Numerical Simulation of Geomagnetic Trapping of Anomalous Cosmic Ray Ions

A method for simulating the propagation processes for ions of the anomalous component of cosmic rays in the Earth's magnetic field is described with allowance made for a step-by-step stripping of the ions in the residual atmosphere and their trapping by the geomagnetic field. Numerical results are presented for the geomagnetic trapping of high-energy singly charged oxygen ions penetrating into the stripping region from interplanetary space.     

Exploring the solar system galactic frontier in extreme ultraviolet

The solar system galactic frontier—the region where the expanding solar wind meets the surrounding galactic medium—remains poorly explored. The sheer size of the essentially asymmetric heliosphere calls for remote techniques to probe the properties of its global time-varying three-dimensional boundary. The Interstellar Boundary Explorer (IBEX) mission (launch in 2008) will image the region between the termination shock and the heliopause, the heliospheric sheath, in fluxes of energetic neutral atoms. Global imaging in extreme ultraviolet (EUV) will likely be the next logical step in remote exploration of the galactic frontier from 1 AU. Imaging in EUV will establish directional and spectral properties of (1) the glow of singly charged helium (He⁺) ions in the interstellar and solar wind plasmas; (2) emissions of hot plasma in the Local Bubble; and (3) characteristic emissions of the solar wind. Global imaging with ultrahigh sensitivity and ultrahigh spectral resolution will map the heliopause and reveal the three-dimensional flow pattern of the solar wind, including the flow over the Sun's poles. This article presents the emerging concept of the experiment and space mission for heliosphere global imaging in EUV.     

Changes of properties of the materials of spacecraft solar arrays under the action of atomic oxygen

A procedure is developed for physical and chemical modeling and investigation of the weight, geometrical, and thermo-optical characteristics of polymer paneling materials of solar arrays and of the electric power of solar cells under the prolonged action of supersonic fluxes of atomic oxygen in orbit. The behavior of changes in the material characteristics as a function of the integral fluence of atomic oxygen is found. It is established that the electric power of solar cells is virtually invariable within the errors of measurements under irradiation by atomic oxygen flux with a fluence of no higher than 5 · 10²¹ cm^?2.     

“嫦娥一号”卫星观测近月太阳风离子特征

"嫦娥一号"卫星的太阳风离子探测器(SWIDs)的科学目标是研究太阳风与月球的相互作用以及相应的近月空间等离子体环境。文章利用"嫦娥一号"卫星SWIDs探测器在2007年12月30日的观测数据对近月太阳风等离子体环境,包括向阳侧太阳风离子、"拾起"离子以及在月球尾迹边界处的太阳风离子的特征进行分析,得到以下主要观测结果:1)在慢速太阳风中观测到双峰结构,分别为太阳风中的氢离子和二价氦离子;2)在行星际磁场具有明显昏向(+By)分量期间,在月球向阳侧持续观测到有月表散射或反射后被拾起的太阳风离子;3)与入射的太阳风离子不同,这些拾起的太阳风离子具有明显的角度分布特征;4)在行星际磁场昏向(晨向)期间,太阳风中的氢离子在月球尾迹北半球的边界处呈现减速(加速)特征并进入尾迹;而并未发现氦离子进入尾迹的特征。"嫦娥一号"卫星的这些观测数据对于认识近月空间等离子体环境有着重要的意义。     

空间原子氧环境对太阳电池阵的影响分析

空间原子氧是危害低地球轨道（LEO）航天器在轨性能的最主要空间环境因素之一,其强氧化性能够对包括太阳电池阵在内的航天器外表面暴露材料和组件造成危害。文章分析了某载人航天器在轨原子氧环境、原子氧对不同结构太阳电池阵所用材料的影响以及对太阳电池阵组件电性能的影响,结果表明原子氧对材料的作用能够引起太阳电池阵基板强度降低、电连接可靠性下降及电缆线护套失效等风险,材料的损伤会导致太阳电池组件电性能的下降。鉴于以上结果,作者建议在今后LEO长寿命航天器太阳电池阵研制中,应对原子氧环境条件进行详细设计;同时开展组件级试验,以对电池阵原子氧防护设计的有效性进行验证。     

