Paper 13094-10
Prototyping activities during the development of the GMT mount
16 June 2024 • 14:30 - 14:50 Japan Standard Time | Room G403/404, North - 4F
Abstract
The Giant Magellan Telescope (GMT) will be a 25-meter optical telescope with a maximum weight of about 2300 t, located on Cerro Las Campanas in Chile. To fulfill the challenging pointing and tracking accuracy requirements, as well as the functionality requirements of the auxiliary subsystems, complex design solutions needed to be developed. To support and validate the design of those subsystems and to provide reliable data and parameter for performance analysis, a variety of prototyping tests have been performed during the design phase. The telescope support consists of a radial spring system that allows thermal decoupling to the concrete foundation, an earthquake damping system as well as frictionless hydrostatic bearings and a high-performance direct drives and control system. Highly accurate and precise mechanical components need to be consistent to gravity-caused structural deformations. This requires special supports to avoid structural overload. These unique supports, especially developed for the GMT have been prototyped. Self-induced vibrations are one of the most disturbing influences on such complex control systems as well as the adaptive optics of the telescope and need to be suppressed or at least reduced wherever possible. Tests have been performed to measure and optimize vibration sources like cable wraps and electronic cabinets. The covers of the primary mirrors with a diameter of more than eight meters were developed and tested in full scale to ensure proper function even in tilted position when the telescope rotates in elevation. Falling object tests have been made to demonstrate the protection of the mirrors. An inflatable wash seal around each mirror has been tested to ensure reliable functionality. The presentation will provide an overview on the subsystem development test activities and show test setups and results of main component tests supporting the subsystems design and analyses.
Presenter
Ulrich Weis
OHB Digital Connect GmbH (Germany)
Ulrich Weis graduated in mechanical engineering at the Technical University of Darmstadt, Germany in 1995. He started at MAN AG, later MT-Mechatronics and now OHB Digital Connect, in Mainz with the SOFIA project, an infrared telescope integrated in a Boing 747 aircraft. For many years he focused on the hydrostatic bearing, vibration isolation system and spherical drive. In other telescope projects such as the GREGOR solar telescope, ALMA array of radio telescopes and DKIST solar telescope he was responsible for the development and testing of mechanical assemblies. He is also experienced in upgrades (e.g. EFFELSBERG 100m radio-telescope sub-reflector) and refurbishments (e.g. VENTSPILS 32m radio-telescope). He joined the GMT project in 2017 and is responsible for system engineering and the hydrostatic bearing.