<title>Teal Ruby-Design, Manufacture And Test</title>

Abstract

The Teal Ruby Experiment is an infrared telescope designed to passively operate in a cryogenic and orbital environment. As such, it had to be shown capable of maintaining integrity under a severe set of design criteria. Spacecraft payload capabilities required minimum optical element and structure weight while sufficient support strength was required to resist stresses developed under severe launch loading. Good stiffness characteristics were necessary to preclude excessive dynamic excursions as well as to minimize optical element motions caused by gravity release. Heat loss through supports which connect assemblies at different temperatures had to be kept to an extremely low value to assure life expectancy of the operational mission. Finally, low thermal expansion characteristics were a must if subassembly relative motions and cryogenic mirror distortions were to be held to the optical tolerances required. The recently completed telescope design satisfies these criteria and is presented in the paragraphs below. Here, a woven graphite epoxy composite structure houses lightweight fused silica mirrors. Variations in the coefficient of thermal expansion within the optical elements and structures are duly considered. The structural design and analysis, optical resolution capability, fabrication and manufacturing processes, and optical test results are discussed in detail.