Radiation danger in prolonged manned space flights

The author examines methods for prognosticating solar activity for several decades to determine optimum periods for prolonged space flight. The focus of the discussion is the presence of a change in magnetic polarity at the beginning of each 11-year solar cycle, resulting in a 22-year cycle. An historical review of solar cycles determined a super cycle of about 180 years. Using this data, it is determined that solar activity will be weak through the end of the 20th century.     

Radiobiological risk and single event effects during manned space flights

Radiation hazard during previous manned space flights was not a critical problem as seen from monitoring on board MIR and the SHUTTLE. Future Martian and Lunar missions as well as flights on inclined or high altitude orbits around the Earth can be exposed to a large radiobiological risk and critical reliability losses can be expected, due to Single Event Effects on VLSI devices.

The mains characteristics of these hazards and some counter-measures to be provided for are given.     

Pathophysiology of motor functions in prolonged manned space flights.

The influence of weightlessness on different parts of the motor system have been studied in crew members of 140 and 175 days space flights. It has been shown that weightlessness affects all parts of the motor system including (i) the leg and trunk muscles, in which severe atonia, a decrease of strength and an increase of electromyographic cost of contraction have been observed, (ii) the proprioceptive elements and the spinal reflex mechanisms in which decreased thresholds accompanied by decreases of maximal amplitude of reflexes and disturbances in cross reflex mechanisms have been found. and (iii) the central mechanisms that control characteristics of postural and locomotor activities. The intensities and durations of disturbances of different parts of the motor system did not correlate to each other, but did correlate with prophylactic activity during space flight. The data suggest a different nature of disturbances caused by weightlessness in different parts of the motor system.     

Medical problems of manned space flights onboard orbital stations.

Medical aspects of crew safety and life support as well as biomedical investigations form part and parcel of the preparation and conduct of manned space programs. The list of biomedical problems related to these programs is very long. The present paper concentrates on some of them.     

Optimizing electrostatic radiation shielding for manned space vehicles

The shield has three concentric grids having a net charge of zero. The voltage across the outer pair is chosen to repel electrons; and that across the inner pair is chosen to repel nucleons. The negative grid is coated to absorb ultraviolet light to prevent photoemission, and secondary emission is minimized by a grid/thin foil combination. Voltage is maximized and mass minimized by setting the ratio of the negative to the inner positive electrode radii to ≥ 2. The outer grid pair forms a space truss with rigid geodesic grid, from which catenary tensile members are suspended. For docking there is passage directly through the sparse gridwork of larger structures, or through a charge shifting vestibule on smaller. While efficiency increases indefinitely with size, favorable sizes for given voltages are indicated. Large modular habitats and small powered transport vehicles are protected with efficiencies several orders of magnitude over mass shielding against charged particle cosmic radiation.     

载人航天器系统重量控制方法研究

系统的重量设计和控制贯穿于载人航天器研制的全过程,在型号研制中占有非常重要的地位。文章结合载人航天器型号研制实践,描述了载人航天器系统重量构成、重量控制流程、不同研制阶段的重量控制要点、系统重量控制体会以及轻量化设计措施,为未来载人航天器型号设计和减重研究提供借鉴与参考。     

载人航天器手动控制系统设计

航天员手动控制系统可作为自动控制和地面处置的备份手段。为了提高航天员在载人航天器驻留期间应对设备故障和突发事件的处置能力,采用系统工程方法对航天员手动控制系统进行了设计。通过地面试验测试,证明该手动控制系统设计能够有效地降低设备故障以及突发事件给航天员安全带来的风险。     

载人航天测控通信系统

在原有卫星测控网的基础上规划设计的载人航天测控通信系统与国际标准接轨，通过国内外的地面测控站和遍布三大洋的四艘远洋测量船保证了地面与飞船的测量控制和通信，实现了多项关键技术突破。它不仅能满足载人航天任务的高可靠、高精度、高覆盖、高速率的需要，还能同时为30颗以上卫星提供测控通信支持，这标志着我国自主发展的航天测控通信技术达到了世界先进水平。     

载人航天器舱内辐射剂量监测技术综述

文章介绍了美国、苏联/俄罗斯载人航天器舱内辐射剂量监测技术及部分监测结果,分析了我国“神舟3号”和“神舟4号”飞船返回舱内的辐射剂量探测技术及结果,并在此基础上就我国载人航天器的辐射剂量探测方法提出若干建议。     

载人航天器舱内辐射环境及剂量分析

构建载人航天器模型,利用Geant4软件计算了银河宇宙射线中的质子穿过载人航天器后在水模体中的总吸收剂量以及次级粒子吸收剂量,并且统计了不同种类的次级粒子在水模体中的总数量分布。计算结果表明,次级粒子引起的辐射剂量所占比例为50%,且二次电子总数量达到了10~7量级。     

Space radiation concerns for manned exploration.

Spaceflight exposes astronaut crews to natural ionizing radiation. To date, exposures in manned spaceflight have been well below the career limits recommended to NASA by the National Council of Radiation Protection and Measurements (NCRP). This will not be the case for long-duration exploratory class missions. Additionally. International Space Station (ISS) crews will receive higher doses than earlier flight crews. Uncertainties in our understanding of long-term bioeffects, as well as updated analyses of the Hiroshima. Nagasaki and Chernobyl tumorigenesis data, have prompted the NCRP to recommend further reductions by 30-50% for career dose limit guidelines. Intelligent spacecraft design and material selection can provide a shielding strategy capable of maintaining crew exposures within recommended guidelines. Current studies on newer radioprotectant compounds may find combinations of agents which further diminish the risk of radiation-induced bioeffects to the crew.     

