Calypso Spectrograph

The goal is to build a spectrograph for the Calypso Telescope in Kitt Peak, Arizona. This spectrograph will replace the high definition camera currently connected to the Calypso Telescope and will equip it with spectrographic capabilities with the long-term goal of achieving better than 1% photometry through calibration.

Structural and Optical Design

Samuel Gonzalez

The spectrograph and its optical components will be built on a 900x900x59 mm metric breadboard. The breadboard provides vibration dampening and stiffness with its ferritic stainless steel skins. The breadboard is to be attached perpendicularly and horizontally to the Calypso telescope’s rotating mounting ring. The breadboard and its optical components must rotate 360 degrees freely along the axis of the mounting ring. The breadboard must be mounted at a distance of 10 cm below the focal point of the Calypso Telescope. The Breadboard has a mass of 62 kg and the optical components will have a mass of approximately 45 kg. In order to mount the breadboard, I am to design a structure given constraints of strength, weather conditions and space. My initial proposed solution consists of a light, high strength structure made from aluminum profiles and zinc hinges from item® corporation. Profiles from item® corporation are low cost, high strength and practical for use. Front, side and bottom views of the proposed solutions are displayed below. My current task is to determine the behavior of the aluminum amid the steel skins of the breadboard due to thermal expansions. I am considering the effect of the difference in coefficients of thermal expansion of the aluminum and steel on the breadboard and on the overall structure. Results from thermal as well as structural analyses will confirm if aluminum is the appropriate material. Large amounts of deflection may call for change of the material used for the structure and/or may call for change in the design of the structure. After finalizing the structural design, I will team up with Steven Villanueva to continue the design of the optical layout.