ON-ORBIT TEMPERATURE DISTRIBUTION OF A SUBMILLIMETER-TELESCOPE PRIMARY-REFLECTOR PANEL

A preliminary detailed primary-mirror thermal analysis has been perfor med for the Earth-orbiting Submillimeter Imager and Line Survey Telesc ope. The purpose of the analysis was to determine the spatial temperat ure distribution in a panel that composes the primary mirror, The prim ary mirror is formed from seven separate panels, and minimization of t he temperature difference across the primary mirror is crucial to opti cal performance requirements. Previous work indicated that the tempera ture difference across the entire primary reflector mirror was small, but the nodal granularity was not sufficient to draw the same conclusi on for a single panel. A finite difference model with a Large number o f nodes for a particular panel was developed. Automated model generato r code was developed to facilitate model construction. Steady-state an alyses were performed, since the transitory effects of the Earth fluxe s are overwhelmed by the solar environment. The analysis indicates tha t the panel temperature distribution is extremely isothermal, and ther efore adequate optical performance is possible. A future, more rigorou s analysis now can be performed so that the figure error can be suffic iently quantified.