No abstract

Launch missions of small satellites have been increasing in recent years. As the main payload, the camera plays a pivotal role in remote sensing detection. Therefore, on-orbit health estimation is a continuous concern for satellite design. This study aims to develop a dynamic intelligent health estimation algorithm for the on-orbit satellite camera. Based on fuzzy theory in the intelligent health estimation algorithm, the reliability and the remaining useful life are transformed into a newly defined health estimation index, namely “health vector,” which reflects camera health from the aspects of the electrical and mechanical parts. Compared with traditional methods, the new intelligent health estimation algorithm can not only judge the development direction of satellite camera’s health status, but also predict the degree of change. In addition, the proposed “health vector” is concise for engineers to monitor the health status of satellites in real time from the ground in multiple dimensions. In summary, this study provides a new method for on-orbit health management of satellite cameras.

Thermal performance has long been recognized as a critical attribute for space systems. Thermal control surface coating is a common method in passive thermal protection. Unfortunately, limited analyzing models and data on the influence of thermal control coatings’ α/ε (absorptivity/emissivity) on the space power system have been published to date. To fill this gap, we proposed a multiphysics model that combined environmental temperature calculating and electrical performance analysis together for the satellite power system. In this paper, different coating materials are applied to the radiator surface and thermal insulation surface, respectively. Additionally, a new concept of energy storage, named energy storage voltage, is introduced. The results are analyzed and parametric fits with different formulas using ordinary least squares are conducted. Finally, the change rules are presented, which will prove particularly useful to the space industry, for example, in thermal designs and on-orbit battery studies.

No abstract

The special use environment and uncertainty of extravehicular activities (EVAs) make it difficult to predict the lifetime consumption of extravehicular spacesuits in the traditional way. This paper presents a flexible reliability dynamic simulation model to predict the life loss of extravehicular spacesuits. Based on the images of traditional reliability change curves, new life assessment parameters, based on geometric analysis, are proposed as indicators of spacesuit life loss. Multiple influence factors are used to correct the spacesuit failure rate. The results of the study show that mission intensity is the main factor affecting the health status of the spacesuit, and the higher the mission intensity, the higher the failure rate. Additionally, the more frequently the spacesuit is used, the more times it is available, however, the overall service time will decrease. Concentrating on the mission at an early stage would lead to a significant and irreversible loss of life. Reliability is higher when more intense work is scheduled later in the EVA. Therefore, it is important to rationalize the mission duration, frequency, and work intensity of spacesuits. These reliability models predict the health status of the spacesuit and assist in optimizing the scheduling of EVA.