航天器爪型对接机构对接过程动力学仿真分析

航天器对接机构是完成空间在轨对接任务的核心机构,要保证成功完成对接任务,必须清楚掌握其对接过程动力学作用机理与表现。文章针对爪型对接机构的对接过程开展动力学研究,建立了考虑对接过程中的接触、摩擦及碰撞等非线性因素的对接机构动力学模型,进行对接过程的全程动力学仿真模拟,详细分析了对接过程的影响因素与作用机理,并从能量角度分析了缓冲器的工作性能,可为爪型对接机构的设计、对接初始条件确定和控制策略的制定提供参考。     

飞行器在轨服务

定义了在轨服务（OOS）的概念。介绍了OOS可实现的在轨检查、组装、更换修理、补给,以及轨道转移等功能,讨论了可扩展公共卫星平台、精确测量系统与控制软件、先进对接机构、燃料传输系统、先进机械臂系统,自主运行与管理等关键技术。阐述了OOS发展的需求与驱动因素,以及对飞行器设计中通用化与标准化、理念调整,以及可靠性与技术分配重构等的影响。     

一种用于空间机械臂的 微重力模拟悬吊配重试验系统

空间机械臂工作在空间微重力环境中,广泛用于太空中的舱段对接、在轨维修等操作,因此需要在地面模拟微重力环境以满足空间机械臂研制试验要求。文章基于国内外模拟微重力环境领域技术现状,依据型号研制试验要求,提出了一种用于大型空间机械臂性能和可靠性验证的微重力环境模拟悬吊配重试验系统,并给出了悬挂机构子系统、二维随动子系统、恒拉力子系统、位姿测定子系统的设计思路和具体方案。     

一种模块化微小型卫星对接机构建模仿真

面向微小卫星在轨服务的连接分离技术的需求,针对一种模块化微小型卫星对接机构,分析其机构原理,推导了机构的运动方程,并利用MATLAB验证机构的运动学模型的正确性,结合仿真定量分析机构可能出现的干涉问题,给出了不干涉条件。为研制用于模块化微小型卫星的对接机构提供一种运动学建模和仿真分析的 思路 。     

面向航天器在轨加注的地面模拟技术

文章结合近年来航天器在轨加注的相关研究,着重对其地面模拟试验技术进行了探讨。首先对国外相关地面模拟技术进行了综述,其次对一种新型地面模拟系统进行了详细介绍。该系统由气浮平台、航天器模拟器、光学测量系统、地面控制系统、自主对接和流体加注机构等组成,不仅能演示航天器在轨加注任务的全过程,而且能完整演示自主对接与分离、流体传输与控制、导引测量与推进等在轨加注关键技术。     

仿生壁虎微纳米黏附阵列的空间应用

采用仿生壁虎微纳米黏附阵列作为在轨服务时的捕获载荷,可为在轨对接提供一种新型模式。文章介绍了在轨对接技术的研究现状,重点介绍了仿生壁虎微纳米黏附阵列的作用原理及研究动态,并分析了其空间应用领域,以及需要突破的关键技术。     

航天器微振动力学参数测量单元设计与验证

针对某新型气象卫星的在轨微振动测量需求,分析微振动对于卫星及其精密载荷的影响,提出一种具有可切换量程和较高故障容错能力的卫星微振动测量单元设计方案.通过地面试验数据与在轨数据的对比,证明该系统能够准确辨识整星及高精度载荷在不同工况下的微振动力学数据.该系统功能的成功实现为进一步优化星体结构、改善高精度载荷工作环境提拱了...     

