Proceedings of the 4th International Forum on Heat Transfer, IFHT2016 November 2-4, 2016, Sendai, Japan IFHT2016-1912 *Corresponding Author: erdinc.mermer@tubitak.gov.tr 1 THERMAL MANAGEMENT OF PAYLOAD DATA PROCESSING AND STORAGE UNIT Erdinç Mermer, Barış Mıhçak, Altuğ Okan, İsa Kavas TÜBİTAK Space Technologies Research Institute, Ankara, Turkey ABSTRACT Many electronic equipment and subsystems were designed by TUBITAK UZAY and integrated to first in-house built RASAT and GOKTURK-2 satellites, which have been successfully working without anomaly since 2011 and 2012, respectively. Because of high performance requirements, the capacity and capability of satellites increase by time resulting in high power dissipation. Currently, TUBITAK UZAY is working on new Earth- observation satellite project which will accommodate electronic equipment smaller in size and higher in power dissipation. Payload Data Processing and Storage Unit (PDPSU) is one of such equipment under critical design phase, requiring high attention. In this study, thermal management of PDPSU was elaborated in details. Regarding the temperature requirements, PDPSU electronics were modelled using finite element method. Detailed thermal mathematical model was generated regarding both conductive and radiation parameters. Steady-state and transient analyses were conducted under worst case conditions regarding both the satellite platform and the operational condition of the unit. Sensitivity analysis was applied to the numerical model regarding several parameters such as mesh density, thermal conductivity, contact resistance and emissivity in order to satisfy requirements and keep the design robust. The design of the PDPSU will be verified by TVAC tests after numerical verification as a future work. KEY WORDS: Satellite Thermal Management, Electronics Cooling, Thermal Analysis, Computational Heat Transfer 1. INTRODUCTION TUBITAK Space Technologies Research Institute (TUBITAK UZAY) is the center of space and satellite technologies in Turkey, covering a wide envelope from spacecraft design to operations [1]. The institute developed first in-house payloads GEZGiN (Real-time Image Processing Unit) and COBAN (Multi-Band Camera) for BiLSAT, which operated successfully for 3 years in orbit between 2003 and 2006 [2]. First Turkish Earth- observation satellite RASAT, developed by TUBITAK UZAY, was launched on 17 August 2011 and still in operation controlled by TUBITAK UZAY’s ground station without any anomaly [3, 4]. The institute developed a high-resolution Earth observation satellite GOKTURK-2 between 2007 and 2012 with a local partner. The satellite was launched on 18 December 2012, and still in operation without any anomaly. The institute is currently leading a consortium developing the first national communication satellite project TURKSAT 6A and developing critical equipment on Earth observation missions. PDPSU is employed as a critical equipment in imager electronic box under the high resolution optical imager payload, currently being designed by TUBITAK UZAY. The equipment shows similarity on high power consumption and mission in Low-Earth orbit when compared with RASAT’s X-Band transmitter payload [5]. Concurrent design of PDPSU is in progress such that the iterative design is elaborated regarding the thermal, structural and electrical aspects. The imager electronic box is planned to house two PDPSU with a power unit and controller units as shown in Fig. 1 (a) and the PDPSU to be analyzed is shown in Fig. 1 (b).