Thermal Influence of the Screw Axial Load on a 1-mm Accuracy Laser Ranged Satellite

Abstract

This work explores the role of the screw axial load on the temperature experienced by the mounting set of a Cube Corner Retroreflector (CCR) in a spherical satellite, designed to achieve 1-mm accuracy in satellite laser ranging. Since thermal gradients inside CCRs induce refractive index gradients, changing the optical behaviour, thermal analysis and simulation are needed to ensure the best performances. The screw axial load influences the thermal interface resistances between the rings of the mounting set, changing their thermal behaviour. It is important to study the temperature, not only for the thermal gradients inside a CCR, but also to check that the Kel-F mounting rings do not overcome their maximum operative temperature. Two models have been realized in the commercial software C&R Thermal Desktop®: a model to simulate the entire satellite behaviour and a detailed model to represent the cavity which includes the CCR and its mounting set. Different on-orbit scenarios are analyzed, focusing on the influence of the screw axial load in each of them.