ESA及NASA测控通信网最新发展简介

本文简要介绍欧洲空间局(ESA)、美国国家航空航天局(NASA)测控通信网近期的变革及未来的发展。     

欧空局OPSNET通信网新进展

为了支持我国航天测控通信网的IP(互联网协议)化以及未来发展,对欧空局的航天任务操作通信网OPSNET(操作支持通信网)的新进展进行了研究。首先回顾了OPSNET网络发展历程中的里程碑事件(完成网络IP化,调整网络拓扑结构,通过载荷分担模式超越网络链路的带宽极限),之后介绍了该网络面临的高数据速率挑战及多个备选解决方案,详细介绍了最终选用的基于MPLS(多协议标签交换)技术的网络设计。OPSNET网络向MPLS迁移的方案经实验室环境验证后分步实施,经多个层面的验证及实际运行证明,采用MPLS技术后,以较低的成本实现了很好的网络性能。未来OPSNET将以此为基础部署更多的MPLS链路,并可能增加加密业务。OPSNET通信网的新进展值得我们关注和借鉴。     

NASA月球激光通信演示验证试验

为满足日益增长的大数据量、高数据速率传输要求,NASA(National Aeronautics and Space Administration,美国国家航空航天局)正开启采用激光技术进行空间通信的新时代,并于近年相继开展了多项自由空间激光通信技术研究项目。针对该情况,重点介绍LLCD(Lunar Laser Communications Demonstration,月球激光通信演示验证)项目的系统组成和工作状况:该项目由NASA实施,首次采用激光作为载波在绕月飞行器和地面接收机之间进行双向激光通信,通过飞行演示验证了下行速率为622 Mbit/s和上行速率为20 Mbit/s的月地双向空间激光通信,以及端到端DTN(Delay Tolerant Networking,容延迟网络)数据传输,并验证了作为激光通信链路副产品的高精度测距技术,试验成果超出预期。最后展望LLCD后续发展,供我国相关研究工作参考借鉴。     

Sunspot dynamics are reflected in human physiology and pathophysiology

Periodic episodes of increased sunspot activity (solar electromagnetic storms) occur with 10-11 and 5-6 year periodicities and may be associated with measurable biological events. We investigated whether this sunspot periodicity characterized the incidence of Pap smear-determined cervical epithelial histopathologies and human physiologic functions. From January 1983 through December 2003, monthly averages were obtained for solar flux and sunspot numbers; six infectious, premalignant and malignant changes in the cervical epithelium from 1,182,421 consecutive, serially independent, screening Pap smears (59°9″N, 4°29″E); and six human physiologic functions of a healthy man (oral temperature, pulse, systolic and diastolic blood pressure, respiration, and peak expiratory flow), which were measured ～5 times daily during ～34,500 self-measurement sessions (44°56″N, 93°8″W). After determining that sunspot numbers and solar flux, which were not annually rhythmic, occurred with a prominent 10-year and a less-prominent 5.75-year periodicity during this 21-year study span, each biological data set was analyzed with the same curve-fitting procedures. All six annually rhythmic Pap smear-detected infectious, premalignant and malignant cervical epithelial pathologies showed strong 10-year and weaker 5.75-year cycles, as did all six self-measured, annually rhythmic, physiologic functions. The phases (maxima) for the six histopathologic findings and five of six physiologic measurements were very near, or within, the first two quarters following the 10-year solar maxima. These findings add to the growing evidence that solar magnetic storm periodicities are mirrored by cyclic phase-locked rhythms of similar period length or lengths in human physiology and pathophysiology.     

2020年美国太空军事力量发展综述

1 出台系列战略政策 强化顶层统筹 美国出台太空领域系列战略政策文件,强化顶层战略统筹. 一是发布《国家航天政策》.2020年12月9日,美国白宫发布《国家航天政策》,阐述美国太空行动基本原则,再次阐明其"对美国及盟国太空系统任何蓄意干扰或攻击"都将予以反应的决心,明确美国民用、商业和国家安全航天的目标,以及在基础工作...     

低成本卫星地面控制设施的设计

该设计方法的核心是:卫星操作中的公共部分,即遥控、跟踪、子系统分析(包括遥测处理)、系统规划和调度、轨道确定和保持、数据传送和控制。特殊卫星任务的应用和操作另行考虑,以保证本设计方法可应用于许多种卫星系统。关于特殊卫星任务的讨论将限制在了解支持航天任务的地面控制设施总规模和业务范围。分离出“通用”卫星操作功能,可研究出一种低成本通用设计方法,该方法允许对系统作阶段性改进,而对在轨设施和测控性能影响极小。该方法的目标是提高卫星系统的可扩展性、可维护性和可操作性。     

Interaction between exercising humans and growing plants in a Closed Ecological Life Support System

The purpose of this study was to quantify the gas exchange between plants growing in a Closed Environmental Life Support System (CELSS) and the metabolism of human subjects undergoing various levels of physical exercise, and subsequently determine the buffer characteristics in relation to the carbon exchange established for plants in this closed loop life support system. Two men (ages 42 and 45 yr) exercised on a cycle ergometer at three different work intensities, each on a separate day. The CELSS, a 113 m³ chamber, was sized to meet the needs of one human. The plants, consisting of 20 m² of potato, provided oxygen to the human during an artificially lighted photosynthesis phase and the human provided CO₂ to the plants. The average rates of exchange for the subjects were 0.88, 1.69, and 2.47 liters O₂/min and 0.77, 1.47, and 2.21 liters CO₂/min at approximately 25%, 50%, and 75% of their maximal aerobic capacity, respectively. The photosynthetic rate for the CELSS was 0.95 liters/ min. A balance between human CO₂ production and plant utilization was noted at approximately the 50% VO_2max level. The oxygen balance and changes were not within detectable limits of the CELSS instrumentation for the durations of these exercise exposures. If a CELSS environment is the methodology selected for long term spaceflight, it will be important to select plants that efficiently grow at the available light and nutrient levels while balancing the needs for the human crew at their levels of physical activity.