TMT’s Cleaning system for the Primary Mirror (M1) optics is automated and uses CO2 to clean the 492 mirror segments mounted in the M1 cell. Four robotic cleaning arms will sweep nozzles spraying CO2 evenly across the primary mirror. This cleaning process will be performed with the telescope locked in horizon-pointing orientation.
TMT’s fully-automated CO2 snow cleaning in-situ process will use four robotic arms carrying spray nozzles that will produce CO2 snow to drive any dust particle off the primary mirror surface. The cleaning system will move the arms across the surface of the mirror at a uniform distance and controlled speed.
TMT’s Primary Mirror surface will be regularly cleaned by four robotic arms. The arm devices will sweep across the mirror and spray snow carbon dioxide through an arrangement of nozzles to remove dust and small particles. The CAD model of the arm supporting the CLN system is courtesy of MELCO.
The WFOS design now features a vertical orientation that enables the instrument to be gravity invariant as it de-rotates the field during observations.
The design is showing the Nasmyth platforms (in blue) and two of our early light instruments. The TMT Wide Field Optical Spectrometer (WFOS) is located on the right platform while the Adaptive Optics system (NFIRAOS) plus the InfraRed Imaging Spectrograph (IRIS) are located on the left platform.
A rendering of the Wide-Field Optical Spectrometer (WFOS) Instrument shown in-situ on the TMT Nasmyth Platform - WFOS is a wide field, seeing limited multi-object optical spectrometer and imager. Light from the TMT Tertiary Mirror (M3) is delivered to the WFOS Atmospheric Dispersion Corrector (ADC). The new instrument layout is optimized to be compact.
Excerpt from a Mechanical Interface Control Document showing where sonic anemometers (wind speed sensors) will be located on the telescope structure. The telescope-mounted sensors and sensor stations are identified in the Space Envelope drawings
Diagram of the CRYO space envelopes layout (in blue) on the Nasmyth platforms. CRYO will provide liquid nitrogen cooling to first-light instruments.
During installation of the TMT telescope, metrology frames will be used for initial alignment of TMT Primary Mirror segments.
First TMT M1 Metrology Frame Inspection The metrology frame, sitting on one TMT fixed frame, is being tested using advanced metrology system (pictured on the right) at TMT’s technical lab in Monrovia, April 2020.
The TMT Enclosure System is a dome structure housing the telescope. The three principal enclosure moving components are the rotating base, cap and shutter structures. Combined rotation of the rotating base and cap provides a range of required azimuth and zenith angles. The shutter is a rotating structure enabling opening and closing of the telescope aperture.