From left: Dhiyanesh, Project Manager at Larsen and Toubro (L&T) industry partner; Nikhil Naik, TMT Production Support Engineer; Karthic Kumar, SSA Work Package Manager at the India TMT Coordination Center (ITCC); Selva Kumar, Assistant Manager - Quality at L&T and Ananthu C M, QA Engineer at ITCC. The TMT’s Segment Support Assemblies (SSA) seen in the picture were manufactured and assembled by L&T.
The first five TMT Segment Support Assembly (SSA) sets were manufactured and assembled at Larsen and Toubro (L&T) Coimbatore facility prior to be shipped to India’s TMT Optical Fabrication Facility (ITOFF).
TMT Segment Support Assemblies (SSA) are opto-mechanical systems that provide the support for each individual piece of mirror segment.
In March 2023, five TMT Segment Support Assemblies (SSA) were completed in Coimbatore, India, by the Larsen and Toubro (L&T) company. On the first row are Nikhil Naik, TMT Production Support Engineer, Karthic Kumar, SSA Work Package Manager at the India TMT Coordination Center (ITCC) and Eswar Reddy, ITCC Programme Director (respectively 8th, 5th and 7th from the left) posing with the L&T SSA production team and members of the ITCC group to commemorate the first five sets of SSA shipped to India’s TMT optics fabrication facility.
Overview showing WFOIS instrument ...
The Thirty Meter Telescope is shown oriented straight up to the zenith viewed from behind the telescope tube, the telescope tips away to the back of the image to lower elevations. The segmented primary mirror reflects some of the segment handling system and the four mirror cleaning arms can be seen around the circumference of the primary mirror. The two instrument platforms are seen with the light blue adaptive optics enclosure on the platform on the right of the image. Attached to top of the adaptive optics system is the MODHIS instrument on top, shown in dark blue, the IRIS instrument beneath, seen as gray, and on the side port is a commissioning instrument, also shown as gray. The tertiary mirror in the center of the primary mirror is oriented to send light to the Wide Field Optical Spectrograph, the light gray structure located on the instrument platform on the left side of the image. The foreground structure is part of the mirror segment handling system that transfers segments up and down to the observatory floor and on and off the segment handling system above the primary mirror. Segment exchanges take place with the telescope oriented to the zenith.
Stylized view of the Thirty Meter Telescope from above with the telescope tube structure suppressed to highlight instruments and the segment handling system. The two instrument platforms are shown on either side of the primary mirror. On the left side is the adaptive optics enclosure in blue and light gray supporting the hexagonal shaped MODHIS First Light instrument on top (also in blue). The charcoal colored structure immediately adjacent to the adaptive optics system is the telescope optics alignment and phasing system (APS). The tertiary mirror in the center of the primary mirror is oriented to send light to the Wide Field Optical Spectrograph, the light gray structure located on the instrument platform on the right. At the top of the image is the part of the mirror segment handling system that transfers segments up and down to the observatory floor and on and off the segment handling system above the primary mirror (not shown).
The Thirty Meter Telescope is shown at a very low elevation angle. The segmented primary mirror reflects the convex secondary mirror. The tertiary mirror in the center of the primary mirror is oriented to send light to the Wide Field Optical Spectrograph, the gray structure located on the right side of the image. The left and right instrument platforms are seen and the dark blue adaptive optics enclosure is seen on the upper left on the instrument support structure.
The telescope is shown from the NFIRAOS-IRIS Nasmyth platform in an inclined position, shooting its laser guide star towards a starry cloudless night sky. An orange light is still turned on within the enclosure to show the details of the telescope structure. The WFOS instrument (seeing-limited multi-object visible spectrograph) is shown across the primary mirror, sitting on the other Nasmyth platform. The enclosure cover can be seen across the dome, behind the rotating enclosure structure, in its fully retracted position, ready for astronomical observations.
The Thirty Meter Telescope is shown at an elevation angle of about 45 degrees. The segmented primary mirror reflects some of the telescope’s upper tube structure. The two instrument platforms are seen and the dark blue adaptive optics enclosure is seen in the foreground atop the instrument support structure. Attached to top of the adaptive optics system is the MODHIS instrument on top, shown in dark blue. The charcoal colored structure immediately alongside the adaptive optics system is the telescope optics alignment and phasing system (APS). The tertiary mirror in the center of the primary mirror is oriented to send light to the Wide Field Optical Spectrograph, the gray structure located on the instrument platform to the rear of the image.
Close view of the IRIS instrument attached to the NFIRAOS adaptive optics system. This image shows one of TMT Nasmyth platforms with the IRIS instrument, a first-light adaptive optics fed spectro-imager, attached below the (blue) enclosure of TMT’s adaptive optics facility NFIRAOS. IRIS cable wrap is the circular containment below IRIS, on the floor of the Nasmyth platform. IRIS is attached with supporting rods that are also used to absorb vibrations. The top part of IRIS hosts the instrument wavefront sensors, which work with NFIRAOS to further improve IRIS image quality. Below is attached the cryostat which cools the optical components of the imager (top) and spectrograph (bottom) at -200 deg. Celsius. NFIRAOS can hold up to three instruments and a first-decade AO-fed instrument, which is not yet selected but could be a near-infrared multi-object spectrograph, is seen attached on the side of NFIRAOS enclosure. Two day workers are shown near the instrument to provide a perception of the size of TMT instruments. The ventilation vents are opened and let the air and light enter the inside of TMT enclosure.
View of the telescope structure and mirrors through the enclosure opening. The inside of the dome is illuminated to show the opened ventilation vents on the side, one of the two Nasmyth platforms to the left, and the telescope in an inclined position with its primary, secondary and tertiary mirrors. The secondary mirror is seen in reflection on the primary mirror. The back of the secondary mirror shows the small launch telescope which is used to propagate the laser light to form an artificial laser guide star to be used for image correction by TMT’s adaptive optics system.
