India’s first solar observatory mission — Aditya-L1 — was launched by the Indian Space Research Organisation (ISRO) on September 2, 2023.
Key points
- It took off from the Satish Dhawan Space Centre in Sriharikota onboard PSLV C-57. This was among the longest flights of ISRO’s workhorse launch vehicle in recent times.
- The spacecraft will be positioned within a ‘haloo orbit’ around Lagrange point 1 (L1) in the Sun-Earth system, located approximately 1.5 million km away from Earth. A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the Sun without any occultation/eclipses. This will provide a greater advantage of observing the solar activities and its effect on space weather in real time.
- Study will be conducted of Chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections and flares.
- Disturbances in the form of solar flares, Coronal Mass Ejection, or solar winds directed towards Earth, can adversely impact space weather; studying the Sun is, therefore, of paramount importance.
- Aditya-L1 has a mission life of five years.
- The seven payloads onboard Aditya-L1 are: Visible Emission Line Coronagraph (VELC); Solar Ultraviolet Imaging Telescope (SUIT); Solar Low Energy X-ray Spectrometer (SoLEXS); High Energy L1 Orbiting X-ray Spectrometer (HEL1OS); Aditya Solar wind Particle Experiment (ASPEX); Plasma Analyser Package For Aditya (PAPA); and Advanced Tri-axial High Resolution Digital Magnetometers.
- Aditya-L1 is also ISRO’s second astronomy observatory-class mission after AstroSat (2015).
- While AstroSat, India’s first dedicated astronomy mission aimed at studying celestial sources in X-ray, optical, and UV spectral bands simultaneously, remains operational almost eight years after its launch, Aditya-L1 can potentially pave the way for future Indian astronomy missions.
- A day after India’s first solar observatory mission which was launched, the first Earth-bound firing to raise the orbit of the Aditya-L1, was performed on September 3. The ISRO Telemetry, Tracking and Command Network Work (ISTRAC) in Bengaluru performed the manoeuvre.
- Subsequently, Aditya-L1 undergoes a Trans-Lagrangian1 insertion manoeuvre, marking the beginning of its 110-day trajectory to the destination around the L1 Lagrange point.
- Upon arrival at the L1 point, another manoeuvre binds Aditya-L1 to an orbit around L1, a balanced gravitational location between the Earth and the Sun.
- The satellite spends its whole mission life orbiting around L1 in an irregularly shaped orbit in a plane roughly perpendicular to the line joining the Earth and the Sun.
PSLV
- The solar probe was carried into space by the Polar Satellite Launch Vehicle (PSLV) in ‘XL’ configuration.
- PSLV is one of the most reliable and versatile workhorse rockets of ISRO. Previous missions like Chandrayaan-1 in 2008 and Mangalyaan in 2013 were also launched using PSLV.
- The rocket is most powerful in the ‘XL’ configuration as it is equipped with six extended strap-on boosters — they are larger than the boosters of other configurations and, therefore, can carry heavier payloads.
