“宇宙神”5发射MUOS-2卫星

7月19日,联合发射联盟公司的"宇宙神"5-551型火箭在卡纳维拉尔角空军站发射了美国海军的"移动用户目标系统"(MUOS)2移动通信卫星。卫星将经6个月在轨测试后宣布投入使用。MUOS-2是美海军MUOS新一代移动通信卫星系统的第二颗卫星,发射质量超过6800千克,是"宇宙神"5火箭迄今发射的最重的卫星。星上配备一个特高频窄带有效载荷,用于向海上舰     

太空新航线

<正>"宇宙神"5发射MUOS-3卫星1月20日,联合发射联盟公司的"宇宙神"5-551型火箭在卡纳维拉尔角空军站发射了美国海军的"移动用户目标系统"3移动通信卫星。该星是美海军新一代移动通信卫星系统(MUOS)的第三颗卫星,发射质量约6800千克。星上配备一个特高频窄带有效载荷,用于向海上舰船和信号难以到达地区的地面机动部队提供通信,并配备一个宽带有效载荷,用于提供手机式通信。耗资数十亿美元的MUOS系统最终将由4颗静地轨道卫星加一颗在轨备份卫星及4座地面     

不断升级的美国海军“传声筒”——首颗新一代窄带通信卫星进入轨道

2012年2月24日，美军首颗新一代窄带通信卫星——“移动用户目标系统”（MUOS）由“宇宙神”5火箭送入太空。它将用于替代美国海军现役的“特高频后继星”（UFO），提供窄带移动通信服务。据研制“移动用户目标系统”的洛马公司副总裁称：“新一代窄带移动军用通信卫星将极大地增强作战人员动中通的能力，包括得到增强的同步语音、视频和数据能力。”     

2012年的美国航天活动

2012年,美国航天活动精彩不断,不仅发射次数居世界第三,达13次,而且把"核区分光望远镜阵列"(NuSTAR)、辐射带风暴探测器-A、B(RBSP-A、B)等新型卫星送上太空,还发射了一些先进的军用卫星,如首颗新一代窄带通信卫星"移动用户目标系统"(MUOS-1)、第2颗"先进极高频"(AEHF-2)、第4颗"宽带全球卫星通信"(WGS-4)等军用通信卫星,第3颗全球定位系统-2F-3(GPS-2F-3)导航卫星,以及多颗美国国家侦察局的卫星。在2012年影响最大的美国航天活动有两个,一是2次发射"龙"     

美国第一颗配备GBS系统的军用通信卫星升空

美国第一颗配备ＧＢＳ系统的军用通信卫星升空□□１９９８年３月１６日,美国海军的第８颗“特高频后继星”（ＵｌｔｒａＨｉｇｈＦｒｅｑｕｅｎｃｙＦｏｌｏｗ－ｏｎ）由一枚宇宙神－２火箭从卡纳维拉尔角发射,进入地球同步轨道。这颗卫星简称ＵＦＯ－８,又称ＵＨＦＦ...     

空间扫描

日本三菱重工将为西班牙发射卫星 日本三菱重工业公司将使用H-2A火箭为西班牙卫星有限公司发射1颗卫星,这是日本火箭的首次商业发射。该通信卫星质量约为4t,发射日期在2005年底或2006年初。 美军移动用户目标系统正在招标 美军移动用户目标系统(MUOS)是一种能够改善运动中的美军武装力量地面通信能力的多卫星系统,是一种无防护的窄带卫星通信系统。MUOS系统设计的最后选定时间在2004年,初步作战能力预计在2008年实现,而实现完全作战能力则是在2013年。美国海军空间与作战系统司令部负责这个项目的管理。卫星通信在一体化战场空间中提…     

“德尔它”4发射WGS-6军事通信卫星

8月7日,联合发射联盟公司的"德尔它"4M+(5,4)型运载火箭在卡纳维拉尔角空军站发射了美国空军的"宽带全球卫星通信"(WGS)6军事通信卫星。WGS-6由波音空间与情报系统公司采用702HP平台建造,发射质量6500千克,是WGS系列2型卫星中的最后一颗,由澳大利亚国防军按2007     

MUOS-5卫星推进系统出现问题

正美国海军称,其"移动用户目标系统"(MUOS)5卫星用于提升轨道的推进系统6月29日发生故障,当时该卫星向地球同步轨道转移的工作刚进行了约一半。MUOS-5是美海军MUOS下一代窄带通信星座的第5颗卫星,6月24日由"宇宙神"5火箭在卡纳维拉尔角空军站发射,原定7月3日抵达夏威夷上空一个地球同步轨道测试位置。MUOS项目耗资77亿美元,主承包商是洛马公司。美海军正在考虑各种轨道调整选项,计算对任务的影响。该卫星目前处于稳定、安全和明确可控     