类杆锥式对接机构捕获动力学分析与参数设计

针对面向在轨服务的小型航天器上使用的类杆椎式对接机构,给出了其参数设计及其 动力学分析方法。采用虚功率原理和赫兹模型建立了对接机构的整体接触碰撞动力学模型, 通过对不同初始条件下捕获阶段动力学仿真评价完成了缓冲阻尼参数的设计,实现了对接机 构的整体性能满足设计目标要求。     

对接机构动力学仿真

以神舟飞船的对接机构为研究对象,介绍了不同研制阶段仿真的任务规划,给出了研究中的对接机构仿真分析的捕获缓冲参数设计、数字样机、对接过程动力学仿真评估、试验验证与模型修正,以及对接动力学试验等。     

微泵驱动流体回路主动热控系统在轨测试试验研究

简要概述了"浦江一号"卫星流体回路系统的设计方案和地面测试试验情况,并在此基础上详细介绍了在轨开展的流体回路系统的开环和闭环控制测试,以及微泵A和微泵B的长寿命测试。在轨测试结果表明:微泵驱动流体回路系统各部组件满足空间环境使用要求;系统软、硬件在轨各项性能长期稳定良好;流体回路系统可以实现航天器热量的快速收集与传输,具有灵活的热管理能力。     

在轨服务飞行器自动寻的段的接近策略分析

在轨服务飞行器在自主式在轨服务系统中发挥重要作用,实现在轨服务飞行器与目标服务对象间的交会是在轨服务任务过程的必要阶段。为优化交会过程自动寻的段的接近策略,对基于Hill方程的双冲量机动策略进行了分析,讨论了在轨服务飞行器的初始轨道参数和机动时间选择对接近过程的影响。运用典型算例,得出两航天器的轨迹、速度和机动消耗在不同坐标系的变化规律,指出了算例中机动消耗随在轨服务飞行器初始参数变化的特点。     

碰撞试验系统中加速度传感器特性仿真研究

航天器对接机构缓冲能力的强弱直接决定了航天器所受冲击的大小,因此对缓冲机构的性能进行测试/试验具有重要的意义。文章以赫兹弹簧阻尼理论为依据,通过仿真计算,分析了质量、速度对碰撞过程的影响;得到了加速度的频率特性;确定了碰撞试验系统中加速度传感器的选择原则。     

星载辐射计动平衡概述及在轨动平衡技术研究

作为卫星在轨对地探测的有效载荷,星载辐射计在轨扫描转动时的动平衡特性直接影响卫星在轨探测精度和姿态稳定度。文章介绍星载辐射计动平衡技术研究现状和发展趋势,并基于现有地面动平衡技术的局限和型号发展需求提出在轨动平衡技术的初步设想,阐述了在轨动平衡配平技术、测量技术和实时调整反馈控制技术,可为今后类似旋转式星载辐射计的动平衡设计和动平衡控制方法提供参考依据。     

多任务在轨服务模块化智能航天器技术研究

首先介绍了在轨服务技术的分类及国内外近期研究进展,结合各国已开展项目的验证情况,分析了在轨服务模式、适应多任务在轨服务航天器的发展思路。为适应卫星发射和在轨服务的任务需要,提出了多任务服务航天器的方案设想,以期降低在轨服务操作的难度,提升在轨服务系统执行多任务的能力。最后初步分析了用于演示验证任务的服务航天器总体参数及任务规划。     

Design and on-orbit performance of the attitude determination and control system for the ZDPS-1A pico-satellite

The ZDPS-1A pico-satellite, developed by the Zhejiang University, is featured with a three-axis stabilizing capability. It is 15×15×15 cm³ cube-shaped satellite with a total mass of 3.5 kg. ZDPS-1A is the first pico-satellite that has been launched successfully in China. The mission of ZDPS-1A is on-orbit system verification of student-build pico-satellite and wide range earth observation with a micro panoramic camera. A miniature momentum wheel is employed to offer gyro stiffness stability in the pitch (orbit normal) axis. Magnetic coils are employed to generate control torques to achieve the three-axis stabilization of nadir-pointing. The attitude sensors employed in the design include two three-axis magnetometers (TAMs), a three-axis gyro, and two sun sensors. Both ground simulations and on-orbit testing are conducted to verify the feasibility of the given attitude determination and control system (ADCS).     