Concentration of ions in the topside ionosphere as measured onboard the <Emphasis Type="Italic">DEMETER</Emphasis> satellite: Morphology and dependence on solar and geomagnetic activity

Variations in concentration of ions H⁺, He⁺, and O⁺ are studied at a height of about 700 km using the data of continuous observations onboard the DEMETER satellite at the decline and in the minimum of solar activity from 2004 to 2008. Latitudinal distributions, seasonal behavior, and irregular variations in ion concentrations and their dependence on solar and geomagnetic activity are considered. Within this altitude range, for the first time an analysis is performed of the dataset of many-year continuous observations in both hemispheres from the equatorial to subauroral latitudes. This made it possible to describe the seasonal and irregular variations of the concentrations of main ion species with better time and spatial resolution than in the available empirical models. The dependence of concentrations of three types of ions on solar and geomagnetic activity is studied at time scales from several days to several years, and it is shown that the anti-phase change in concentrations of O⁺ and light ions known from publications is partly a result of mutual dependence of solar and geomagnetic activity and is observed only at time scales beginning from several months. At time scales from several days to several weeks, variations in the concentration of O⁺ and light ions are governed mainly by solar and geomagnetic activity, respectively.     

LEO原子氧剥蚀太阳电池阵Ag互连材料的试验研究

暴露在低地球轨道(LEO)上的太阳电池阵,会与大量具有极强氧化性的原子氧发生碰撞,导致太阳电池阵中对氧原子敏感的Ag互连材料受到剥蚀。文章依据原子氧剥蚀Ag材料的机理,选取了约400 km高度轨道上1年时间内原子氧的累积通量作为最高剂量,进行了原子氧剥蚀不同厚度Ag互连材料的地面模拟环境试验。试验表明:Ag在原子氧作用下在宏观上会经历"氧化—剥落"的循环剥蚀过程。根据反应方程简化推导了Ag互连片的剥蚀厚度公式,同时结合试验结果计算出了不同厚度Ag互连材料的厚度损失率。该研究成果可为LEO太阳电池阵原子氧防护设计提供技术支持。     

The effect of heavy ions on the spectrum of oscillations of the magnetosphere

Some issues concerning the influence of multi-ion composition of plasma on the spectrum of ultralow frequency (ULF) oscillations in the magnetosphere are analyzed. Main emphasis is made on the effects that are perceptible by analyzing the results of observations of ULF oscillations. The resonator confining ion cyclotron waves in the equatorial zone high above the Earth is considered, as well as the near-equatorial waveguide existing under the plasmasphere arch and canalizing magnetosonic waves in the azimuth direction. It is shown that the very existence of the ion-cyclotron resonator would be impossible, if only one species of ions were contained in plasma. It is emphasized that the problem of excitation of magnetosonic waves with harmonics of the gyrofrequency of O⁺ needs further investigation. The effect of heavy ions on the spectrum of Alfvén oscillations of the magnetosphere is considered. Some arguments are presented giving evidence that existence of alpha-particles in the solar wind leads to an asymmetry of the spectrum of magnetosonic oscillations in front of the Earth’s bow shock. Anomalously large asymmetry is expected at immersion of the Earth into the “plasmasphere” of the flare-associated stream of solar plasma. The general conclusion is made that even a small admixture of heavy ions can have a substantial effect on the spectrum of ULF oscillations.     

