嫦娥三号探测器连续姿控的轨道动力学模型补偿及实现

针对嫦娥三号探测器的连续姿控喷气对飞行轨道产生的扰动影响,在精密定轨中建立了经验力补偿模型,并使用最小二乘估计算法计算经验力模型参数与探测器轨道。通过重叠弧段轨道精度评估法对该模型补偿效果进行了验证,结果显示,定轨预报的星历误差以及拟合残差均有所改善,特别是环月轨道的定轨精度由百米量级提高到十米量级。     

可展桁架天线在轨运行中温度场分析

利用热传导辐射理论,并引入天线所处的轨道条件。可计算可展桁架抛物面天线在轨运行时不同时刻的温度场.利用Fortran语言,编制了基于上述理论的有限元程序,可计算各种轨道条件下不同时刻天线的温度场.还可用于指导天线的热变形分析和热控制设计.     

基于目标特性的航天器太阳光压面积计算方法

太阳光压是影响深空探测航天器轨道确定与预报精度最主要的摄动力.针对实际任务需求,采用了一种基于目标特性的光压面积建模与计算方法,根据航天器形状、尺寸、表面材料以及材料光学特性等信息,实现了分析型光压模型的建立与求解,提高了计算效率和精度,可快速计算目标在光照方向上的光压面积、投影面积以及光压比例因子等参数.通过长方体光压面积理论值与仿真值的对比,验证了该方法的准确性和有效性.针对复杂结构探测器开展了光压面积计算,可为深空探测航天器精密定轨中的光压模型解算、定轨及预报提供参考.     

速率控制下的空间系绳的伸展

以地球同步轨道高度上的空间系绳的伸展为例,阐述了长度速率控制律中的参数对伸展过程的影响,控制律中参数选择的方法,最大系绳拉力的估算以及伸展过程中系绳应力的计算。     

应用双向时间传递的重力卫星时标误差自主测量

星间时标误差的自主测量对于中国自主研发地球重力卫星具有重要意义. 提出利用双向时间传递法实现重力卫星时标误差的自主测量, 设计了测量方案, 建立了包含卫星运动导致的链路非对称、电离层效应、设备零值以及随机测时误差在内的测量模型. 结合地球重力卫星相关特性, 分析了时标误差测量中各误差源的影响及相应的误差校正方法. 以GRACE重力卫星为例, 利用提出的方法和校正措施, 星间时标误差自主测量精度可以达到0.62ns, 其中误差主要来自系统零值标定误差和随机测时误差.     

The relationship between plasma effects and cosmic radiation studied with TriTel-LMP measurements during the ESEO mission

The main point of the paper is to use the simultaneous measurements of the energetic particle flux by TriTel and those of electron density by a Langmuir probe to study the question of to what extent solar electromagnetic and corpuscular radiation (galactic cosmic rays, particle precipitation from the radiation belts) are responsible for the ionization of the atmosphere. The electron density measured by the Langmuir probe is the sum of the ionization produced by the solar electromagnetic radiation and that due to the corpuscular radiation. The ionization produced by the solar electromagnetic radiation may be computed. The flux of energetic particles in an energy range may be determined by taking the difference between the threshold energy of the TriTel telescopes and the energy corresponding to the local cut-off rigidity. As the ESEO satellite will have a quasi-polar and circular orbit, the cut-off rigidity will change from low to high latitudes, thus enabling the assignment of different energy bands for the telescopes. Thus, it will be possible to determine which energy bands of particle produce ionization at different latitudes.     

Crew autonomy for deep space exploration: Lessons from the Antarctic Search for Meteorites

Future piloted missions to explore asteroids, Mars, and other targets beyond the Moon will experience strict limitations on communication between vehicles in space and control centers on Earth. These limitations will require crews to operate with greater autonomy than any past space mission has demonstrated. The Antarctic Search for Meteorites (ANSMET) project, which regularly sends small teams of researchers to remote parts of the southern continent, resembles a space mission in many ways but does not rely upon a control center. It provides a useful crew autonomy model for planners of future deep space exploration missions. In contrast to current space missions, ANSMET gives the crew the authority to adjust competing work priorities, task assignments, and daily schedules; allows the crew to be the primary monitor of mission progress; demands greater crew accountability for operational errors; requires the crew to make the most of limited communication bandwidth; adopts systems designed for simple operation and failure recovery; and grants the crew a leading role in the selection and stowage of their equipment.     

自由返回轨道的P平面参数快速设计方法

针对自由返回轨道求解过程中地心轨道类型变化造成的B平面参数方法计算失败问题,提出一种基于P平面参数的自由返回轨道快速设计方法。首先,基于轨道半通径参数的普适性,给出了不同轨道类型的P平面参数定义,建立了以P平面参数为求解目标量的自由返回轨道求解模型。其次,给出了基于P平面参数的自由返回轨道快速设计方法,在构建的瞬时地月惯性系下,以平面双二体自由返回轨道作为初值,实现了高精度力模型下的自由返回轨道快速求解。对8种构型自由返回轨道的设计结果表明,P平面参数具有类似于B平面参数的大收敛域,且有效解决了轨道类型变化对计算的影响,可直接应用于中国后续月球探测任务轨道设计。     

Human Mission from Planet Earth: finding a rationale for exploration of the Moon and Mars

This paper advances scenarios for an evolutionary approach to the establishment of a Human Mission from Planet Earth involving exploration and utilization of the Moon and Mars. Of critical importance are the concepts of robotic–human and Moon–Mars synergies. The paper discusses the rationale variables that have an influence on types of space activities pursued and thus the policy that leads to particular scenarios. In this regard, the technological, scientific, and sociopolitical/socioeconomic impacts and consequences related to a Human Mission from Planet Earth are examined.