针对不同目标时对接机构适应性研究

讨论了对接过程的动力学模型、与不同质量飞行器对接过程的特点，以纵向性能为例，提出了缓冲性能参数与对接初始条件组合设计，使对接机构能够适应不同对接飞行器质量特性的要求。仿真结果表明，该方法是可行的。     

Severe disruption of the cytoskeleton and immunologically relevant surface molecules in a human macrophageal cell line in microgravity—Results of an in vitro experiment on board of the Shenzhou-8 space mission

During spaceflight the immune system is one of the most affected systems of the human body. During the SIMBOX (Science in Microgravity Box) mission on Shenzhou-8, we investigated microgravity-associated long-term alterations in macrophageal cells, the most important effector cells of the immune system. We analyzed the effect of long-term microgravity on the cytoskeleton and immunologically relevant surface molecules. Human U937 cells were differentiated into a macrophageal phenotype and exposed to microgravity or 1g on a reference centrifuge on-orbit for 5 days. After on-orbit fixation, the samples were analyzed with immunocytochemical staining and confocal microscopy after landing. The unmanned Shenzhou-8 spacecraft was launched on board a Long March 2F (CZ-2F) rocket from the Jiuquan Satellite Launch Center (JSLC) and landed after a 17-day-mission. We found a severely disturbed actin cytoskeleton, disorganized tubulin and distinctly reduced expression of CD18, CD36 and MHC-II after the 5 days in microgravity. The disturbed cytoskeleton, the loss of surface receptors for bacteria recognition, the activation of T lymphocytes, the loss of an important scavenger receptor and of antigen-presenting molecules could represent a dysfunctional macrophage phenotype. This phenotype in microgravity would be not capable of migrating or recognizing and attacking pathogens, and it would no longer activate the specific immune system, which could be investigated in functional assays. Obviously, the results have to be interpreted with caution as the model system has some limitations and due to numerous technical and biological restrictions (e.g. 23 °C and no CO₂ supply during in-flight incubation). All parameter were carefully pre-tested on ground. Therefore, the experiment could be adapted to the experimental conditions available on Shenzhou-8.     

空间对接缓冲试验台助推装置研究

设计了一种用于空间对接缓冲试验台的新型高动态响应助推力模拟装置。介绍了助推装置的机构组成和原理,计算了助推气动系统的响应时间,并分析了助推运动过程。研究表明：该助推装置的响应速度快、精度高,助推力方向实时通过模拟飞行器的质心,满足设计要求。     

在轨模块更换任务动力学与控制仿真系统

航天器在轨模块更换任务的总体仿真是对总体方案进行系统性分析和论证的重要手段。文章基于天基平台在轨模块更换技术的研究,搭建了在轨模块更换仿真演示验证系统,介绍了仿真系统总体架构,建立了包括空间环境、轨道、动力学、控制、电源、测控等各分系统在内的仿真系统。重点对交会对接、在轨模块更换过程涉及的航天器平台及机械臂的动力学特性...     

Short profile for the human spacecraft Soyuz-TMA rendezvous mission to the ISS

Reduction of flight duration after insertion till docking to the ISS is considered. In the beginning of the human flight era both the USSR and the USA used short mission profiles due to limited life support resources. A rendezvous during these missions was usually achieved in 1–5 revolutions. The short-term rendezvous were made possible by the coordinated launch profiles of both rendezvousing spacecraft, which provided specific relative position of the spacecraft or phase angle conditions. After the beginning of regular flights to the orbital stations these requirements became difficult to fulfill. That is why it was decided to transfer to 1- or 2-day rendezvous profile. The long stay of a crew in a limited habitation volume of the Soyuz-TMA spacecraft before docking to the ISS is one of the most strained parts of the flight and naturally cosmonauts wish to dock to the ISS as soon as possible. As a result of previous studies the short four-burn rendezvous mission profile with docking in a few orbits was developed. It is shown that the current capabilities of the Soyuz-FG launch vehicle and the Soyuz-TMA spacecraft are sufficient to provide for that. The first test of the short rendezvous mission during Progress cargo vehicle flight to the ISS is planned for 2012. Possible contingencies pertinent to this profile are described. In particular, in the majority of the emergency cases there is a possibility of an urgent transfer to the present 2-day rendezvous profile. Thus, the short mission will be very flexible and will not influence the ISS mission plan. Fuel consumption for the nominal and emergency cases is defined by statistical simulation of the rendezvous mission. The qualitative analysis of the short-term and current 2-day rendezvous missions is performed.