空气涡轮火箭发动机掺混燃烧研究进展

在混流燃烧室内组织富燃燃气与空气的高效稳定掺混燃烧对于空气涡轮火箭发动机（ATR）性能至关重要。回顾了国外各研究机构关于ATR掺混燃烧方案的试验研究,对波瓣混流器在航空领域强化内、外涵气流掺混中的典型应用及研究成果进行总结评述,总结并提出ATR掺混燃烧的特点和关键问题,分析了后续掺混燃烧研究中需重点关注的问题。     

一种用于微纳卫星的丙烷微推进系统

介绍了一种应用于某微纳卫星的丙烷微推进系统,该推进系统利用换热模块,在不额外消耗星上电能的情况下实现"液-气"的可靠转化,利用自身的稳压模块和控制模块,系统可实现50 mN推力的快速精确控制。通过轻量化设计技术,系统总重仅2.5 kg。     

NASA地球观测系统的数据和信息系统（EOSDIS）：处理,归档并分配大量地球…

地球观测系统数据及信息系统（ＥＯＳＤＩＳ）正在ＮＡＳＡ哥达德航天中心进行开发，目的是建立一个包含１５年数据的综合性全球数据库，数据量达几拍它（１拍它＝１０＾１５）。ＥＯＳＤＩＳ将指挥和控制一系列ＥＯＳ卫星，进行分布式数据处理，并在８个服务站进行数据归档和分配服务。本文介绍了ＥＯＳＤＩＳ的核心部件，主要是规划和处理科学数据产品的功能。     

航天器自主及其对传统测控网的影响

三十多年来,随着实用航天技术的发展,航天器的数目、种类以及复杂性不断增加。完全依赖地面的传统测控模式将无法负担由于航天任务的迅速增加而带来的巨大工作量。单从改造地面测控网入手还远不能彻底解决问题,只有发展航天器的自主能力才是根本出路。本文首先介绍了航天器自主的概念以及自主航天器的系统结构。对人们在导航、姿态、定点保持以及电源系统等领域所作的自主尝试进行了分析和总结。然后分析了航天器自主对传统测控模式可能产生的影响。初步得出测控网的中心任务将由测控保障转为以监视为主这一结论。同时指出,无论自主发展到怎样的高度,测控网仍是航天工程的一个必不可少的组成部分,仍然承担着大量的工作。     

Dual-frequency ultrasound for detecting and sizing bubbles

ISS construction and Mars exploration require extensive extravehicular activity (EVA), exposing crewmembers to increased decompression sickness risk. Improved bubble detection technologies could help increase EVA efficiency and safety. Creare Inc. has developed a bubble detection and sizing instrument using dual-frequency ultrasound. The device emits “pump” and “image” signals at two frequencies. The low-frequency pump signal causes an appropriately-sized bubble to resonate. When the image frequency hits a resonating bubble, mixing signals are returned at the sum and difference of the two frequencies. To test the feasibility of transcutaneous intravascular detection, intravascular bubbles in anesthetized swine were produced using agitated saline and decompression stress. Ultrasonic transducers on the chest provided the two frequencies. Mixing signals were detected transthoracically in the right atrium using both methods. A histogram of estimated bubble sizes could be constructed. Bubbles can be detected and sized transthoracically in the right atrium using dual-frequency ultrasound.     

Communicating bioastronautics research to students, families and the nation

The National Space Biomedical Research Institute (NSBRI) is supporting the National Aeronautics and Space Administration's (NASA) education mission through a comprehensive Education and Public Outreach Program (EPOP) that communicates the excitement and significance of space biology to schools, families, and lay audiences. The EPOP is comprised of eight academic institutions: Baylor College of Medicine, Massachusetts Institute of Technology, Morehouse School of Medicine, Mount Sinai School of Medicine, Texas A&M University, University of Texas Medical Branch Galveston, Rice University, and the University of Washington. This paper describes the programs and products created by the EPOP to promote space life science education in schools and among the general public. To date, these activities have reached thousands of teachers and students around the US and have been rated very highly.     

Lava cave microbial communities within mats and secondary mineral deposits: implications for life detection on other planets

Lava caves contain a wealth of yellow, white, pink, tan, and gold-colored microbial mats; but in addition to these clearly biological mats, there are many secondary mineral deposits that are nonbiological in appearance. Secondary mineral deposits examined include an amorphous copper-silicate deposit (Hawai'i) that is blue-green in color and contains reticulated and fuzzy filament morphologies. In the Azores, lava tubes contain iron-oxide formations, a soft ooze-like coating, and pink hexagons on basaltic glass, while gold-colored deposits are found in lava caves in New Mexico and Hawai'i. A combination of scanning electron microscopy (SEM) and molecular techniques was used to analyze these communities. Molecular analyses of the microbial mats and secondary mineral deposits revealed a community that contains 14 phyla of bacteria across three locations: the Azores, New Mexico, and Hawai'i. Similarities exist between bacterial phyla found in microbial mats and secondary minerals, but marked differences also occur, such as the lack of Actinobacteria in two-thirds of the secondary mineral deposits. The discovery that such deposits contain abundant life can help guide our detection of life on extraterrestrial bodies.     

吸气式发动机流道调节的影响

随着吸气式发动机技术的发展,大包线飞行已成为基本要求,需要发动机采用流道调节技术以满足大包线范围内的高性能要求。另一方面,采用流道调节技术无疑又会带来系统复杂度的提升和结构尺寸／质量的增加,对发动机乃至飞行器的综合性能产生影响。为了进行流道调节影响分析,本文对以冲压发动机为动力的巡航导弹按假想飞行条件和不同流道参数条件...