ISRO planning to launch satellite to study the sun

100-kg ‘Aditya’ should be up in space by 2012 to study the dynamic solar corona, the outermost region of the sun.

Bangalore: In the midst of the buzz about Chandrayaan, the moon mission, the Indian Space Research Organisation (ISRO) is planning to launch a satellite to study the sun.

‘Aditya’ should be up in space by 2012 to study the dynamic solar corona, the outermost region of the sun. This fiery region has temperatures of over one million degrees, with raging solar winds that reach a velocity of up to 1000 km a second. The satellite will carry as its payload an advanced solar coronagraph.

“Aditya will be a small satellite weighing 100 kg, placed most likely in a near-earth orbit of 600 km,” said G. Madhavan Nair, Chairman, ISRO. “The satellite is intended to study one of the most fundamental problems of coronal heating, and other phenomena that take place in the magnetosphere. “This will be one of the first projects scheduled in a road map formulated by the Advisory Committee for Space Research, said Mr. Nair.

Beyond being a research exercise, Aditya has a unique practical application: to protect ISRO’s satellites from the vagaries of solar phenomena, said R. Sridharan, Programme Director, Space Science Office, ISRO.

“The sun’s corona is highly active, releasing energy during solar flares in the form of bursts — manifesting as geomagnetic storms on earth. These associated charged particles can distort the earth’s magnetic field, and have a huge bearing on near-earth space where our satellites are located,” he explained.

The launch of Aditya will coincide with a ‘solar maximum’ a phase of high solar dynamism, which will occur in 2012, said Prof. Sridharan.

“The sun goes through an 11-year cycle of activity — we crossed the solar minimum in 2006,” he said. The coronagraph will study the solar corona through an artificial eclipse that will prevent sunlight from directly entering the instrument, revealing to the telescope only the halo of the corona.

The advisory committee has constituted a national-level study group to work out the optimum configuration for the coronagraph, among other parameters.

The study group comprises individuals from the ISRO Satellite Centre, Udaipur Solar Observatory, Indian Institute of Astrophysics, Radio Astronomy Centre, National Centre for Radio Astrophysics, and several universities, said Prof. Sridharan. Their report will be out by May, and the project finalised by the end of 2008, he added. The projected cost of the satellite is approximately Rs. 50 crore.

“We want to cut costs by avoiding a dedicated launch. With ISRO’s multiple launching capability, Aditya could go as a co-passenger in one of the many launches scheduled for the next four years,” said Prof. Sridharan. “The cost of the instrument can also be reduced by nearly a factor of 10 by using screened industrial grade components. We do not need this satellite for more than two years — it would have gathered an enormous amount of data in this span of time.”