First, a status report is given for the on-going (Phase 2) instruments under construction now for Gemini. These instruments will be deployed during 2006 and 2007 at Gemini-South and collectively represent the end of an era of instrument building within the Gemini Partnership. Next, scientific applications and technical details for the next generation of "Aspen" instruments is described. These advanced future instruments will support breakthrough research in areas like extra-solar planets, dark matter, and dark energy. Gemini's ambitious adaptive optics development program in both current and future Aspen instruments is also described. Finally, a look back at some of the trials and tribulations of building instruments at Gemini is presented, with an eye toward the lessons of yesterday, how they helped mold today's program, and how they will likely impact the procurement of future instruments at Gemini.
Gemini's instrument program, which has existed for about a decade, has recently produced enough instruments to fully populate all of the instrument ports on both Gemini-N and Gemini-S. These delivered instruments, as well as those currently under construction and due to be delivered in the next ~2 years, are described in this report. We also summarize the bold new directions Gemini's development program will go in the next 5-10 years, as our Community embarks upon a new science mission to answer some of the most fundamental questions in astronomy.
We report in this paper on the design and progress of the ESO Laser Guide Star Facility. The project will create a user facility embedded in UT4, to produce in the Earth's Mesosphere Laser Guide Stars, which extend the sky coverage of Adaptive Optics systems on the VLT UT4 telescope. Embedded into the project are provisions for multiple LGS to cope with second generation MCAO instruments.
The design, manufacture and construction of the four 8 m VLT telescopes has been a major endeavor of the European Southern Observatory and European astronomy over the past twenty years. The final stages of this project, the assembly, integration and verification of the succession of four 8 m Unit Telescopes in the last three years, is the culmination of this great project. The successful achievement of this activity has been the result of a carefully planned campaign, using the best of telescope building methods developed on other projects over many years.
The 6.5 m upgrade of the multiple mirror telescope (MMT) will include a number of new secondary mirrors. For first light, there will be an f/9 Cassegrain secondary manufactured from a 1.0 m diameter Hextek borosilicate honeycomb meniscus blank. This f-ratio is designed to match that of the present MMT to allow the use of existing instrumentation for first light. This will be followed by the wide field f/5 secondary combined with a refractive corrector which includes an atmospheric dispersion corrector (ADC) to give a 1 degree unvignetted Cassegrain field. The f/5 mirror is made from a 1.7 m diameter lightweighted machined Zerodur blank. Two f/15 0.64 m diameter secondaries are being designed. The first of these is an adaptive secondary consisting of a thin 2 mm thick shell faceplate with 300 voice coil actuators and associated capacitive displacement sensors. A chopping f/15 secondary is planned using a rigid lightweight blank such as silicon carbide. The 8.4 m large binocular telescope (LBT) will have two secondaries for each of the two primaries. For first light, 0.87 m diameter f/15 Gregorian adaptive secondaries are planned. These concave mirrors will use the same thin shell faceplate, voice coil actuator and capacitive sensor technology currently being developed for the MMT f/15 adaptive secondary. A pair of 1.25 m diameter f/4 Cassegrain secondaries will be built next. These will be used together with refractive corrector optics to give a 1 degree field. These mirrors are being polished and tested at the Steward Observatory Mirror Laboratory (SOML) using the recently completed Secondary Fabrication and Test Facility. Stressed lap polishing is used to achieve the fast, highly aspheric surfaces and testing is done with the computer generated hologram (CGH) test plate technique. Each of these secondaries requires a support system, five axis actuation and thermal environmental control. The in-house development of this number of secondaries enables an integrated design approach. As much as possible of the development, design and hardware costs will be shared between secondaries. This paper describes the designs which are being developed for the support, actuation and thermal control for each of these secondaries.
The mirror-cells of the LBT (large binocular telescope) 8.4 m honeycomb borosilicate primary mirrors have to meet various requirements in addition to providing support to the mirrors and to the Gregorian instrumentation. The mirror-cells are directly connected to the main telescope structure and have a structural function themselves in order to supply a very high stiffness boundary to the position actuators (hardpoints) of the primary mirrors. The cells also must guarantee an overall strength to make up the bottom part of the vacuum shell, whose top part is the bell-jar for the mirror aluminizing. Each mirror cell has to hold several components inside: 160 pneumatic actuators for the active optics of the mirror, the thermal control system and its 252 air ejectors, and 6 position actuators. A further requirement for the mirror cell design is also to provide access for the maintenance of all the above sub-systems. In this report we summarize the main mirror-cells functions, their final design and briefly describe how we met all the specifications.