Role of the ionosphere for the atmospheric evolution of planets

We have synthesized current understanding, mainly observations, with regard to ion escape mechanisms to space from the ionosphere and exosphere of Titan and Earth-type planets, with the intent to provide an improved input for models of atmospheric evolution on early Earth and Earth-type planets and exoplanets. We focus on the role of the ionosphere and its non-linear response to solar parameters, all of which have been underestimated in current models of ancient atmospheric escape (4 billion years ago). Factors that have been overlooked include the following: (1) Much larger variation of O(+) outflow than H(+) outflow from the terrestrial ionosphere, depending on solar and geomagnetic activities (an important consideration when attempting to determine the oxidized state of the atmosphere of early Earth); (2) magnetization of the ionopause, which keeps ionospheric ions from escaping and controls many other escape processes; (3) extra ionization by, for example, the critical ionization velocity mechanism, which expands the ionosphere to greater altitudes than current models predict; and (4) the large escape of cold ions from the dense, expanded ionosphere of Titan. Here we offer, as a guideline for quantitative simulations, a qualitative diagnosis of increases or decreases of non-thermal escape related to the ionosphere for magnetized and unmagnetized planets in response to changes in solar parameters (i.e., solar EUV/FUV flux, solar wind dynamic pressure, and interplanetary magnetic field).     

太阳电池阵新型互连片微连接技术探讨

太阳电池阵由多个太阳电池单体串并联组成,焊接部位多,因此电池电路的互连成为其可靠性的制约因素。文章通过分析太阳电池阵新型互连片焊接影响因素,并进行焊接工艺试验验证,摸索出新型互连片的焊接参数,满足太阳电池焊接强度要求,为航天器的长寿命设计提供参考。     

低地球轨道原子氧?太阳远紫外协合效应地面试验条件探讨

低地球轨道航天器表面聚合物材料受中性大气原子氧和太阳远紫外辐照的同时作用,表现出不同于单一因素分别作用的协合效应。文章在总结现有地面试验设备参数和不足的基础上,分析原子氧注量、远紫外曝辐照度随在轨时间变化的计算方法和输入数据特性,并以正立方体卫星为例计算得到典型轨道不同太阳活动环境下迎风面和非迎风面的原子氧注量和远紫外曝辐照度,以及远紫外曝辐照度/原子氧注量之比（注量比）随在轨时间的变化后,提出将该注量比参数作为有关地面试验条件制定的依据之一,以提高航天器外露材料原子氧?远紫外协合效应地面试验模拟的有效性。     

Malfunction of satellite navigation systems GPS and GLONASS caused by powerful radio emission of the Sun during solar flares on December 6 and 13, 2006, and October 28, 2003

Poor quality of functioning of GPS during solar flares on December 6 and 13, 2006 is analyzed in this paper. These flares were accompanied by extremely high (unexampled) level of the solar radio emission flux. A comparison is made of these events with the solar flare on October 28, 2003. Statistically reliable experimental evidence is obtained that GPS positioning was partially paralyzed on the sunlit side of the Earth during the strongest bursts of solar radio emission. The obtained results give a serious ground to revise the role played by space weather factors in operation of modern satellite systems and to take these factors into account more carefully, when such systems are designed and exploited.     

Long-term variations of asymmetry of the solar magnetic field and geometry of the interplanetary magnetic field

A comparative analysis of variations of the mean solar magnetic field and the interplanetary magnetic field over all history of their measurements is performed. Asymmetry of the solar magnetic field and its manifestation in the heliosphere is investigated. Long-term variations of the solar magnetic field and the heliosphere, which manifest themselves in alternation of dominating magnetic polarities of different sign, are discovered. On the basis of the analysis of cumulative sums of the IMF components, long-term variations of the IMF geometry and of the solar wind spiral angle are found. The cumulative sum of the IMF B _z component perpendicular to the ecliptic plane also shows long-term variations. Time intervals are revealed, in which negative values of the IMF B _z component dominate, and an increased geomagnetic activity is observed.     

Bursts of geomagnetic pulsations in the frequency range 0.2-5 Hz excited by large changes of the solar wind pressure

We present the results of studying the magnetospheres’s response to sharp changes of the solar wind flow (pressure) based on observations of variations of the ions flux of the solar wind onboard the Inreball-1 satellite and of geomagnetic pulsations (the data of two mid-latitude observatories and one auroral observatory are used). It is demonstrated that, when changes of flow runs into the magnetosphere, in some cases short (duration ~ < 5 min) bursts of geomagnetic pulsations are excited in the frequency range Δf~ 0.2–5 Hz. The bursts of two types are observed: noise bursts without frequency changes and wide-band ones with changing frequency during the burst. A comparison is made of various properties of these bursts generated by pressure changes at constant velocity of the solar wind and by pressure changes on the fronts of interplanetary shock waves at different directions of the vertical component of the interplanetary magnetic field.     

