The Indian government has approved the Indian Space Research Organisation’s first mission to study the sun. The Aditya-L1 mission is a seven-instrument satellite that will be launched in 2019 or 2020.
Possibly ISRO’s most challenging mission since its 2013 Mars Orbiter Mission, Aditya (Sanskrit for sun) was originally conceived in 2008 with the goal of observing the solar corona. The original mission consisted of a relatively small satellite in low Earth orbit, carrying a single coronagraph as its only scientific instrument.
The revised, more ambitious Aditya-L1 mission will use India’s Polar Satellite Launch Vehicle to loft the satellite 1.5 million kilometers above Earth to the L1 Lagrange point, a gravitationally stable position that will give Aditya-L1 a continuous view of the sun.
The satellite’s main payload, as in the original Aditya mission, will be the coronagraph, but it will carry six additional instruments with enhanced science scope and objectives.
One of those instruments, the Solar Ultraviolet Telescope (SUIT), will allow scientists to observe the sun’s photosphere and chromosphere in near ultraviolet wavelengths. “The sun has never been [observed] from space in this wavelength range,” said Durgesh Tripathi of Inter-University Centre for Astronomy & Astrophysics, where SUIT is being developed. “Using SUIT observations we shall also be able to shed light on the origin of energetic events occurring on the sun’s surface, such as flares and coronal mass ejections.”
The other instruments in the Aditya-L1 mission are:
Two detectors to study the composition and variations of the solar wind; A magnetometer to measure the magnitude and nature of the interplanetary magnetic field; Two X-ray spectrometers to study the solar corona’s heating mechanism and dynamic events.
Scientists hope that results from Aditya-L1 will solve the scientific mystery of how the corona gets heated to over a million degrees Kelvin, compared to the solar disc’s 6,000 degrees Kelvin.
Aditya-L1’s increase in number of instruments from the original Aditya mission plan corresponds to an increase in the diversity of its scientific goals.
According to ISRO, “the enhanced Aditya-L1 project will enable a comprehensive understanding of the dynamical processes of the sun and address some of the outstanding problems in solar physics,” an ambitious goal for India’s first solar mission.