Aditya-L1: PSLV-C57 Successfully Places India's First Sun Observatory In Low-Earth Orbit

The Indian Space Research Organisation (ISRO) successfully launched Aditya-L1, its first solar observatory, on September 2, 2023. The satellite was deployed into a low-Earth orbit by PSLV-C57, the 59th mission of the Polar Satellite Launch Vehicle.

Aditya-L1 will now embark on a journey of approximately 125 days to reach its ultimate destination: a halo orbit encircling Lagrange point 1 (L1). L1 is a gravitationally stable point located between the Sun and Earth, about 1.5 million kilometers from Earth.

From its vantage point at L1, Aditya-L1 will study the Sun's atmosphere, solar magnetic storms, and their impact on the environment around Earth. The satellite is equipped with a number of instruments, including a coronagraph, a spectrograph, and a magnetometer.

In the immediate future, Aditya-L1, positioned in low-Earth orbit, will undergo a series of orbit-raising maneuvers. Following each maneuver, the spacecraft's orbit will become increasingly elliptical compared to the previous one.

Upon completing three orbit-raising maneuvers, Aditya-L1 will escape Earth's gravitational sphere of influence, ushering in the cruise phase. This phase will guide Aditya-L1 along the trajectory leading to its insertion into the halo orbit.

Once situated within the halo orbit around L1, Aditya-L1 will assume a stable position, expending minimal fuel. This equilibrium arises as the centripetal force acting on it equals the gravitational forces exerted by both the Sun and Earth-a characteristic feature of Lagrange points. Furthermore, this unique position at L1 will grant Aditya-L1 an uninterrupted view of the Sun for a continuous span of five years.

Aditya-L1's primary mission objectives encompass the study of the solar corona, the underlying processes within this layer, the intricacies of coronal mass ejections, the dynamics of solar flares, and the influence of solar activities on space weather.

The observatory boasts a suite of seven payloads, comprising four remote sensing payloads and three in-situ payloads. The remote sensing payloads operate as spectrometers, while the in-situ payloads include two particle analyzers and a magnetometer.

Aditya-L1 will conduct simultaneous observations of the Sun in visible, X-ray, and ultraviolet wavelengths, enriching our understanding of solar phenomena.

Positioned at a distance of 1.5 million kilometers from Earth and 148.5 million kilometers from the Sun, Aditya-L1 stands poised to unravel the mysteries of our star and contribute valuable insights into solar science.