电动帆轨迹优化及其性能分析

电动帆是一种新兴的无推进剂损耗的推进方式,利用太阳风的动能冲力飞行。电动帆由数百根长而细的金属链所组成,这些金属链通过空间飞行器自旋展开,太阳能电子枪向外喷射电子,使金属链始终保持在高度的正电位,这些带电的金属链会排斥太阳风质子,利用太阳风的动能冲力推动空间飞行器驶向目标方向。针对电动帆轨迹优化问题,提出采用Gauss伪谱法进行轨迹优化,克服了间接法对协态变量初值敏感的缺点。考虑在太阳风暴等原因造成特征加速度改变的情况,基于Gauss伪谱法实现电动帆在线轨迹重新规划,提高电动帆对太阳风不确定性的适应能力。最后以太阳系外探测任务为例,对电动帆和太阳帆的性能进行对比,仿真结果表明电动帆在星际远航任务中所用时间较短。     

Vertical structure of the magnetic field in active regions of the sun at coronal heights

High-altitude measurements and magnetic field distribution in active regions are always an important problem to verify existing models at heights from units to hundreds of Mm. Optical methods of analysis of the magnetic structure work well only at the photosphere level. At the same time, the progress of radio astronomy methods of analyzing the solar radio emission [1] and of the theory of solar plasma radiation [2] facilitates introduction of new methods for measuring the magnetic field strength at various altitudes in the solar atmosphere. In this paper we use multi-wave observations of polarization of the radio emission of active regions in the microwave range together with precise magnetosphere data in order to develop a method of projection for measuring the height distribution of the magnetic field.     

红蓝光敏探测器空间环境效应探测数据分析

红蓝光敏太阳电池空间环境效应探测器利用镓铟磷和三结砷化镓太阳电池来探测空间污染、原子氧和辐射环境及效应,搭载在中国空间技术研究院自主研制的“新技术验证一号”卫星上。文章通过分析红蓝光敏探测器在轨1年时间的探测数据,得到如下结论：红蓝光敏探测器污染电池板功率下降2.7%,等效污染累积增加量2.23×10^-5 g/cm^2,日均6×10^-8 g/cm^2;原子氧探测器在轨道高度499.226 km运行11个月,原子氧积分通量探测数据为9.7×10^20 AO/cm^2;辐射效应探测器（三结砷化镓太阳电池）在轨1年后累计接受辐射剂量（等效1 MeV电子注量）5.49×10^11 e/cm^2。     

Ultraviolet studies of the interplanetary and local interstellar medium

A review of the last results of UV observations in the interplanetary space of neutral hydrogen and neutral helium in resonance lines HI λ1215.7 Å and HeI λ584 Å is presented. The history of discovery of the interstellar wind effect is expounded in the review, and interaction of the solar wind with the interstellar medium is briefly described. Models of the inner-heliospheric distribution of emissivity in the lines HI λ1215.7 Å and HeI λ584 Å are discussed, and possibilities of getting the solar wind parameters from UV observations in the L _α line are considered. Currently accepted parameters of the local interstellar medium are presented. The parameters obtained are compared with those derived from non-optical measurements.     

Interaction of Phobos with the Solar Wind Plasma

The interaction of Phobos with the solar wind is considered both theoretically and using the experimental data of the FGMM magnetometer that were obtained in the course of the Phobos-2mission. It is demonstrated that the ions serving as a source of excitation of magnetosonic waves can be accumulated around Phobos. Examination of the magnetometer data has shown that the observed effects of a local decrease of the magnetic field near the Phobos orbit correspond to magnetosonic waves. Observation of these effects depends on the geometry of an experiment.