Aditya-L1

Aditya-L1 was designed to study the Sun from space using both remote-sensing instruments and measurements made in the local environment. It launched aboard the Polar Satellite Launch Vehicle (PSLV-C57) on 2 September 2023. After a series of Earth-orbit manoeuvres and a cruise toward the Sun–Earth L1 region, the spacecraft entered its planned halo orbit on 6 January 2024. L1 is roughly 1.5 million kilometres from Earth in the direction of the Sun. A halo orbit there gives the observatory a near-continuous view of the Sun without Earth eclipses, while allowing it to sample solar-wind particles and magnetic fields before they reach Earth. The spacecraft does not travel to or land on the Sun.

The mission carries seven scientific payloads. Four remotely observe the Sun: the Visible Emission Line Coronagraph (VELC) studies the corona; the Solar Ultraviolet Imaging Telescope (SUIT) images the photosphere and chromosphere; and the SoLEXS and HEL1OS instruments measure soft and hard X-rays. Three in-situ payloads—ASPEX, PAPA and a set of high-resolution magnetometers—measure solar-wind particles and magnetic fields near L1. Together these instruments examine different parts of the solar atmosphere and the material and fields flowing through interplanetary space.

The scientific programme includes investigating coronal heating, solar flares and coronal mass ejections (CMEs), the structure and dynamics of the corona, and the origin and evolution of the solar wind. Observations from Aditya-L1 can also help scientists study how solar eruptions propagate and interact with Earth's environment. India's Department of Space has reported results including observations of the onset of a CME and high-resolution near-ultraviolet views of solar flares; findings are reported in peer-reviewed journals. The mission is a solar-physics observatory, not itself a dedicated operational space-weather forecasting mission, although its observations contribute to understanding processes relevant to space weather.

Aditya-L1 is India's first dedicated space-based solar observatory and a long-duration platform for coordinated measurements of the Sun and the solar wind. Its location and combination of remote and in-situ instruments allow researchers to connect activity in the solar atmosphere with particles and magnetic fields measured farther out. The resulting observations complement ground-based solar monitoring and data from other solar missions.