Bengaluru to crack giant mirror conundrum for Hawaii telescope

by news
•
March 25, 2015

Bengaluru: The hugely anticipated Thirty Meter Telescope (TMT) coming up in Hawaii, with the promise of enabling astronomers to gaze 13 billion light years into the universe, poses a formidable conundrum: How do you make 492 mirrors behave like a single, gigantic 30 metre-wide surface? The answer to this will come all the way across the globe, from Bengaluru.

An artist’s concept of the Thirty Meter Telescope, which is coming up in Hawaii, at night.

The “trickiest part” is to get hundreds of segments behave like a gigantic monolithic mirror and this involves developing several new technologies in mechanics, electronics, optics and control software, said Eswar Reddy, programme director of TMT-India and associate professor at the Indian Institute of Astrophysics.
Hundreds of segments

The primary TMT mirror comprises of hundreds of hexagonal segments of 1.44 metres each and that if the segments move they send out signals and can be brought back to their original place.

This is required because it is impossible to create a single, workable 30-metre diameter mirror. Prof. Reddy said, “It will be too heavy and will eventually sag from gravity.” As many as 1,500 actuators, which sense and correct any segment displacement even to an extent of a micron, will be fabricated by a Bengaluru-based company as well. This apart, the segment support assembly to keep them as a single mirror of hyperboloid shape will also be made in the city.
Partnership

While India officially signed as a partner for the TMT project along with the U.S., Japan, Canada and China on Tuesday, Bengaluru’s expertise in astrophysics, electronics and software development will be put to test in this project. The TMT, which is expected to be completed in 2023, will be 150 times more powerful than the Hubble Space Telescope, allowing astronomers to look well beyond our solar system, to the near-beginning of time. “We will be able to observe the universe when it was very young, just half a million light years,” Prof. Reddy said.

Beside the IIA, Aryabhatta Research Institute for Observational Sciences (Nainital) and the Inter-University Centre for Astronomy and Astrophysics (Pune) constitute TMT-India.