This paper describes the design, status, and test program for the Giant Magellan Telescope (GMT) Primary Mirror Subsystem (M1). It consists of the mirror cells, positioning system, support systems, and thermal control system. The seven 8.4m mirror segments are excluded from this paper because they are considered a separate subsystem of the M1 System.
The M1 Subsystem leverages heritage design of similar telescope systems; for example, the Magellan telescopes and the Large Binocular Telescope. The M1 Subsystem incorporates pneumatic force actuators, hardpoints, and a thermal control ventilation system.
Design developments have been introduced to address the challenging levels of performance and unique requirements needed by the GMT telescope. Imaging goals necessitate an increase in mirror support performance, figure control, and higher-levels of thermal control. Additionally, there are challenges associated with matching and tracking the relative position of the seven mirror segments for mirror phasing. The design of the static support system needs to protect the mirrors from loads transmitted through the structure during an earthquake. Finally, the telescope design with interchangeable off-axis mirror cells necessitate mirror cells and support components that function under any range of gravitational vector orientations
. A full-scale Test Cell prototype is being constructed including production versions of mirror cell components to test and validate the M1 subsystem design. A Mirror Simulator will be used with the Test Cell to validate the M1 Control System. Later, a primary mirror segment will be used with the Test Cell to perform optical tests at the University of Arizona.
Observatories are important for the evolution of astronomical research. Equally important is their maintainability. Of
course, the management of our fixed budget as well as assuring reliability, availability and system efficiency is directly
related to the maintainability of this center of observation.
Can we manage this situation and maintain reliability, availability and efficiency? The answer is, yes. There are new
maintenance techniques that allow us to deal with these requirements.
PMO, Preventive Maintenance Optimization is one of the new techniques that has recently grown in popularity and it is
structured as follows:
- Prepare PMO
- Define System or Equipment according to Reliability Requirements
- Review Existing PM
- Screen Task for Removal
- Optimize Remaining Tasks
- Fill Gaps on PM
- Review Manufacture Recommendations
- Optimize PM Work Order
- Implement Change
- Evaluate Improvement.
The implementation of PMO is a process that will allow the Observatory to increase the efficiency of the Maintenance
plans. The results of this new process will not be evident immediately and will be evaluated in the future.
The Very Large Telescope (VLT) Observatory on Cerro Paranal (2635 m) in Northern Chile is approaching completion. After the four 8-m Unit Telescopes (UT) individually saw first light in the last years, two of them were combined for the first time on October 30, 2001 to form a stellar interferometer, the VLT Interferometer. The remaining two UTs will be integrated into the interferometric array later this year. In this article, we will describe the subsystems of the VLTI and the planning for the following years.