Aditya-L1 — India's First Solar Observatory
India's first dedicated space-based solar observatory, Aditya-L1, successfully entered a halo orbit around the Sun–Earth L1 Lagrange point on 6 January 2024, approximately 1.5 million kilometres from Earth. From this unique location, Aditya-L1 can continuously observe the Sun without the regular eclipses or occultations experienced by Earth-orbiting spacecraft. Carrying seven indigenously developed scientific payloads, the mission studies the Sun's photosphere, chromosphere, corona, solar wind, energetic particles and magnetic environment, helping scientists better understand solar eruptions and space weather that can affect satellites, communications, navigation systems and power infrastructure on Earth. Since reaching L1, Aditya-L1 has produced significant scientific observations, including unprecedented near-ultraviolet observations of solar flare activity, while its scientific datasets have been made available to researchers in India and around the world.
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Timeline
1 January 2008
Aditya solar mission concept takes shape
India began developing the concept of a dedicated spacecraft for studying the Sun. The original Aditya mission was envisioned as a smaller satellite focused primarily on observing the solar corona.
1 January 2015
Mission expands into Aditya-L1
The original Aditya concept evolved into the much more capable Aditya-L1 mission, designed to operate around the Sun–Earth L1 point and carry multiple instruments for comprehensive observations of the Sun and the space environment.
2 September 2023
Aditya-L1 successfully launched
PSLV-C57 successfully launched Aditya-L1 from the Second Launch Pad at Satish Dhawan Space Centre, Sriharikota, at 11:50 IST. The spacecraft was initially placed into an elliptical Earth orbit of approximately 235 by 19,500 kilometres.
2 September 2023
India's first dedicated solar mission begins
The successful launch began India's first dedicated space-based mission for studying the Sun, carrying seven scientific payloads developed indigenously by ISRO and Indian research institutions.
3 September 2023
Earth-bound orbital manoeuvres begin
ISRO began a sequence of Earth-bound orbital manoeuvres to progressively increase Aditya-L1's orbit and prepare the spacecraft for its journey toward the Sun–Earth L1 point.
19 September 2023
Aditya-L1 begins journey toward L1
ISRO successfully performed the Trans-Lagrangian Point 1 Insertion manoeuvre, sending Aditya-L1 away from Earth and onto its approximately 110-day trajectory toward the Sun–Earth L1 region.
30 September 2023
Aditya-L1 escapes Earth's sphere of influence
Aditya-L1 travelled beyond Earth's sphere of influence during its journey toward L1, marking another milestone in India's operation of spacecraft beyond the immediate gravitational dominance of Earth.
6 October 2023
Trajectory correction successfully performed
ISRO performed a trajectory correction manoeuvre lasting approximately 16 seconds to fine-tune Aditya-L1's path toward its intended halo orbit around L1.
7 November 2023
HEL1OS detects first high-energy solar flare
The High Energy L1 Orbiting X-ray Spectrometer onboard Aditya-L1 captured its first high-energy X-ray observations of solar flares during the spacecraft's journey toward L1.
1 December 2023
Solar wind instrument becomes operational
The Solar Wind Ion Spectrometer within the Aditya Solar Wind Particle Experiment became operational and began measuring solar-wind ions, demonstrating the performance of the spacecraft's in-situ instruments.
8 December 2023
SUIT captures full-disk ultraviolet images of the Sun
The Solar Ultraviolet Imaging Telescope captured full-disk images of the Sun in near-ultraviolet wavelengths, demonstrating one of Aditya-L1's major remote-sensing capabilities.
6 January 2024
Aditya-L1 successfully enters halo orbit
ISRO successfully inserted Aditya-L1 into its designated halo orbit around the Sun–Earth L1 point at approximately 16:00 IST. The spacecraft reached its operational destination roughly 1.5 million kilometres from Earth.
6 January 2024
India establishes its first space-based solar observatory
With Aditya-L1 reaching its operational halo orbit, India established its first dedicated space-based solar observatory capable of continuously studying the Sun from the Sun–Earth L1 region.
6 January 2024
Continuous unobstructed observation of the Sun enabled
Aditya-L1's halo orbit around L1 provides a continuous view of the Sun without regular occultations or eclipses, allowing sustained monitoring of solar activity and space-weather phenomena.
25 January 2024
Magnetometer boom successfully deployed
Aditya-L1 successfully deployed its six-metre magnetometer boom in halo orbit, allowing sensitive measurements of the interplanetary magnetic field while reducing interference from the spacecraft itself.
22 February 2024
SUIT observes powerful X6.3 solar flare
The Solar Ultraviolet Imaging Telescope observed an X6.3-class solar flare and captured unprecedented near-ultraviolet details of the flare's bright kernel in the lower solar atmosphere.
2 July 2024
Aditya-L1 completes first halo orbit
Aditya-L1 completed its first revolution around the Sun–Earth L1 point, demonstrating successful long-duration navigation and station-keeping in its approximately 178-day halo orbit.
1 December 2024
Aditya-L1 studies coronal mass ejection
Scientists using the Visible Emission Line Coronagraph onboard Aditya-L1 analysed a coronal mass ejection, demonstrating the observatory's ability to study solar eruptions relevant to understanding space weather.
6 January 2025
First Aditya-L1 scientific datasets released globally
On the first anniversary of halo-orbit insertion, ISRO released the first set of scientific data from all seven Aditya-L1 experiments to the global scientific community.
14 February 2025
Second Aditya-L1 science dataset released
ISRO released a second set of scientific data covering observations of the Sun's photosphere, chromosphere and corona together with in-situ particle and magnetic-field measurements from L1.
28 February 2025
Aditya-L1 produces historic solar-flare observation
ISRO announced that SUIT had captured the first-ever image of a solar-flare kernel in the lower solar atmosphere in near-ultraviolet wavelengths, providing new information about energy propagation during powerful solar eruptions.
14 May 2025
Rare plasma ejection observed in ultraviolet light
ISRO reported observations by SUIT of a powerful solar flare and a rare plasma ejection in ultraviolet light, further demonstrating Aditya-L1's ability to investigate explosive solar phenomena.
1 July 2026
Aditya-L1 develops into an international scientific observatory
Aditya-L1 continued regular observations from L1 and made its scientific data available for research. Government reporting stated that more than 27 terabytes of solar observation data had been disseminated, strengthening India's contribution to international solar and space-weather research.