Emergency and rescue considerations for manned space missions.

Man in space is totally dependent upon spacecraft systems. particularly those providing Environmental Control and Life Support (ECLS). It is therefore required that the design of manned spacecraft systems include provision for backup emergency and rescue modes of operation to insure adequate crew safety margin. This paper discusses safety, emergency and rescue provisions included in the Space Transportation System (STS), with emphasis on ECLS subsystems. Similar discussion is included for systems projected for use in future, extended duration manned space missions.     

Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights.

NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far. the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space. exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation methods--shielding and anti-carcinogens.     

空间辐射对空间站航天员的剂量影响分析

为有效实施对航天员的空间辐射防护,采用计算机断层扫描数据（CT）建立了精细化男性体素模型;基于Geant4建立蒙特卡罗程序计算空间站轨道辐射经过舱壁（5 g·cm^-2等效铝屏蔽）后在体模中的辐射剂量;分析了不同辐射粒子在体素模型组织或器官中的吸收剂量、当量剂量和有效剂量。计算结果表明：航天员体内吸收剂量大约80%来源于地球辐射带（ERB）质子;大约14%来源于银河宇宙线（GCR）质子;α粒子的剂量贡献占比约为5%;其余重离子的剂量贡献占比在1%左右。另外,航天员吸收的当量剂量和有效剂量50%左右来自于ERB质子,另50%左右来自于GCR粒子。计算结果将有助于评估航天员在空间站舱内的潜在辐射风险并提供辐射防护参考。     

关于航班大面积延误时的运行控制

近几年来,国内的航空公司航班数量、机队规模在不断增长,但航空公司面临的运行环境(包括恶劣天气、空中交通流量控制、飞机设备以及空中执勤人员执勤限制等等因素)却越来越复杂,当遇到航     

空间遥操作机器人系统控制参考模型

从分析智能系统中智能行为机制人手，研究了智能系统中自组织单元基本结构，基于智能工程中的集成单元结构，提出了遥操作机器人系统的递阶嵌套控制参考模型，并应用到遥操作空间机器人模拟实验中，完成了模拟舱内作业任务，验证了其实用性。     

载人航天器地面试验验证体系研究

在载人航天器的研制过程中,地面试验验证是保证产品在实际应用环境中正常运行、满足任务要求的主要手段之一。文章在对载人航天器试验技术与方法调研的基础上,系统总结了载人航天器试验覆盖性分析和验证的成功经验,提出了载人航天器系统级试验规划设计方法,找出了系统试验验证技术的薄弱环节。结合载人航天后续任务的特点,从试验管理、试验覆盖性分析、仿真与试验的协调、新型试验技术、试验基础设施等5个方面提出了载人航天器试验技术发展方向和需重点解决的问题,可为后续载人航天器的研制和试验技术发展提供支持。     

模拟载人探月中航天员空间辐射风险评估

空间辐射是长期载人航天飞行任务中影响航天员健康的重要风险因素。为了探求载人探月过程中对空间辐射的合理防护方式,文章借助空间辐射场模型对"嫦娥三号"飞行任务在不同质量厚度材料屏蔽下的舱内空间辐射环境进行了仿真计算,并确定了航天员各器官接受的空间辐射剂量、剂量当量以及有效剂量等辐射防护量以进行辐射风险评估。结果表明,随着屏蔽厚度的增加,航天员的各组织或器官的吸收剂量和剂量当量以及有效剂量均明显降低;采用质量屏蔽的方法对低于100 Me V的质子具有很好的防护效果,但对高能质子或重离子的防护效果不明显。计算和分析显示,载人探月过程中,只要采取适当的防护措施,航天员的空间辐射风险是可控的。     

载人航天器密封舱噪声控制与试验

载人航天器密封舱为航天员工作和生活的场所,需对航天员工作区和睡眠区进行噪声控制。文章以某中期驻留载人航天器为例,对其密封舱内的主要噪声源进行识别,并从吸声、隔声、消声、减振4个方面针对主要噪声源进行噪声控制。根据航天器实际噪声源和控制措施,构建了噪声计算模型,通过仿真分析获取了舱体内声压级水平分布,并对舱内噪声分布进行实际测试。仿真结果和测试结果表明噪声控制方案满足指标要求,噪声源识别准确,控制措施有效。     

Goals and preparation method for ground operations for the manned space flight Altair

The mission's success fully depends on the Payload Operations conducted during the space flight. The Ground Team has to be trained to assist the Space Crew, to replan the cosmonaut's activities when contingengies occurr onboard and to change or cancel Payload activities when required. In order to act efficiently during the mission, the Ground Team must be prepared in advance of the flight and able to operate special tools for tracking the mission's progress, anticipating problems and taking decisions in realtime.

This document sets out the approach for conducting such a preparation for Ground Operation. It will be focused on the Altaïr mission performed in July 1993 onboard the Russian Mir space station.