|Mission type||Solar observation|
|Mission duration||5 years (planned) |
|Manufacturer||ISRO / IUCAA / IIA|
|Launch mass||1,500 kilograms (3,300 lb) |
|Payload mass||244 kg (538 lb) (approx.) |
|Start of mission|
|Launch date||January 2022|
|Launch site||Satish Dhawan Space Centre|
|Reference system||Sun–Earth L1|
Aditya (Sanskrit: आदित्य, lit: Sun, pronunciation (help·info)) or Aditya-L1 is a spacecraft mission to study the Sun. It has been designed and will be built in collaboration between the Indian Space Research Organisation (ISRO) and various Indian research institutes. It is planned to be launched on the PSLV-C56 in December 2021 or January 2022. It is India's first solar mission.
Aditya was conceptualised in January 2008 by the Advisory Committee for Space Research. It was initially envisaged as a small 400 kg, low-Earth orbiting satellite with a coronagraph to study the solar corona. An experimental budget of 3 Crore INR 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 the Lagrangian point L1, so the mission was renamed "Aditya-L1". As of July 2019[update], the mission has an allocated cost of ₹378.53 crore excluding launch costs.
The Aditya-L1 mission will be inserted in a halo orbit around the L1 point, which is about 1.5 million km from Earth. The 1,500 kg satellite carries seven science payloads with diverse objectives, including but not limited to, the 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 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 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 on 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) hot 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 shorter as well as on longer time scale. The mission will obtain near simultaneous images of the different layers of the Sun's atmosphere, which reveal the ways in which the 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 satellite is planned to launched onboard PSLV-XL flight C56 in late 2021 or early 2022.