Tests over, India set to make the ‘iris’ of biggest telescope ever

[MehrotraPrince]

Tests over, India set to make the ‘iris’ of biggest telescope ever

Sometime in 2023, a 30-metre man-made "eye" will open atop the Hawaiian volcanic dome of Mauna Kea in search of life beyond the solar system. And India would have contributed its "iris".

Barely a month after signing in as a full partner in the $1.4 billion Thirty-Metre Telescope (TMT) project jointly developed by five nations, India is all set to make sensors and actuators that will keep the huge mirror of the biggest telescope in place.

"We have completed the tests. We are ready," said Indian Institute of Astrophysics (IIA) scientist B Eswar Reddy. IIA, Aryabhatta Institute of Observational Sciences (ARIES), Nainital and Inter-University Centre for Astronomy and Astrophysics (IUCAA) constitute the Indian arm of the consortium that also comprises labs from Canada, the US, China and Japan.

Edge sensors and actuators are crucial components of the telescope as the huge mirror is not a single piece, but a composite of 492 hexagonal segments. Each segment is controlled by three activators and two edge sensors along each inter-segment gap to ensure accurate optical images.

Eswar told the 102nd Indian Science Congress that India plays a pivotal role in setting up the telescope with a resolution 12 times better than that of the Hubble Space Telescope. "India will be involved in polishing the primary mirror and setting up its control system, besides developing electronics, edge sensors and actuators," Reddy said.


READ ALSO: India, 4 other nations to build world's biggest telescope

Stars in Southern Hemisphere night sky, looking towards centre of Milky Way. The centre of our galaxy (Milky Way) lies behind the dark dust clouds next to the lightest part of the Milky Way. (Getty Images photo)

The US will make the primary mirror segments, while China comes up with the tertiary mirror. Canada will put in place the dome and Japan the telescope structure.

TMT will strengthen the perennial search for intelligent life elsewhere, as it provides direct imaging of planetary systems. It will also help astronomers study planetary atmospheres, their origin and development.

While collaboration replaces competition as the mantra of astronomy and space science, India is a sought after partner. On top of the cosmic ventures, along with TMT, is the Square Kilometre Array (SKA), a next-generation radio telescope project in which India leads one of the nine packages.

(From right) The Nasa Infrared Telescope Facility, Keck I, Keck II, and Subaru Telescopes at the Mauna Kea Observatories, Mount Mauna Kea, Hawaii. The world's biggest telescope TMT will be built here. (Getty Images photo)

SKA will be 30 times more powerful than the best radio astronomy facility that exists today. Besides looking for extraterrestrial life, SKA hopes to help understand dark energy, sources of magnetic fields and the origin of stars and galaxies.

The Subaru Telescope at Mount Mauna Kea. (Getty Images photo)

"India is leading the work package involving the telescope's manager, which will effectively act as the telescope's brain or central nervous system," says Professor Yashwant Gupta, dean of the Giant Metrewave Radio Telescope (GMRT) located near Pune. GMRT has been designed and built by NCRA, a national centre of the Tata Institute of Fundamental Research.

Tests over, India set to make the ‘iris’ of biggest telescope ever - The Times of India

 

[MehrotraPrince]

India’s Role

Edge Sensors: Edge sensors are an important component of the TMT. They measure the
relative displacement, tip and tilt of the segments. Each segmented mirror will have 12 edge
sensors and in total 3,234 sensors for entire M1. The work to produce 25 prototype sensors has
already been initiated by TMT-India at General Optics Asia Limited (GOAL) Puducherry.

Actuators: In order to achieve very high spatial resolution as well as sensitivity, all the 492
hexagonal mirror segments of the TMT must be precisely positioned with respect to each other to
form a 30-meter hyperboloid primary mirror. The M1 control system (M1CS) performs this task,
with the help of actuators that correct for the segments’ tip-tilt and piston errors measured by
edge sensors. Each mirror segment will be driven by three actuators and altogether 1,476 actuators
are required to keep all the segments aligned. 10 such prototype actuators are under manufacture
at Avasarala Technologies Limited (ATL), Bangalore.

Segment Polishing: Providing primary mirror segments to the TMT is one of the major
goals of India-TMT. As a first step towards this, India has to demonstrate segment polishing
capability either using Stress Mirror Polishing (SMP) technique or CNC approach.

Observatory Control Software: The TMT observatory control software consists of a set of
software components that control the operations of the telescope, the mirrors, the telescope
dome or enclosure, and the various instruments. India is responsible for the Observatory Software
(OSW).
1. Event Services: Event Service is a software-only product that provides a highperformance publish and subscribe messaging infrastructure between the different
software components. Efforts to identify the software and an implementation scheme are
underway.
2. Generation of Infrared Guide Star Catalog: TMT instruments operating in the
infrared wavelength regime will be supported with AO system. In addition to the laser
guide stars, the observations with AO system also require natural guide stars. A catalog of
guide stars with their parameters to the required accuracy should be available before the
operation of TMT begins. Currently such a catalog in infrared does not exist. Institutes in
India are involved in the generation of this catalog. The initial phase of this process is
completed and the next phase has started.

please merge the threads, thank you @Oscar

 

[TimeTraveller]

Amazing .......