This study aims to determine the heat flux absorbed by satellite surfaces with the use of temperature data acquired from the satellite. This process is the first step in the development of an attitude determination method, which is currently being conducted by the authors. The principles of heat flux determination and its limitations are explained. A simple heat flux sensor is proposed in this study to address such limitations. With sufficient temperature data, an inverse solution of the energy equation can be used to determine the heat fluxes absorbed by heat flux sensors. The accuracy of the method depends on the resolution of the sensors used to acquire temperature data. The effects of temperature sensor resolution on the accuracy of the results are discussed in this paper.