Enabling Future Spacecraft Missions through Isothermal Bus Thermal Management

Abstract

The Isothermal Bus architecture is a novel idea focused on approaching a single thermal node S/C representation. In effect, heat is shared efficiently between cold and hot components and in combination with thermal control, spatial and temporal variations in temperature are minimized. The Isothermal Bus can enable higher capability systems along with providing schedule and cost savings. A nominal case study was provided that compared a traditional TCS to the Isothermal Bus concept with a 7:1 switching ratio. While the traditional TCS could accommodate 300 W of bus power, it would require survival heaters. However, the Isothermal Bus concept would enable a 167% increase in bus power while almost eliminating the need for survival heat. I. Nomenclature AI&T= Assembly, Integration, and Test ATT = Active Thermal Tile HTC = High Thermal Conductance ITEMS = Integrated Thermal Energy Management System LEO = Low Earth Orbit MLI = Multilayer Insulation PnP = Plug-and-play OLR = Outgoing Longwave Radiation S/C = Spacecraft SMARTS = Satellite Modular and Reconfigurable Thermal System TCP = Thermal Control Panel TCS = Thermal Control Subsystem VHT = Variable Heat Transfer II. Introduction PACE exploitation provides tremendous opportunities. Since 1957, spacecraft (S/C) have been developed to take advantage of this new high ground by providing communication, scientific observation, weather monitoring, navigation, remote sensing, surveillance, and data-relay services. 1 However, space presents extraordinary challenges. Consequently, S/C have become exceedingly complex and costly. Current S/C can take 1 Senior Engineer, AIAA Senior Member. 2 Senior Mechanical Engineer, Space Vehicles Directorate, AIAA Senior Member. 3 Mechanical Engineer, Space Vehicles Directorate, AIAA Member. S Downloaded by PURDUE UNIVERSITY on June 24, 2016 | http://arc.aiaa.org |