Advances in Astronautics Science and Technology最新文献

High-resolution observation requires the design of space telescopes with larger and larger aperture. Larger but not heavier deployable sunshields are essentially needed. Due to the advantages such as smaller storage volume and lightweight, the membrane structure can meet the demanding requirements of the design of larger membrane sunshields and has gradually become a current research hotspot. This paper summarizes the research progresses of sunshield deployment technology from three categories: mechanically driven deployment, elastic deployment, and inflatable deployment. The folding methods of membrane sunshields with different geometric shapes are compared, and the research status of membrane folding technology is summarized. The summary gives some suggestions on future sunshield deployment and folding technology.

This paper introduces the lightweight thermal protection system (TPS) of The Chinese Mars probe Tianwen-1. The aerodynamic environmental conditions and important design elements are described and analyzed. The design idea, design scheme, analysis and experiment of the thermal protection system are mainly discussed.

Fengyun-3E(FY-3E) satellite is the first early morning orbit meteorological satellite for civil use in the world. It operates in the sun-synchronous orbit whose nominal altitude is 836 km and local time of descending node is 05:30–05:50. It is equipped with eleven payloads, which can realize comprehensive detection of various spectral bands from extreme ultraviolet, ultraviolet, visible, infrared to microwave. All-band absolute radiometric calibration in orbit has been realized on FY-3E satellite, with the calibration error of infrared band up to 0.4 K, microwave band up to 0.8 K, and visible near-infrared band up to 5%. FY-3E satellite can provide images, clouds and radiation, atmospheric parameters, sea and land surface, space weather and other products, which are important supporting data for weather forecast, climate monitoring and environmental disaster monitoring. This paper introduces the system design scheme of FY-3E satellite, summarizes the main technical features of the satellite, and looks forward to the application prospect of the satellite.

Chinese library classification number: V411.8; TP391.9

Document identification code: A

Due to the high specific strength and specific stiffness of the lattice structure, it has been widely used in aerospace and other fields. Aiming at the lightweight requirements of spacecraft, a research on the lightweight design of the pressurized structure is carried out based on lattice truss sandwich. An axisymmetric cell structure and arrangement method is proposed, which can improve the structural bearing efficiency under internal pressure load, reduce the structure weight and ensure the consistency of deformation. At the same time, the influence of the parameters of the lattice sandwich structure on the performance of the structure is analyzed by numerical simulation. The size effect of the pressured structure is analyzed, and the equivalent methods for different structures are evaluated. The calculation results of the equivalent model are verified, and the results are proved to be credible, which can greatly reduce the computational cost and time to meet the requirements of engineering applications.

Taking complex spacecraft shell structure containing local small features (such as support, assembly interface, stiffener, etc.) as the object. From the perspective of average, considering the leakage and disturbance of elastic wave propagation caused by local small features on the surface. Based on the fact that the energy path required for elastic wave propagation from one source to any other point on the structural shell is the smallest, a method of impact location using time history data is proposed. A simulation example of typical impact event location of pressure storage tank is given. The results show that the positioning error obtained by this method can meet the defined engineering requirements (0.5 m) for the disposal of impact events, and has a certain engineering reference value for the positioning of complex spacecraft structure cabin impacted by space debris.

This abstract proposes a design that helps analyze the causalities experienced by a spacecraft during communication loss or any unpredicted event. The idea is to build a mini backup box akin deployable spacecraft unit, also called a Redundant Unit that gets deployed under the command of the central unit on the occurrence of any possible danger to the spacecraft. This deployed unit ensures to picture and measure the spacecraft parameters at the time of deployment and store the data within it. This unit also serves the purpose of storing the backup payload data of a spacecraft under an uncompromisable fate. This helps in learning the potential dangers for a spacecraft alongside preventing the complete loss of mission data during any causality. This paper propounds the overall design of the structure and internal architecture of the Redundant unit with all the required subsystems, and technologies involved. The deploying mechanisms, payloads of the redundant unit, and methods employed will be presented on the basis of the most common possible fates for spacecraft.

In this paper, the spectral characteristics, performance of spaceborne radiation source, in orbit infrared radiometric calibration method and radiance data generation process of the Medium Resolution Spectral Imager (MERSI) of FY-3C satellite are introduced. The land surface temperature of typical areas is inversed using the radiometric calibration data. The nonlinear radiometric calibration method for the long wavelength infrared channel with wide spectrum is discussed, the cold space and on-board radiometer count values are obtained independently in each scanning cycle of the instrument, and the infrared channel in orbit calibration calculation is carried out. According to the infrared radiation calibration results, the single channel method is used to retrieve the land surface temperature. The calibration and inversion results provide an important basis for FY-3C/MERSI in orbit performance evaluation.

Ground tests of spacial mechanical products have the characteristics of few test subsamples and expensive test cost, which often appear the cases of zero-failure samples. The classic reliability evaluation methods cannot adapt to the reliability assessment needs of small subsamples and zero-failure samples for high-reliability, long-life spacial complex mechanical products. The characteristics of failure rate functions of typical mechanical products such as mechanical structure, motors, bearings, gears, valves, and so on have been analyzed. Then the reliability evaluation methods of spacial complex mechanical system have been deduced, which has been combined the prior data of Bayesian method. Bayesian posterior distribution function of exponential distribution has been established by the method, which makes use of uniform distribution as a prior distribution, and combines with the convex characteristics of exponential distribution’s failure rate. Bayesian posterior distribution function of exponential distribution has been utilized in products, such as motors, valves, etc., which have characteristics of presenting exponential distribution. The evaluation range of accumulative failure-rate has been reduced by making use of accumulative failure-rate and predicted failure rate of exponential distribution And the weighted least-squares method has been used in parametric fitting based on accumulative failure-rate Then high-precision estimated failure rate of exponential distribution has been obtained. In this paper, the calculation example of compressor filled with spacial propellant has verified the feasibility of the calculation method. The problems of the reliability tests’ few subsamples and evaluating efficiency for expensive, complex spacial mechanical products have been solved effectively by the above proposed method.

With the focus on docking and separation technology for on-orbit servicing, a novel docking mechanism designed for a modular satellite offers a highly effective approach for on-orbit satellite servicing and assembly. This paper introduces its principle and composition, the results of two kinds of tolerance mechanism and its simulation are given, and the conclusion that the two-valve tolerance mechanism is more suitable for allogeneic connection separation device is obtained. Finally, the prototype verification of the two-valve tolerance mechanism is introduced, and the conclusion to meet the requirements of the index is drawn.

With Kane dynamics theory, the multi-body dynamic models of deployable struts are established with considering the clearance root-joint and the deployable style and deployable process of the struts are studied. The dynamic performance of struts’ deployment is analyzed, such as geometric position, velocity, and acceleration, seeking the inherent regularity of each joint’s motion characteristics. The results show that root-joint’s clearance has almost no influence on the rotation angle and angular velocity of base strut, but to some extent effect on the angular acceleration of base strut. Amplitude of angular acceleration appears significant fluctuations in 0–2 s and stabilizes gradually, indicating the pin in the bush is in the state of constant contact and separation. The dynamic model of deployable struts considering root-joint’s clearance represents more realistically the dynamic characteristics of this system. The different hinges suffer different contact forces, and its impact how effects on the mechanism movement is different. Therefore, Analysis of the dynamic performance and design of deployable struts need to consider the impact of hinge clearance, which gain the motion characteristics of important parts during deploying process, providing guidance for future design of mechanisms and driving forces.