Modular Thermal Design Concepts: Thermal Design of a Spacecraft on a Module Level for LEO Missions

The thermal design of a spacecraft is primarily dependent on its nominal operating environment, which is typically characterized by: 1) defined Beta Angle ranges, which are derived from the orbit inclination, 2) orbital position of the spacecraft relative to major environmental sources, 3) orientation of the spacecraft relative to the environmental coordinate frame, and 4) a list of components with known duty cycles, power dissipations, and temperature ranges. However, in designing the thermal system for a modular spacecraft, which can have a wide variety of missions with unknown a priori orbital parameters, one does not have the benefit of these known characteristics. Two goals of a modular spacecraft design are that it be capable of operating in virtually any orbit and environmental condition, and that it is able to accept any component as long as the component meets the electrical and mechanical interface requirements defined by the spacecraft design. Traditional spacecraft design approaches make it difficult to accommodate these two modular design goals. As a result, the thermal design for a modular spacecraft must be addressed in a different manner than that of a traditional spacecraft. This paper explores the advantages and disadvantages to a modular thermal design