The TMT primary mirror is segmented comprising a total of 492 hexagonal segments, each about 1.44 meters (56.6 inches) across corners. The segments fit very closely together, and are spaced with gaps of only 2.5 mm (0.1 inch).
TMT optics and system engineers and international review committee photographed at TMT’s headquarters in Pasadena on July 26, 2018 during M1S Final Design Review.
TMT member NAOJ with their industrial partners Canon Inc. and SHIBA R&D CO. Ltd. successfully performed hexagonal cutting of a full size primary mirror segment. Metrology measurements carried out by Coordinate Measurement Machines (CMM) show that critical dimensions of parts including pockets for sensors and actuators, meet TMT stringent requirements.
Dewars of liquid nitrogen (LN2) installed on the two Nasmyth platforms provide each TMT instrument’s cooling needs and maintain a steady state of cooling for all instruments. The total wet mass (including full cryogen load) of the CRYO components on each Nasmyth platform shall be less than 3,000 kg.
Space is available for supply and installation of additional CRYO equipment at first decade. The CRYO system shall occupy no more than 27m2 (TBC) of floor area in the utility room of the summit facilities.
Engineers from TMT project office were happy to welcome TMT International Observatory (TIO) Board Members at their technical laboratory near Pasadena. The visit was organized over the course of TIO Board of Directors meeting on Tuesday 31 July 2018. This was a unique opportunity to present the multi segment integration and test facility that will be used to verify and test all TMT primary mirror system components and assemblies prior to full-scale production. TIO Board Members are pictured in front of the primary mirror cell prototype that will host seven full size segments to verify the performance and operation of the primary mirror control system.
Mockup of the high pressure CO2 cable wrap at the TMT technical laboratory. Thomas Chylek, TMT opto-mechanical engineer (seen from the back) is holding a CO2 gun to demonstrate the testing of the cleaning process that will be used to drive any dust particle off the TMT mirror surfaces (primary, secondary and tertiary mirrors).
Glen Cole, TMT lead optical fabrication engineer, explains the technical steps involved in the integration of the glass segment with the new segment support design, prior to carrying out the optical test validation. The assembly tool is seen in the background. TIO Board members are looking over the safety perimeter of the spherical segment, which is guarded under a piece of protective black foam.
Alastair Heptonstall, TMT opto-mechanical engineer, is testing the guide flexure of the M1 segment to measure the component stiffness. Each TMT individual segment must be controlled to create a continuous M1 mirror. TMT control system can move segments individually and the guide flexures allow the segments to move while resisting lateral motions. This test is part of the performance assessment to ensure the control system can align the mirror to achieve the required telescope performance.
Akamai interns from TMT and UC Santa Cruz surrounded by their mentors at TMT project office in Pasadena for the 2018 internship symposium on Tuesday 14 August, 2018.
Representatives from TMT’s MICHI team, including Professor Chris Packham (UTSA & NAOJ), Mitsuhiko Honda (Kurume University, Japan), Professor Gregory Herczeg (PKU, China), Professor Lei Hao (SHAO, China), representatives of TMT-China office and Chinese Astronomers and engineers