|Mission type||Solar observation|
|Mission duration||5.2 years (planned) |
3 days (elapsed)
|Manufacturer||ISRO / IUCAA / IIA|
|Launch mass||1,475 kg (3,252 lb)|
|Payload mass||244 kg (538 lb)|
|Start of mission|
|Launch date||2 September 2023, 11:50 IST (06:20 UTC)|
|Launch site||Satish Dhawan Space Centre|
|Reference system||Sun–Earth L1|
|Epoch||January 2024 (planned)|
Aditya-L1 (from Sanskrit: Aditya, "Sun") is a coronagraphy spacecraft to study the solar atmosphere, designed and developed by the Indian Space Research Organisation (ISRO) and various other Indian research institutes. It will be inserted at about 1.5 million km from Earth in a halo orbit around the L1 Lagrange point between the Earth and the Sun where it will study the solar atmosphere, solar magnetic storms, and their impact on the environment around the Earth.
It is the first Indian mission dedicated to observing the Sun. Nigar Shaji is the project's director. It was launched aboard a PSLV-XL launch vehicle at 11:50 IST on 2nd September 2023, ten days after the successful landing of ISRO's moon mission, Chandrayaan 3. It successfully achieved its intended orbit nearly an hour later, and separated from the fourth stage at 12:57 IST.
Aditya-L1's main science objectives are:
Aditya was conceptualised in January 2008 by the Advisory Committee for Space Sciences (ADCOS). It was initially envisaged as a small 400 kg (880 lb), LEO (800 km) satellite with a coronagraph to study the solar corona. An experimental budget of ₹3 crore was allocated for the financial year 2016–2017. The scope of the mission has since been expanded and it is now planned to be a comprehensive solar and space environment observatory to be placed at Lagrange point L1, so the mission was renamed "Aditya-L1". As of July 2019[update], the mission has an allocated cost of ₹378 crores excluding launch costs.
"Aditya" is named after Surya and the Adityas, the revered Hindu deities representing the Sun. The "L1" designation denotes Lagrange point 1, signifying the precise location situated between the Sun and Earth where the Indian spacecraft is set to embark.
The Aditya-L1 mission will take around 109 Earth days after launch to reach the halo orbit around the L1 point, which is about 1,500,000 km (930,000 mi) from Earth. The spacecraft will remain in the halo orbit for its planned mission duration while being maintained at a stationkeeping cost of 0.2–4 m/s per year. The 1,500 kg (3,300 lb) satellite carries seven science payloads with diverse objectives, including but not limited to, coronal heating, solar wind acceleration, coronal magnetometry, origin and monitoring of near-UV solar radiation (which drives Earth's upper atmospheric dynamics and global climate), coupling of the solar photosphere to the chromosphere and corona, in-situ characterisations of the space environment around Earth by measuring energetic particle fluxes and magnetic fields of the solar wind, and solar magnetic storms that have adverse effects on space and ground-based technologies.
Aditya-L1 will be able to provide observations of the sun's photosphere, chromosphere and corona. In addition, an instrument will study the solar energetic particles' flux reaching the L1 orbit, while a magnetometer payload will measure the variation in magnetic field strength at the halo orbit around L1. These payloads have to be placed outside the interference from the Earth's magnetic field and hence could not have been useful in the low Earth orbit as proposed in the original Aditya mission concept.
One of the major unsolved issues in the field of solar physics is that the upper atmosphere of the Sun is 1,000,000 K (1,000,000 °C; 1,800,000 °F) whereas the lower atmosphere is just 6,000 K (5,730 °C; 10,340 °F). In addition, it is not understood how exactly the Sun's radiation affects the dynamics of the Earth's atmosphere on a shorter as well as a longer time scale. The mission will obtain near-simultaneous images of the different layers of the Sun's atmosphere, which will reveal the ways in which energy may be channeled and transferred from one layer to another. Thus, the Aditya-L1 mission will enable a comprehensive understanding of the dynamical processes of the Sun and address some of the outstanding problems in solar physics and heliophysics.
The instruments of Aditya-L1 are tuned to observe the solar atmosphere, mainly the chromosphere and corona. In-situ instruments will observe the local environment at L1. There are seven payloads on-board, with four for remote sensing of the Sun and three for in-situ observation. The payloads have been developed by different laboratories in the country with the close collaboration of various centres of ISRO.
|Remote Sensing Payloads||1||Visible Emission Line Coronagraph (VELC)||Corona/Imaging and spectroscopy||Indian Institute of Astrophysics, Bangalore|
|2||Solar Ultraviolet Imaging Telescope (SUIT)||Photosphere and chromosphere imaging- narrow and broadband||Inter University Centre for Astronomy & Astrophysics, Pune|
|3||Solar Low Energy X-ray Spectrometer (SoLEXS)||Soft X-ray spectrometer: Sun-as-a-star observation||U R Rao Satellite Centre, Bangalore|
|4||High Energy L1 Orbiting X-ray Spectrometer(HEL1OS)||Hard X-ray spectrometer: Sun-as-a-star observation|
|In-situ Payloads||5||Aditya Solar wind Particle Experiment (ASPEX)||Solar wind/Particle analyzer protons and heavier ions with directions||Physical Research Laboratory, Ahmedabad|
|6||Plasma Analyser Package For Aditya (PAPA)||Solar wind/Particle Analyzer Electrons and Heavier Ions with directions||Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram|
|7||Advanced Tri-axial High Resolution Digital Magnetometers||In-situ magnetic field (Bx, By and Bz).||Laboratory for Electro Optics Systems, Bangalore|
On September 2, 2023, at 11:50 IST, the Polar Satellite Launch Vehicle (PSLV-C57) accomplished the successful launch of the Aditya-L1 from the Second Launch Pad of the Satish Dhawan Space Centre (SDSC) located in Sriharikota.
The Aditya-L1, following a flight duration of 63 minutes and 20 seconds, achieved a successful injection into an elliptical orbit around the Earth at 12:54 IST.
The Aditya-L1 is scheduled to undergo a series of four Earth-bound orbital manoeuvres prior to its placement in the transfer orbit towards the Lagrange point L1. Aditya-L1 is projected to reach its designated orbit at the L1 point approximately 127 days following its launch.
On 3 September 2023 the Aditya-L1 performed its first Earth-bound maneuver, raising its orbit to a 245 km (152 mi) into 22,459 km (13,955 mi) orbit.
|Stage and Sequence||Date/Time||Time (IST)||Periapsis||Apoapsis||Orbital Period||References|
|Earth Orbit Insertion||2 September 2023||12:54 p.m||235 km (146 mi)||19,500 km (12,100 mi)|||
|Earth Bound Maneuver 1||3 September 2023||11:40 a.m.||245 km (152 mi)||22,459 km (13,955 mi)|||
|Earth Bound Maneuver 2
|5 September 2023||3:00 a.m|||
|Earth Bound Maneuver 3|
|Earth Bound Maneuver 4|
|Earth Bound Maneuver 5|
|Trans-Lagrangian 1 Injection|