Thirty Meter Telescope

A new window to the universe


Our view of the universe was largely constrained to the unaided vision of our eyes before Galileo Galilei first adapted a telescope to look at the skies over four hundred years ago. Telescopes built till today have led to many fascinating and intriguing discoveries in astronomy, like the discovery of planets around other stars, evidence of accelerating expansion of the universe, existence of dark matter and dark energy, monitoring of asteroids/comets that could pose a serious threat to the inhabitants of the Earth. To maintain this exciting pace of discovery, astronomers and engineers are pushing the boundaries of today’s technology while simultaneously creating the innovations that will make the upcoming Thirty Meter Telescope (TMT) one of the world’s most advanced and capable ground-based optical and infrared observatory.

The TMT is being built by an international consortia of scientific institutes and organizations in Canada, China, India, Japan and the USA. In India, to efficiently manage India’s contributions the Department of Science & Technology (DST) and the Department of Atomic Energy (DAE), Government of India jointly formed India-TMT Coordination Centre (ITCC) located at the Indian Institute of Astrophysics (IIA).

TMT will integrate the latest innovations in technology: at the heart of the telescope is the segmented mirror, made up of 492 individual hexagonal segments which will work as a single reflective surface of 30m diameter providing unprecedented light gathering capability which will be nine times better the light gathering capacity of the most powerful current telescopes (like 10-m Keck telescope) and an advanced adaptive optics (AO) system which will provide superbly high resolution images ten times sharper than the Hubble Space telescope.

India’s in-kind contribution to the TMT project includes Mirror Segment polishing (SP), Segment Support Assemblies (SSA), Actuators, Edge Sensors, Software development for the observatory and design/development of science instruments. TMT enabled with these technologies will make ground breaking advances in a wide range of scientific areas.

Using the TMT, astronomers will be able to see further into our universe and reach back toward the very beginning of time. In the nearby universe, with the TMT, astronomers will be able to discover and characterize, in detail, planets orbiting stars other than the Sun. There is the potential to examine these planets for signs of life beyond the Earth: this would be one of the most important discoveries of all time. TMT will enable discoveries that we cannot even begin to anticipate today.

Technologies Developed


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 Primary Mirror control system (M1CS) performs this task with the help of nanometric positioning actuators that correct for the segments’ tip-tilt and piston errors, measured by edge sensors. India-TMT is responsible for the manufacturing of all the 1526 actuators required for the project. 20 prototype actuators were successfully fabricated and tested at 4 Indian industries (Southern Electronics Pvt Ltd., Bengaluru., Indo Danish Tool Room, Jamshedpur., Tamboli Engineers, Pune., Amado Tools, Bengaluru.), and currently they are undergoing lifetime test at Jet Propulsion Laboratory (JPL), USA.

Edge Sensors

Edge sensor is an essential component of the TMT M1CS. It measures the relative displacement, tip and tilt of the segments, which in turn will be corrected by the actuators. India-TMT will provide 3284 edge sensors required for M1CS. General Optics Asia Ltd (GOAL), Puducherry manufactured 12 capacitive edge sensor prototypes for India-TMT. These have successfully gone through the detailed testing at the Jet Propulsion Laboratory (JPL, USA).

Segment Support Assembly (SSA)

Each of the TMT primary mirror segments has to be mounted on a Segment Support Assembly (SSA). SSA comprises a number of critical components which require a rigorous process development for manufacturing as well as inspection. India-TMT will deliver all the 580 SSAs to the project. 6 prototype SSAs were manufactured at 2 Indian industries (Avasarala Technologies Limited, Bengaluru., and Godrej, Mumbai.), to realize the design as well as to develop the manufacturing methodology. These SSAs were then assembled and tested at TMT Project Office, Pasadena, USA. Now, ITCC has placed a contract for manufacturing and assembling of 100 nos. of SSA with Larsen and Toubro (L&T, Coimbatore).

