考虑火箭约束的深空探测弹轨道拼接模型

针对深空探测任务轨迹规划中对于运载火箭弹道约束考虑不足、弹轨道拼接设计效率低的现状,建立了考虑运载火箭射向和末级滑行时间约束的弹轨道拼接计算模型,在无引力摄动假设下得到了任意深空出发速度条件下的运载火箭射向和末级滑行时间计算公式。利用该模型分析了弹轨道可成功拼接的集合范围随深空出发速度、发射场地理位置、火箭射向和滑行时间约束范围的变化规律。提出深空出发"赤纬-发射能量"(δ-C3)图方法,可在图上表示指定型号运载火箭深空发射能力可行域,结合深空轨道转移Pork-Chop图方法,可以快速判断该型运载火箭是否适用于特定深空发射任务。依据这一方法,提出了对我国未来深空探测运载火箭射向和末级滑行时间的能力需求。     

载人登月舱下降发动机技术研究

通过对国内外登月舱下降发动机的研究历史及最新进展的综合分析,提出了我国登月舱下降发动机初步方案:挤压式系统方案,重点考虑N₂O₄/MMH组合,也可以考虑LOX/煤油组合;泵压式系统方案,重点开展LOX/LCH₄膨胀循环变推力发动机技术研究。开展载人登月舱下降发动机的技术研究将对我国月球探测、火星探测等工程提供坚实的技术保障。     

Issues in planetary protection: policy, protocol and implementation

Planetary protection is NASA's term for the practice of protecting solar system bodies from Earth life while protecting Earth from life that may be brought back from other solar system bodies. Spacefaring nations will soon begin retrieving samples from Mars and other solar system bodies. For these samples, planetary protection is in order, and measures are already in place to prevent the forward contamination of Mars and other bodies by Earth microbes and the backward contamination of Earth by possible extraterrestrial life. A major goal of planetary protection controls on forward contamination is to preserve the planetary record of natural processes by preventing human-caused microbial introductions.     

Public opinion polls and perceptions of US human spaceflight

A belief exists in the United States about public support for NASA's human spaceflight activities. Many hold that NASA and the cause of the human exploration of space enjoyed outstanding public support and confidence in the 1960s during the era of Apollo and that public support waned in the post-Apollo era, only to sink to quite low depths in the decade of the 1990s. These beliefs are predicated on anecdotal evidence that should not be discounted, but empirical evidence gleaned from public opinion polling data suggests that some of these conceptions are totally incorrect and others are either incomplete or more nuanced than previously believed. This article explores the evolution of public support for space exploration since the 1960s. Using polling data from a variety of sources it presents trends over time and offers comments on the meaning of public perceptions for the evolution of space policy and the development of space exploration in the United States.     

Journey to the Moon: Recent results,science, future robotic and human exploration

The upcoming fleet of lunar missions, and the announcement of new lunar exploration initiatives, show an exciting “Journey to the Moon”, covering recent results, science, future robotic and human exploration. We review some of the questions, findings and perspectives given in the papers included in this issue of Advances in Space Research.     

人机交互风格及其发展趋势

人机交互的风格经历了命令界面、图形界面、多媒体界面等主要发展阶段，目前正向虚拟现实技术和多通道用户界面的方向发展。本文简要回顾人机交互技术的历史，并进而探讨什么是理想、自然的人机交互模式。     

基于修正Rife算法的脉冲回波相参积累算法

针对目标径向运动导致回波在波门内出现距离走动的情况,提出了一种针对径向匀速运动目标回波信号长时间相参积累的方法。该方法根据傅里叶变换的时移性质——不同时刻回波频谱相关序列的频率包含了各回波到达的时间延迟,通过修正Rife算法估计此时间延迟,最终确定并补偿各个回波的距离走动分量。仿真结果表明:提出的方法可以有效补偿各回波间的距离走动;信噪比低至-6dB时,算法的性能即可达到最优;补偿后积累信号的信噪比可以达到理想积累情况下的93%。     

Solar activity and human health at middle and low geomagnetic latitudes in Central America

The study of the possible effect of solar variability on living organisms is one of the most controversial issues of present day science. It has been firstly and mainly carried on high latitudes, while at middle and low latitudes this study is rare. In the present review we focused on the work developed at middle and low geomagnetic latitudes of America. At these geomagnetic latitudes the groups consistently dedicated to this issue are mainly two, one in Cuba and the other in Mexico.     

Four-month Moon and Mars crew water utilization study conducted at the Flashline Mars Arctic Research Station,Devon Island,Nunavut

A categorized water usage study was undertaken at the Flashline Mars Arctic Research Station on Devon Island, Nunavut in the High Canadian Arctic. This study was conducted as part of a long duration four-month Mars mission simulation during the summer of 2007. The study determined that the crew of seven averaged 82.07 L/day over the expedition (standard deviation 22.58 L/day). The study also incorporated a Mars Time Study phase which determined that an average of 12.12 L/sol of water was required for each crewmember. Drinking, food preparation, hand/face, oral, dish wash, clothes wash, shower, shaving, cleaning, engineering, science, plant growth and medical water were each individually monitored throughout the detailed study phases. It was determined that implementing the monitoring program itself resulted in an approximate water savings of 1.5 L/day per crewmember. The seven person crew averaged 202 distinct water draws a day (standard deviation 34) with high water use periods focusing around meal times. No statistically significant correlation was established between total water use and EVA or exercise duration. Study results suggest that current crew water utilization estimates for long duration planetary surface stays are more than two times greater than that required.     

Development of theoretical approaches to the control of a water-treatment system

The Advanced Life Support/NASA Specialized Center of Research and Training (ALS/NSCORT) focuses on research and development of technologies to support human habitation during space missions. This research was done as part of an effort to maintain crewmembers’ water supply in a closed life-support system. The water subsystem was the primary focus of this study because water is one of the most expensive and important resources for human survival.