Investigation of thermal management strategies for biological CubeSat payloads

To date, there is little to no publication on methods for thermal management in biological Cube Satellite (CubeSat) payloads. This study highlights the various strategies that may be employed for precise temperature control in CubeSat-based space experiments, particularly for biological payloads. It addresses the need for temperature management through an analysis of experimental findings. The objective is to cultivate Saccharomyces cerevisiae within the target range of approximately ± 5 C around 27 C for optimal growth. This research aims to develop a thermal management apparatus for yeast using a heater control circuit, with variations in pressure vessel (PV) design, attachment of Mylar films, and choice of heat spreader material and thickness. Specifically, this paper uses a thermal management apparatus that incorporates Mylar films as a passive thermal control method and Kapton film heaters as an active method. Additionally, the following three effective methods have been combined; double-walled PV structure with vacuum insulation, incorporation of 20 layers of Mylar film, and adoption of copper heat spreader with a thickness of 0.5T. The CubeSat falls within the 3U category, imposing power budget constraints up to 20 Watts. In a thermal cycling test (TCT) comprising three cycles, each lasting 30 min at −40 °C and 30 min at 50 C, the thermal management apparatus successfully maintained temperatures at 27 ± 5 C as targeted while consuming 6.14W of power, which is below the target power consumption of 20 W. In summary, this study provides insights into the selection of materials, components, and strategies necessary for achieving and maintaining temperature stability in a low Earth orbit environment, specifically for biological CubeSat payloads, a topic that has not been addressed. This paper thereby could help advance the field of space biology research.