Mirror Segment Fabrication Facility and Buyoff station

India-TMT is responsible for the fabrication of 84 primary mirror segments. A special facility, India-TMT Optics Fabrication Facility (ITOFF), is constructed at CREST campus of Indian Institute of Astrophysics (IIA), in Hoskote, Bengaluru for this purpose. A Buyoff station is highly essential during mirror manufacturing and metrology to provide stress free support for the mirror segments. Design and development of Buyoff station is done by India-TMT.

Central Diaphragm

Central diaphragm is a crucial interface between SSA and mirror segment. It provides lateral support to the mirror segment. India-TMT has successfully fabricated a very thin Central diaphragm, made of Invar material, down to the required stringent dimension and tolerance specifications


India-TMT is responsible for developing and delivering some of the principal software systems like the Observatory software (OSW) and the Telescope Control Software. OSW provides the software architecture support and infrastructure that integrates all TMT software to form one cohesive system. Telescope Control Software is responsible for the coordination and control of the various subsystems that make up the telescope, it also provides high-level control of the mount, the mirrors, and the enclosure, etc. Thoughtworks and Honeywell software companies, Pune, are contributing to these two major activities. Inspired by working with the India-TMT, ThoughtWorks have started a wing called E4R (engineering for research), and are keen to get involved in more Mega Projects

Science Instruments

The TMT will host a set of back-end instruments for science observations like Wide Field Optical Spectrograph (WFOS) and Infra-Red Imaging Spectrograph (IRIS) on first light. India is responsible for the end-to-end performance analysis of the optics design and software development for WFOS. India is also leading country for the development of the second generation instrument called High Resolution Optical Spectrograph (HROS). All the near Infra-red back-end instruments will be assisted by a Mulit-Conjugate Adaptive Optics (MCAO) system called Near Field Infra-Red Adaptive Optics System (NFIRAOS). A Near-InfraRed catalogue of stars is highly essential to perform atmospheric turbulence corrections by NFIRAOS and India-TMT is leading the creation of the final catalogue.

Co-ordinating Institutes in India

  • Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital

  • Indian Institute of Astrophysics (IIA), Bengaluru

  • Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune

Indian Industry / Institute Partners

  • Accurate Engineering Company Pvt. Ltd., Pune.

  • Amado Tools, Bengaluru.

  • Avasarala Technologies Limited, Bengaluru.

  • Center for Development of Advanced Computing, Bengaluru.

  • Central Manufacturing Technology Institute, Bengaluru.

  • Central Tool Room & Training Centre (CTTC), Bhubaneswar.

  • Delhi University, New Delhi.

  • Elite Metrology, Bengaluru.

  • Future Tech engineering Pvt Ltd, Bengaluru.

  • General Optics (Asia) Limited (GOAL), Pondicherry

  • Godrej, Mumbai.

  • Honeywell Automation India Limited, Pune.

  • Indo Danish Tool Room, Jamshedpur.

  • Indian Institute of Science, Bengaluru.

  • Indian Institute of Space Science and Technology, Thiruvananthapuram.

  • International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad.

  • IPA Private Limited, Bengaluru.

  • Lakshmi Tech & Engineering Industries Ltd., Coimbatore.

  • Larsen & Toubro, Coimbatore.

  • Magma Machining Pvt. Ltd., Ahmedabad.

  • Mechvac India Ltd., Mumbai.

  • National Aerospace Laboratories, Bengaluru.

  • National Centre for Aerospace Innovation and Research, IIT, Mumbai.

  • Nucon Aerospace Private Limited, Hyderabad.

  • Optics and Allied Engineering Pvt. Ltd., Bengaluru.

  • Plan Measuring Services, Bengaluru.

  • Physical Research Laboratory, Ahmedabad.

  • Pt. Ravishankar Shukla University, Raipur.

  • Raja Ramanna Centre for Advanced Technology, Indore.

  • Sahajanand Laser Technology Ltd., Ahmedabad.

  • SGS India Private Limited, Bengaluru.

  • Silvergrey Engineers, Bengaluru.

  • Southern Electronics Pvt. Ltd., Bengaluru.

  • Tata Institute of Fundamental Research (TIFR), Mumbai.

  • Tamboli Engineers Pvt. Ltd., Pune.

