikota Range – SHAR) in Sriharikota, Andhra Pradesh(AP).
- PSLV-C57 is the 59th flight of PSLV and the 25th mission using the PSLV-XL configuration.
About PSLV-C57/Aditya-L1 Mission:
Name significance: Aditya is the name of the Sun in Sanskrit language.
Objective: The PSLV-C57/Aditya-L1 Mission’s objective is to study the Sun, the nearest star and the largest object in the solar system, over the next 5 years.
i.The spacecraft is planned to be stationed in the halo orbit around the Lagrangian point 1 (L1) of the Sun-Earth system, which is about 1.5 million kilometres (km) from the Earth.
- The Aditya-L1 mission will take around 4 months to reach the designated point (L1) from where it will study the sun.
- The Aditya-L1 weighing about 1,4807.7 kg has successfully separated from the PSLV and began its 125-day journey towards L1.
ii.The spacecraft will perform orbital maneuvers using its Liquid Apogee Motor (LAM) to reach Sun-Earth L1.
iii.The Aditya-L1 will stay in the Earth-bound orbits for 16 days and undergo 5 maneuvers to gain the necessary velocity for its journey.
iv.Aditya-L1 will undergo a Trans-Lagrangian1 insertion maneuver and begin its 110 day trajectory to L1.
Mission Director: Nigar Shaji, an ISRO woman scientist from Tenkasi, Tamil Nadu is the Mission Director of the Aditya-L1 mission.
i.The satellite at the halo orbit around the L1 point will have the advantage of continuously viewing the sun without any occultation or eclipse.
ii.This will enable us to observe solar activities continuously.
- To study Coronal Heating and Solar Wind Acceleration.
- To understand the initiation of Coronal Mass Ejection (CME), flares and near-earth space weather.
- To understand the coupling and dynamics of the solar
- To understand solar wind distribution and temperature anisotropy.
i.This is the 1st spatially resolved solar disk in the near Ultra-Violet (UV) band.
ii.CME dynamics close to the solar disk (~ from 1.05 solar radius). This provides information in the acceleration regime of CME which is not observed consistently.
iii.On-board intelligence to detect CMEs and solar flares for optimised observations and data volume.
iv.Directional and energy anisotropy of solar wind using multi-direction observations.
The spacecraft carries seven payloads to observe the photosphere, chromosphere, and the outermost layers of the Sun (the corona) using electromagnetic and particle detectors.
- Visible Emission Line Coronagraph (VELC)
- Solar Ultra-violet Imaging Telescope (SUIT)
- Aditya Solar wind Particle EXperiment (ASPEX)
- Plasma Analyser Package for Aditya (PAPA)
- Solar Low Energy X-ray Spectrometer (SoLEXS)
- High Energy L1 Orbiting X-ray Spectrometer (HEL1OS)
Functions of the Payloads:
The science payloads of Aditya-L1 were indigenously developed by various laboratories across India.
i.VELC, developed at the Indian Institute of Astrophysics(IIA), Bengaluru, Karnataka, will study the solar corona and dynamics of Coronal Mass Ejections.
- VELC will send around 1140 images of the sun every day to the ground station.
ii.SUIT, developed at Inter-University Centre for Astronomy & Astrophysics(IUCAA), Pune, Maharashtra, will image the Solar Photosphere and Chromosphere in near UV and also measure the solar irradiance variations in near UV.
iii.APEX, developed at Physical Research Laboratory(PRL), Ahmedabad, Gujarat, and PAPA, developed at Space Physics Laboratory(SPL), Vikram Sarabhai Space Centre(VSSC), Thiruvananthapuram, Kerala, will study the solar wind and energetic ions, as well as their energy distribution.
iv.SoLEXS and HEL1OS, developed at U R Rao Satellite Centre, Bengaluru, and the Magnetometer payload at the Laboratory for Electro-Optics Systems, Bengaluru, will study the X-ray flares from the Sun over a wide X-ray energy range.
v.The Magnetometer will be used to measure the interplanetary magnetic fields at the L1 point.
These payloads were developed in close collaboration with ISRO centres.
Trajectory to L1:
Initially, the Aditya-L1 mission will be placed in low earth orbit.
The orbit will be made more elliptical and later the spacecraft will be launched towards L1 using onboard propulsion
About the Sun:
Estimated age: 4.5 billion years.
Distance from Earth to the sun: 150 million Km
The visible surface of the sun known as the photosphere is relatively cool and has a temperature of about 5,500 degrees Celsius.
i.The constant flow of particles from the sun is known as solar wind and is mostly composed of high-energy protons.
ii.The solar wind along with other explosive/ eruptive solar events like Coronal Mass Ejection (CME) affects the nature of space.
i.The Lagrange points are named after Joseph-Louis Lagrange, a French-Italian mathematician, who discovered their existence during his study of planetary physics in the 18th century.
ii.Lagrange points are imaginary points in space where objects sent there will stay put.
iii.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
iv.A total five Lagrange points denoted as L1, L2, L3, L4 and L5 are there.
With the launch of Aditya-L1, India joined the elite group that includes Japan, the United States of America (USA), Europe, and China which are studying the sun.
Recent Related News:
i.On July 14, 2023, the Indian Space Research Organisation (ISRO) successfully launched ‘Chandrayaan-3 (Moon Craft)’ spacecraft into orbit onboard Launch Vehicle Mark-3 Mission 4(LVM3 M4) rocket from SDSC SHAR (Satish Dhawan Space Centre- Sriharikota Range), Sriharikota, Andhra Pradesh (AP). Under the Chairmanship of ISRO Sreedhara Panicker Somanath.
ii.On 30th July 2023, Indian Space Research Organisation (ISRO) successfully launched the PSLV-C56/DS-SAR Mission, Polar Satellite Launch Vehicle (PSLV–C56) carrying 7 Singapore Satellites – DS-SAR as primary satellite along with 6 co-passengers, from the First Launch Pad (FLP) Satish Dhawan Space Centre (SDSC) in Sriharikota, Andhra Pradesh (AP).
About the Indian Space Research Organisation (ISRO):
Chairman– S. Somanath
Headquarters– Bengaluru, Karnataka