美国成功发射移动用户目标系统-4

2015年9月2日,美国成功发射移动用户目标系统-4(MUOS-4)卫星,这是美国在2015年发射的第2颗MUOS卫星。目前,这一5星星座已完成4星发射,构成了海军所谓的"初始星座",基本实现了全球覆盖。经过数月在轨测试之后,MUOS-4卫星将投入使用。配合地面站的建设和大系统联合测试,整个系统将于2017年实现"全面运行能力"(FOC)。届时,MUOS卫星的数字化载荷将为战术部队卫星通信能力带来质的飞跃。     

2016年国外导航卫星发展回顾

2016年,国外共进行8次导航卫星发射活动,成功8次.其中美国1次,成功发射了1颗全球定位系统-2F (GPS-2F);欧洲2次,成功发射了6颗"伽利略-全运行能力"(Galileo-FOC)卫星;俄罗斯2次,成功发射了2颗全球导航卫星系统-M(GLONASS-M);印度3次,成功发射了3颗"印度区域导航卫星系统"(IRNSS).截至2016年底,国外在轨运行导航卫星85颗,在轨运行并提供导航服务的卫星66颗,其中,美国GPS系统31颗,俄罗斯GLONASS系统23颗,欧洲"伽利略"(Galileo)系统11颗,日本"准天顶卫星"(QZS)1颗(主要提供GPS增强服务).     

2005年全球反恐特警队赛记

2005年3月30日到4月2日为期4天，在美国拉斯维加斯举行的全球特警挑战赛（Original World SWAT Challenge,OWSC）中，总计有18支队伍参赛。[编者按]     

Indirect search for Dark Matter with H.E.S.S.

Observations of the Galactic center region with the H.E.S.S. telescopes have established the existence of a steady, extended source of gamma-ray emission coinciding with the position of the super massive black hole Sgr A^*. This is a remarkable finding given the expected presence of dense self-annihilating Dark Matter in the Galactic center region. The self-annihilation process is giving rise to gamma-ray production through hadronization including the production of neutral pions which decay into gamma-rays but also through (loop-suppressed) annihilation into final states of almost mono-energetic photons. We study the observed gamma-ray signal (spectrum and shape) from the Galactic center in the context of Dark Matter annihilation and indicate the prospects for further indirect Dark Matter searches with H.E.S.S.     

The Comet Halley flyby I.R. sounder “I.K.S.”

An infrared sounder is being developed in France to observe in 1986 Comet Halley from the Soviet “VEGA” flyby probes. The instrument, called “I.K.S.”, has three measuring channels. Two of these channels will provide the spectrum of the comet emission in the spectral intervals 2.5–5.0 μ and 6–12 μ, at a constant resolution λ/Δλ = 50.The third channel analyzes the comet I.R. image at a spatial frequency of about 1 arc minute^?1; two I.R. colours are used in this channel: 7–10 μ and 10–14 μ. From the results expected, it is hoped that (1) most primary simple molecules emitted by the nucleus will be identified; (2) the chemical composition and perhaps crystalline structure of the dust grains and ices released by the comet will be derived; and (3) the diameter of the nucleus and its brightness temperatures will be measured.     

The C.E.B.A.S.-Minimodule: behaviour of an artificial aquatic ecological system during spaceflight.

The C.E.B.A.S.-Minimodule, a closed aquatic ecosystem integrated into a middeck locker and consisting of a Zoological (animal tanks), a Botanical (plant bioreactor), a Microbial (bacteria filter) and an Electronic Component (data acquisition/control system) was flown on the STS-89 spaceshuttle mission in January 1998 for 9 days. Preflight the plant bioreactor was loaded with 53 g of Ceratophyllum demersum (coontail) and the animal tanks with 4 adult pregnant females of the fish, Xiphophorus helleri (sword-tails), 200 juveniles of the same species less than 1 week of age, 38 large and 30 juvenile Biomphalaria glabrata water snails. The filter compartment was filled with 200 g of lava grain inoculated with laboratory strains of ammonia-oxidizing bacteria. A ground reference was undertaken with the same biological setup with a delay of 4 d. After an adaptation period of 5 d the system was closed and integrated into the spaceshuttle one day before launch. Video recordings of the animals were automatically taken for 10 minutes in 2-hour periods; the tapes were changed daily by the astronauts. The chemical and physical data for the aquatic system were within the expected range and were closely comparable in comparison to the ground reference. After 9 d under space conditions, the plant biomass increased to 117 g. The plants were all found in very good condition. All 4 adult female fish were retrieved in a good physiological condition. The juvenile fishes had a survival rate of about 33%. Almost 97% of the snails had survived and produced more than 250 neonates and 40 spawning packs. All samples were distributed according to a defined schedule and satisfied all scientific needs of the involved 12 principal investigators. This was the first successful spaceflight of an artificial aquatic ecosystem containing vertebrates, invertebrates, higher plants and microorganisms self-sustained by its inhabitants only. C.E.B.A.S. in a modified form and biological setup is a promising candidate for the early space station utilization as a first midterm experiment.     

