The Giant Magellan Telescope (GMT) is one of three planned ground-based optical/IR Extremely Large Telescopes (ELTs) that will provide a generational leap in ground-based Optical/IR capability. The GMT Mount is the structural, mechanical, hydraulic, and electronic system that provides the overall framework for mounting and alignment of optics and science instruments, supports payloads and utilities, and provides the three main axes of motion consisting of azimuth, elevation, and Gregorian Instrument Rotator (GIR) rotations. The GMTO Corp. completed in 2019 a multi-stage acquisition process that led to the selection of OHB Digital Connect (ODC, formerly MT-Mechatronics or MTM) and Ingersoll Machine Tools (IMT) to supply the final design, fabrication, and installation of the GMT Mount. The Final Design Review of the Mount subsystem was successfully passed in June 2023. The fabrication of the Mount is split into two phases comprising first the rotating azimuth base structure and secondly the elevation and optical support moving structures. The Mount will be assembled and tested at the IMT factory to the largest feasible assembly state where all three motion axes and critical systems will be functionally tested. The Mount will then be disassembled, shipped, and reassembled and tested at the GMT’s Las Campanas site in Chile. The first phase of fabrication has begun starting with the Azimuth Track Segments. Full factory functional testing of the Hydrostatic Bearing System (HBS), the electric Direct-Drive System, the Earthquake Damping System (EDS), and the Azimuth cable wrap will be completed during the first phase of fabrication. This paper will describe the final design configuration of the Mount, major subassemblies, fabrication and test phasing, fabrication highlights to-date, and an overview of the prototype testing that validated the final design parameters.
The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, echelle spectrometer that specializes in the discovery and characterization of exoplanets using Doppler spectroscopy. In designing KPF, the guiding principles were high throughput to promote survey speed and access to faint targets, and high stability to keep uncalibrated systematic Doppler measurement errors below 30 cm s−1. KPF achieves optical illumination stability with a tip-tilt injection system, octagonal cross-section optical fibers, a double scrambler, and active fiber agitation. The optical bench and optics with integral mounts are made of Zerodur to provide thermo-mechanical stability. The spectrometer includes a slicer to reformat the optical input, green and red channels (445–600 nm and 600–870 nm), and achieves a resolving power of ∼97,000. Additional subsystems include a separate, medium-resolution UV spectrometer (383–402 nm) to record the Ca II H & K lines, an exposure meter for real-time flux monitoring, a solar feed for sunlight injection, and a calibration system with a laser frequency comb and etalon for wavelength calibration. KPF was installed and commissioned at the W. M. Keck Observatory in late 2022 and early 2023 and is now in regular use for scientific observations. This paper presents an overview of the as-built KPF instrument and its subsystems, design considerations, and initial on-sky performance.
Since the start of science operations in 1993, the twin 10-meter W. M. Keck Observatory (WMKO) telescopes have continued to maximize their scientific impact and to produce transformative discoveries that keep the observing community on the frontiers of astronomical research. Upgraded capabilities and new instrumentation are provided though collaborative partnerships with Caltech, the University of California, and the University of Hawaii instrument development teams, as well as industry and other organizations. This paper summarizes the performance of recently commissioned infrastructure projects, technology upgrades, and new additions to the suite of observatory instrumentation. We also provide a status of projects currently in design or development phases and, since we keep our eye on the future, summarize projects in exploratory phases that originate from our 2022 strategic plan developed in collaboration with our science community to adapt and respond to evolving science needs.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.