India successfully launches Aditya-L1, its pioneering solar research mission, on board PSLV

India’s space program achieved another milestone with the launch of its first solar research mission, Aditya-L1, on Saturday. The Indian Space Research Organisation (ISRO) successfully launched the mission aboard the Polar Satellite Launch Vehicle (PSLV) XL rocket from the Satish Dhawan Space Centre. Aditya-L1 is dedicated to studying the Sun and will be the first Indian spacecraft to operate at the Earth-Sun L1 Lagrange point.

The main objectives of the Aditya-L1 mission are to increase understanding of coronal heating, study how the corona accelerates the solar wind, and investigate the initiation of solar flares and coronal mass ejections. The mission also aims to study the dynamics of the Sun’s atmosphere and monitor the distribution and anisotropy of particles in the solar wind.

The Aditya-L1 spacecraft carries a suite of seven instruments to study the Sun. The Visible Emission Line Coronagraph, built by the Indian Institute of Astrophysics, will observe the corona and coronal mass ejection events. The Solar Ultraviolet Imaging Telescope, developed by the Inter-University Centre for Astronomy and Astrophysics, will make observations of the full disc of the Sun at near-ultraviolet wavelengths. ISRO’s U R Rao Satellite Centre has contributed two x-ray imaging payloads, the Solar Low Energy X-ray Spectrometer and the High Energy L1 Orbiting X-ray Spectrometer, to study solar flares. The Aditya Solar Wind Particle Experiment, built by the Physical Research Laboratory, will study the solar wind using two sensors. The Plasma Analyser Package for Aditya, developed by the Vikram Sarabhai Space Centre’s Space Physics Laboratory, will contribute to studying the solar wind by recording the flux, density, and composition of electrons and ions. The Magnetometer will measure the magnetic fields in situ at the spacecraft’s location.

The launch of Aditya-L1 comes just ten days after ISRO achieved another major milestone with the successful landing of its Vikram probe on the Moon as part of the Chandrayaan-3 mission. With the agency’s recent successful launches and upcoming missions, including the first uncrewed test flight of its Gaganyaan crew capsule in early 2024, India’s space program is entering an important phase.

To reach its destination, Aditya-L1 was initially placed in a low-Earth orbit using the PSLV rocket and will perform a series of maneuvers to position itself at the Earth-Sun L1 Lagrange point. This point, located 1.5 million kilometers from Earth, ensures uninterrupted views of the Sun while remaining close enough for communication and data downlink.

Once Aditya-L1 reaches the Lagrange point, it will join four other spacecraft currently operating there: the Solar and Heliospheric Observatory, Advanced Composition Explorer, Wind missions, and the Deep Space Climate Observatory. Aditya-L1 is expected to reach its final orbit around the Lagrange point approximately 125 days after launch.

The PSLV rocket, specifically the PSLV-XL version, was used to deploy Aditya-L1. This four-stage launch vehicle has both solid and liquid-fueled propulsion and can place payloads of up to 1,750 kilograms into orbit. The rocket employed for this mission was designated as PSLV C57 and has a successful track record, with 55 successful missions prior to this launch.

The launch took place from the Second Launch Pad at the Satish Dhawan Space Centre on Sriharikota, an island in the Bay of Bengal. This launch pad has been used for PSLV, Geosynchronous Satellite Launch Vehicle, and GSLV Mk.III launches. It is one of two pads available for PSLV missions, with the SDSC being the site for all of India’s orbital launches so far.

The PSLV rocket’s first stage is powered by an S-138 solid rocket motor, which can be augmented by up to six PS0M-XL solid rocket boosters. The rocket’s second stage, designated PS2 or PL40, uses a single Vikas engine burning hypergolic liquid propellants. The third stage, HPS3, is a solid-fueled stage consisting of an S-7 motor. After the third stage burnout, the fourth stage, PS4, takes over and completes the insertion of Aditya-L1 into its initial orbit.

India’s launch of Aditya-L1 marks a significant step forward in its space program. With its focus on solar research and the deployment of advanced instruments, this mission will contribute to global understanding of the Sun and its various phenomena. As India continues to make strides in space exploration, it solidifies its position as a key player in the field.