Mechanisms underlying cellular radiosensitivity and R.B.E.: introductory remarks.

A general outline of the symposium titled "Mechanisms underlying cellular radiosensitivity and R.B.E." will be given in the introduction. The essential topics of molecular radiation biology are described with respect to the damage, repair and mutagenesis caused by high-LET irradiation to cellular DNA. The importance of clustered DNA lesions (locally multiply damaged sites) formed in vivo is discussed. This symposium is devoted to the mechanisms of the biological effects of radiation with high LET, especially with regard to the effects of heavy ions and neutrons which may cause possible risks in space flight, (e.g. carcinogenesis and mutagenesis). Detailed understanding of these risks, however, demands knowledge of the molecular mechanisms involved in the biological effects of high-LET radiations. Thus, it was the organizers' idea to hold a symposium dealing with primary physical and chemical events caused in cellular deoxyribonucleoproteins by densely-ionizing radiations and to relate them to track structures and energy transfer processes. The mechanisms of DNA damage were regarded from different points of view including those considering DNA repair and mutagenesis. Problems associated with cell survival and radiation protection were discussed as well. Our knowledge of the molecular mechanisms of high-LET radiation actions, however, is limited compared to what we know about low-LET radiation effects (e.g. from gamma-rays or X-rays). To emphasize this statement, I would like to summarize briefly the open questions in molecular radiation biology, what we know already about low-LET effects and what is lacking describing the effect of high-LET radiation.     

The "C.E.B.A.S. MINI-MODULE": a self-sustaining closed aquatic ecosystem for spaceflight experimentation.

The C.E.B.A.S. MINI-MODULE is the miniaturized space flight version of the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.). It fits into a large middeck locker tray and is scheduled to be flown in the STS 85 and in the NEUROLAB missions. Its volume is about 9 liters and it consists of two animal tanks, a plant cultivator, and a bacteria filter in a monolithic design. An external sensor unit is connected to a data acquisition/control unit. The system integrates its own biological life support. The CO2 exhaled by the consumers (fishes, snails, microorganisms) is assimilated by water plants (Ceratophyllum demersum) which provide them with oxygen. The products of biomass degradation and excretion (mainly ammonia ions) are converted by bacteria into nitrite and nitrate. The latter is taken up by the plants as a nitrogen source together with other ions like phosphate. The plants convert light energy into chemical energy and their illumination is regulated via the oxygen concentration in the water by the control unit. In ground laboratory tests the system exhibited biological stability up to three month. The buffer capacity of the biological filter system is high enough to eliminate the degradation products of about one half of the dead animal biomass as shown in a "crash test". A test series using the laboratory model of the flight hardware demonstrated the biological stability and technical reliability with mission-identical loading and test duration. A comprehensive biological research program is established for the C.E.B.A.S. MINI-MODULE in which five German and three U.S.-American universities as well as the Russian Academy of Sciences are involved.     

C.E.B.A.S. MINI MODULE: test results of an artificial (man-made) aquatic ecosystem.

The original Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) is a long-term multi-generation research facility for experiments with aquatic animals and plants in a space station the development of which is surrounded by a large international scientific program. In addition, a miniaturized laboratory prototype, the C.E.B.A.S. MINI MODULE, with a total volume of about 10-12 liters for a Spacelab middeck locker was developed and a first version was tested successfully for two weeks with a population of fishes (Xiphophorus helleri) in the animal tank and a Ceratophyllum spec. in the illuminated higher plant growth chamber. The water recycling system consisted of a bacteria filter and a mechanical filter and the silastic tubing gas exchanger was separated by valves for the utilization in emergency cases only. Data were collected with the acquisition module of the original C.E.B.A.S. process control system. In addition, an optimized version was tested for 7 weeks with fishes and plants and thereafter with fish and with plants only for 2 and 1 weeks, resp.. The paper presents the relevant water parameters (e.g., pH, pressure, temperature, oxygen saturation, flow rate, ion concentrations) during the test period as well as morphological and physiological data of the enclosed animals and plants. On the basis of the given results the possible role of the C.E.B.A.S. system as a scientific tool in artificial ecosystem research and for the development of a combined animal-plant intensive aquaculture system and its utilization in bioregenerative life support is discussed.     

