Gallery

Primary Mirror Rendering

The 492 primary mirror segments are arranged in a circle 30 meters (98 feet) across. The two Nasmyth platforms are each 30 meters long, and will hold up to 8 instruments at one time.

Enclosure Interior

A cross section through the enclosure showing the 20 ton dome crane and the secondary mirror service platform. Both are folded up during normal operations in order to move them out of the way of the telescope.

Enclosure Exterior

The 66-meter diameter ''Calotte'' style dome offers a full range of motion while providing maximum wind protection by virtue of the minimum opening size. In low-wind conditions, 98 vent doors can be opened to provide natural ventilation.

Lower Section of Enclosure Exterior

The lower section of the unusual ''Calotte'' style enclosure rotates about a vertical axis and the upper portion rotates about an inclined axis. The combination of these two motions allows the telescope to point anywhere within its intended observing range, from the zenith to 65 degrees away.

Telescope Servicing

Removal of the M3 and its and its mirror cell using the mobile crane, with the telescope pointing 45 degrees from the zenith.

Telescope Overview

The Thirty Meter Telescope will be 50 meters (164 feet) tall and 56 meters (184 feet) wide.

Service Cranes

Two cranes will be permanently mounted on the telescope to allow easy removal and replacement of mirror segments, to renew their reflective coatings.

Moving Mass

The moving mass of the telescope, optics and instruments will be 1430 metric tons.

Telescope Mount

TMT will be mounted on a cylindrical concrete pier. Both the azimuth and elevation bearings will be hydrostatic to provide smooth motion with very low friction.

Telescope Structure

The telescope structure is based on an Altitude-over-Azimuth (Alt-Az) mount design with Nasmyth platforms on either side for the science instruments.

Secondary Mirror (M2)

The Thirty Meter Telescope secondary mirror (M2) is shown in its support structure. The M2 mirror is 3.1 meters (10 feet) in diameter and is actively controlled to minimize the effects of gravity and temperature on its surface figure.

Tertiary Mirror (M3) Assembly

The Thirty Meter Telescope tertiary mirror (M3) assembly is shown mounted atop the tertiary tower. The M3 mirror is 3.6 meters (12 feet) long and 2.5 meters (8 feet) in width. The orientation of the M3 mirror is precisely controlled in rotation and tilt to direct the light beam into the scientific instruments mounted on the Nasmyth Platforms.

Primary Mirror (M1)

The Thirty Meter Telescope primary mirror (M1) viewed from the backside. The fine lattice structure that is seen between the thick blue structure is the mirror cell. The mirror cell provides support for the 492 Primary Segment Assemblies. The mirror cell, in turn, is supported by the elevation cradle assembly (shown in blue).

Nasmyth Platform

The tertiary mirror can rotate and tilt to steer the science beam to any one of the 8 science instruments that will be mounted on the telescope.

Secondary Mirror Configuration

The configuration for removal of the M2 and its mirror cell, with telescope horizon pointing and the enclosure-mounted service platform deployed.

Showing Scale

To provide a sense of scale, the Thirty Meter Telescope is depicted in front of the TMT Project Office. The telescope rises more than 50 meters (164 feet) off the ground and is greater than 56 meters (184 ft) in width not including the enclosure. TMT showing scale.

Enclosure with All Vents Open

The Thirty Meter Telescope shown in its enclosure with all vents open. The vents are designed to optimize the air flow over the primary mirror so as to reduce mirror seeing effects.

Segment Support

Each segment is supported on a 27-point ''whiffletree'' mount, with a central diaphragm for lateral support. Three extremely precise position actuators maintain the segment in phase with its neighbors to a small fraction of a wavelength of light.

Primary Segment Assembly

An illustration of a Primary Segment Assembly mounted in the telescope mirror cell and viewed from below. The fixed frame assembly (gold) can easily be seen. The three blue boxes that are mounted to each fixed frame assembly are the M1 Control System actuators. The position of each segment tip, tilt and piston is controlled by these actuators.

Instrument Layout

The Nasmyth platforms with entire envisioned instrument suite supporting the science cases; the early light instrument suite includes WFOS, NFIRAOS, IRIS and IRMS (at the eventual location of NIRES-B on the slide), as well as the APS.

Laser Guide Star System

The equipment at the top end of the telescope includes the secondary mirror and the Laser Guide Star Facility (LGSF). The laser beam is transmitted to the top of the telescope by the Beam Transfer Optics to an Asterism Generator that produces multiple laser guide stars, then the Laser Launch Telescope projects the guide stars to the sodium layer of the upper atmosphere.