We present an overview of the new adaptive system under development for the conversion of the Multiple Mirror Telescope (MMT) to a 6.5 m continuous primary mirror. The system is optimized for diffraction-limited imaging from 1.6 to 2.2 micrometer wavelength, using an adaptive secondary mirror which directly feeds an infrared science detector at f/15 Cassegrain focus. Nearly full sky coverage will be obtained using a low-power, continuous wave (cw) sodium laser beacon to sense high-order wavefront errors, with image motion sensing using a quadrant detector sensitive to infrared field star photons in the 1.2 - 1.6 micrometer band. Components are currently under development, so that the adaptive instrument can be integrated with the new 6.5 m telescope soon after first light.
A new adaptive optics system has been constructed for moderately high resolution in the near infrared at the Multiple Mirror Telescope (MMT). The system, called FASTTRAC II, has been designed to combine the highest throughput with the lowest possible background emission by making the adaptive optical element be an existing and necessary part of the telescope, and by eliminating all warm surfaces between the telescope and the science camera's dewar. At present, only natural guide stars are supported, but by the end of 1995, we will add the capability to use a single sodium resonance beacon derived from a laser beam projected nearly coaxially with the telescope. In this paper, we present a description of FASTTRAC II, and show results from its first test run at the telescope in April 1995.
This paper will describe and discuss the methods which are being developed to support the large borosilicate honeycomb mirrors from the Steward Observatory Mirror Lab which are being used in the MMT 6.5 m conversion and the Large Binocular Telescope. The technique is similar to previous work carried out for the 3.5 m Phillips Lab mirror support.
The Anglo-Australian Telescope has just received a new prime- focus corrector, designed by Damien Jones (Prime Optics, Qld., Australia) and manufactured by Contraves, USA. The corrector is capable of producing aberration-corrected images over a full 2 degree diameter field of view. It is a 4-element design, the first two elements being rotatable cemented prismatic doublets approaching 1.0 m in diameter, which permit full atmospheric dispersion compensation to high zenith distances. The corrector is at the heart of a new powerful 400-fiber spectroscopic survey facility known as the 2dF. This A$2.3M project represents the largest investment in new technology and instrumentation the AAT has seen in its 20 year lifetime and will provide the telescope with a new and important role for large-scale statistical studies in the latter half of the decade and beyond. This paper will present the performance specifications for the corrector comparing them to the results of the recently complete telescope commissioning test.
The 2dF project aims at giving the AAT Prime-focus a 2-deg diameter corrected field of view geared primarily toward multiobject fiber spectroscopy. The combination of the 4-meter aperture of the AAT, a 400-fiber autopositioner and high throughput spectrographs should make the 2dF a powerful facility for statistical spectroscopic studies in the years to come. The design study for the corrector, fiber-positioner and spectrographs is now complete and the main conclusions are reported.
The evolution, current status, and planned improvements of the FLAIR fiber-optic-link multiobject spectroscopy system used on the 1.2-m UK Schmidt Telescope of the Anglo-Australian Observatory are reviewed and illustrated with diagrams and sample spectra. Consideration is given to the original FLAIR system using photographic film to record spectra, the introduction of a slow-scan cryogenic CCD camera in 1986, the problems of focal-surface coverage and sensitivity in the prototype FLAIR, the improved Panache fiber feed and on-chip pixel binning scheme installed in 1988, and the dispersion options offered by the FLAIR-Panache system. The limitations of the present FLAIR configuration are discussed, along with improvements involving (1) the use of a new spectrograph with Schmidt optics for both collimator and camera and (2) advanced plate-holder and positioner systems making it possible to load FLAIR into the telescope in a few seconds instead of an hour.
Results are reported from design studies of a fiber positioner and dedicated spectrographs for use in multiobject blue-UV spectroscopy at the new 2dF wide-field prime focus of the 3.9-m AAT. The technology of the present 64-fiber Autofib-1 system is being adapted to handle the 400 fibers and multiple spectrographs needed for the 2-deg unvignetted 2dF field; requirements include reconfiguration time 8 sec/fiber with iterative centroiding, position accuracy 0.2 arcsec (10 microns), button diameter 3 mm, and fiber probe freedom + or - 45 deg in theta and 75 percent diameter in R, with multiple crossovers. The spectrograph specifications include high throughput at 100-350 nm, spectral resolving power 5000 or less, efficient collimators, fast camera optics, and ability to resolve spatially all 400 fibers or subsets at different wavelengths and dispersions. Data from tests of fiber focal-ratio degradation are presented in graphs and discussed in detail.