Aquatic modules for bioregenerative life support systems: developmental aspects based on the space flight results of the C.E.B.A.S. MIN-MODULE.

The Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) is an artificial aquatic ecosystem which contains teleost fishes, water snails, ammonia oxidizing bacteria and edible non-gravitropic water plants. It serves as a model for aquatic food production modules which are not seriously affected by microgravity and other space conditions. Its space flight version, the so-called C.E.B.A.S. MINI-MODULE was already successfully tested in the STS-89 and STS-90 (NEUROLAB) missions. It will be flown a third time in space with the STS-107 mission in January 2003. All results obtained so far in space indicate that the basic concept of the system is more than suitable to drive forward its development. The C.E.B.A.S. MINI-MODULE is located within a middeck locker with limited space for additional components. These technical limitations allow only some modifications which lead to a maximum experiment time span of 120 days which is not long enough for scientifically essential multi-generation-experiments. The first necessary step is the development of "harvesting devices" for the different organisms. In the limited space of the plant bioreactor a high biomass production leads to self-shadowing effects which results in an uncontrolled degradation and increased oxygen consumption by microorganisms which will endanger the fishes and snails. It was shown already that the latter reproduce excellently in space and that the reproductive functions of the fish species are not affected. Although the parent-offspring-cannibalism of the ovoviviparous fish species (Xiphophorus helleri) serves as a regulating factor in population dynamics an uncontrolled snail reproduction will also induce an increased oxygen consumption per se and a high ammonia concentration in the water. If harvesting locks can be handled by astronauts in, e. g., 4-week intervals their construction is not very difficult and basic technical solutions are already developed. The second problem is the feeding of the animals. Although C.E.B.A.S.-based aquaculture modules are designed to be closed food loop systems (edible herbivorous fish species and edible water plants) which are already verified on Earth this will not be possible in space without devices in which the animals are fed from a food storage. This has to be done at least once daily which would waste too much crew time when done by astronauts. So, the development of a reliable automated food dispenser has highest priority. Also in this case basic technical solutions are already elaborated. The paper gives a comprehensive overview of the proposed further C.E.B.A.S.-based development of longer-term duration aquatic food production modules.     

V.L.A. observations of flare build-up in coronal loops

Very Large Array (V.L.A.) measurements at 20 cm wavelength map emission from coronal loops with second-of-arc angular resolution at time intervals as short as 3.3 seconds. The total intensity of the 20 cm emission describes the evolution and structure of the hot plasma that is detected by satellite X-ray observations of coronal loops. The circular polarization of the 20 cm emission describes the evolution, strength and structure of the coronal magnetic field. Preburst heating and magnetic changes that precede burst emission on time scales of between 1 and 30 minutes are discussed. Simultaneous 20 cm and soft X-ray observations indicate an electron temperature $\text{T}{}_{\mathrm{e}}\textcolor{red}{}\text{2.5 × 10}{}^7\text{K}$ and electron density $\text{N}{}_{\mathrm{e}}\textcolor{red}{}\text{10}{}^{10}\text{cm}{}^{\mathrm{?3}}$ during preburst heating in a coronal loop that was also associated with twisting of the entire loop in space. We also discuss the successive triggering of bursts from adjacent coronal loops; highly polarized emission from the legs of loops with large intensity changes over a 32 MHz change in observing frequency; and apparent motions of hot plasma within coronal loops at velocities V > 2,000 kilometerspersecond.     

Pigment composition and concentrations within the plant (Ceratophyllum demersum L.) component of the STS-89 C.E.B.A.S. Mini-Module spaceflight experiment.

The Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) Mini-Module, a Space Shuttle middeck locker payload which supports a variety of aquatic inhabitants (fish, snails, plants and bacteria) in an enclosed 8.6 L chamber, was tested for its biological stability in microgravity. The aquatic plant, Ceratophyllum demersum L., was critical for the vitality and functioning of this artificial mini-ecosystem. Its photosynthetic pigment concentrations were of interest due to their light harvesting and protective functions. "Post-flight" chlorophyll and carotenoid concentrations within Ceratophyllum apical segments were directly related to the quantities of light received in the experiments, with microgravity exposure (STS-89) failing to account for any significant deviation from ground control studies.