  • Tejpur University, Tejpur.

  • Techno Tools Precision Engineering, Bengaluru.

  • ThoughtWorks Technologies, Pune.

  • TÜV Rheinland, Bengaluru.


1. What is TMT?

The Thirty Meter Telescope (TMT) will be the world’s most advanced and capable ground-based optical, near-infrared, and mid-infrared observatory. It will integrate the latest innovations in precision control, segmented mirror design, and adaptive optics. At the heart of the telescope is the segmented mirror, made up of 492 individual segments. Precisely aligned, these segments will work as a single reflective surface of 30m diameter providing unprecedented light gathering capability. Assisted by advanced AO system, TMT will provide extremely high resolution images of the celestial objects. These capabilities will enable ground-breaking advances in a wide range of scientific areas starting from our own Solar system to the most distant parts of the Universe. Most importantly, several unanticipated and fundamental discoveries made by TMT will help shape the course of future research in astronomy. In short, TMT will be a leading next generation telescope posited to serve the world-wide astronomy community as a flagship research facility.

2. Why is the size of the thirty meter telescope important?

The purpose of the TMT is to further our knowledge and science of the Universe. The larger the diameter of the telescope, the greater the ability to collect light and greater the resolution to see details across the Universe. The resolution of TMT will be 10 times better than the Hubble Space Telescope and 3 times better than the current 10-m Keck telescope. From the previous generations of 8–10 meter class telescopes, it is a giant leap in sensitivity or image depth (81 times when compared to present day10-m Keck) that will allow astronomers to see much fainter and more distant objects that will enable to study them in greater detail.

3. What is presently the largest telescopes in India?

Among several optical telescopes in India, the 3.6 m Devasthal Optical Telescope located in Uttarakhand is the largest in the country.

4. How will TMT will be superior to existing telescopes?

TMT will have unprecedented light collection area, coupled with diffraction-limited spatial resolution that exceeds Keck (10-m telescope) by a factor of 3. Relative to the Hubble Space Telescope, TMT will have 144 times the collecting area and more than 10 times the spatial resolution at near-infrared and longer wavelengths.

5. Which is the present site chosen for hosting TMT?

TMT International Observatory (TIO) Corporation selected Maunakea, in Hawaii, as the preferred site to build and operate TMT.

6. When did India join the TMT project and what is the nature of participation?

India joined the Thirty Meter Telescope (TMT) project in 2014. The TMT project is an international partnership between Caltech, Universities of California, Canada, Japan, China and India. The Aryabhatta Research Institute for Observational Sciences (ARIES), Nainital; the Indian Institute of Astrophysics (IIA), Bangalore and the Inter-University Center for Astronomy and Astrophysics (IUCAA), Pune are the three main institutes spearheading the efforts of India-TMT. The activities of India-TMT are coordinated by the India-TMT Coordination Centre (ITCC) set up by the Department of Science and Technology, with IIA as the nodal agency of ITCC. India-TMT is jointly funded by the Department of Science & Technology (DST) and the Department of Atomic Energy (DAE), Government of India.

7. Which are the participating countries involved in TMT project?

Institutions in Canada, China, India, Japan and the USA.

8. When will the construction of TMT start and complete?

On-site construction is expected to start in 2019 and first light to be achieved by 2029-'30.

9. What is the total cost of TMT project and how much is the Indian contribution to TMT project in ‘Cash’ and ‘in-kind’?

The total estimated cost of TMT (base year 2012) is $1.4 billion USD. India’s contribution is 10%, out of which 30% is in ‘cash’ and 70% is ‘in-kind’.

10. What ‘in-kind’ items are to be contributed by India?

As a part of India’s in-kind contribution to the project, TMT-India is contributing components related to the primary mirror segments and control systems. It includes Edge Sensors, Actuators, Segment Support Assemblies (SSAs), segment polishing, science instruments, and software.

Connect with Us

Contact Person

India-TMT Coordination Center (ITCC),
Indian Institute of Astrophysics
2nd Block, Koramangala, Sarjapur Rd.

Phone: 080 - 2254 1307