The space environment consists of various complex phenomena, which could have a strong influence on the spacecraft operation in different aspects. Since the very beginning of space exploration, numerous studies have been done on the space environment. However, most of the existing literature focuses on the investigation of the details of environmental phenomena, while the space environment has rarely been discussed from the perspective of orbits types. Therefore, a comprehensive review on analyzing and comparing the environmental characteristics among diverse orbits in space is of great significance. In this paper, the main components of the space environment are introduced, including the neutral atmosphere, the plasma environment, the radiation environment, the macroscopic particle environment, the geomagnetic field, the temperature field, and the solar activities. The relations of the various space environmental components are also discussed. The dominant environmental components and their effects on spacecraft in different orbits, i.e., the geosynchronous orbit (GEO), the low earth orbit (LEO), the medium earth orbit (MEO), and the high earth orbit (HEO), are investigated, respectively. The space environment that should be taken into particular consideration is summed up to facilitate the design of the spacecraft in a specific orbit.

This article proposes a novel soft pneumatic actuator inspired by the segmented structure of earthworms. The actuator adopts a new structure of free bottom to eliminate the constraint of the bottom and enlarge the bending capacity of the actuator. Through simulation, it is found that the new actuator improves the bending angle by 20% and output force by 40% compared with traditional actuator. Moreover, key parameters of the actuator are analyzed to acquire their effect on bending angle and bending linearity. A guideline for the design and optimization of the actuator is proposed. To validate the simulation results, we build up a test platform to test bending angle and output force of the actuators, the results shows that errors between the simulation and the test remained in the limit of about 10%. Finally, a three-jaw soft gripper is fabricated and its grasping strategy is studied. The quantitative analysis shows its excellent adaptability and load capacity.

A new screw conveyor with flexible discrete spiral blades is proposed to solve the problem of particle material gathering between the screw and the tube wall in the traditional screw conveyor. With a theoretical analysis, the power consumption model of the screw conveyor with flexible discrete spiral blades is built. Then, its practicability is verified by simulation and experimental testing. The simulation results show that the increase of the spiral angle will raise the transportation speed of the particles. The diameter of the flexible blades raises with the increase of the power consumption of the screw conveyor. The experimental testing verified the analysis and simulation results.

Continuum robots, often taking inspiration from biomimetics, are an exciting novel research field and have great capability. New continuum robots can be inspired by biology such as seahorses, pipefish, and pipehorses which have both strong skeleton and great dexterity. The main idea contained in this paper is how to effectively employ the square components which aim to imitate the armor and to connect the square components with the ball pairs and soft surface. For displaying the dexterity features of the square continuum robot (SCR), both the bending and twisting capabilities were studied. Meanwhile, a comparison was also considered in order to validate and analyze the dexterity differences in numerical model, skeleton prototype and SCR. The static characters of SCR were shown both numerically and experimentally so that the mechanical properties are clear. Then, impact experiments were carried out to demonstrate the cushion effect. Additionally, the maximum grasping load was also determined to quantize the grasping capability. Finally, a robot system was developed to handle objects with various shapes. Our results reveal that SCR connected by the soft surface has improved flexibility, cushion stability, and bettergrasping capability, with some loss of dexterity compared to SCR’s skeleton.