航天火工装置

文章分类介绍了几种航天火工装置的工作原理及应用情况,并根据航天科技对火工装置的性能及使用要求,进一步阐述了航天火工装置的发展趋势。     

航天火工装置

文章分类介绍了几种航天火工装置的工作原理及应用情况，并根据航天科技对火工装置的性能及使用要求，进一步阐述了航天火工装置的发展趋势。     

关于“航天火工装置及其发火元、器件”术语及其在标准中的表述

简介了火工装置、航天火工装置、发火元件和器件的概念,并就如何在标准中表述航天火工装置关键件及其与常规兵器火工品的差异作了分析和研究。     

火工装置在航天飞行器上应用

火工装置是航天技术的关键之一。文中介绍航天火工装置在航天飞行器上的应用实例。     

钝感火工装置的发展与应用

简述了钝感火工装置的一般概念、特点和分类,介绍了钝感火工装置在国外航天领域的应用简况以及我国钝感火工装置及钝感发火元器件的研制在航天型号上逐步推广应用的情况。     

航天火工装置无损检验方法标准简介

概述了航天火工装置无损检验对保证航天型号用火工装置的质量与可靠性、避免灾难性事故、提高发射成功率起的重要作用 ,分析了航天火工装置的中子照相、X射线和γ射线工业CT检验三项无损检验方法标准的共同技术要求 ,重点对这三项检验方法标准的适用范围及应用概况、检验系统仪器、设备配置和检验方法等技术内容作了介绍 ,并从型号研制需要出发 ,对尽快完善、配套航天火工装置无损检验标准 ,提出了建议     

冗余航天火工装置可靠性评估方法及应用

火工装置在航天领域有着广泛的应用,是航天关键产品,本身具有价格昂贵、高可靠性（多数要求达到0.9999以上）等特点。火工装置工作的成败,关系着人员的安危和任务的完成。产品在使用前,必须要通过试验来评估可靠性。因此对火工装置可靠性评估方法的研究有着重要的实际工程意义。针对冗余设计航天用火工装置,结合应力-强度等可靠性相关理论,采用强化试验思想提出了冗余设计航天火工装置的可靠性试验评估原理和可靠性试验验证方案。根据提出的原理及验证方案,首次通过试验评估并验证了冗余设计火工装置--某拔销器的功能可靠性,同时两种加严方式的试验也实现了相互验证,从而证明了提出的可靠性评估原理和试验验证方案的正确性及有效性,解决了小子样评估冗余类航天火工装置高可靠性的工程难题。     

用于连接与分离的非火工装置

文章主要介绍了几类航天上可用于连接与分离的非火工装置,如基于形状记忆合金(SMA)的连接释放装置,石蜡驱动器,低熔点材料释放装置。非火工装置具有冲击力小、无污染以及可重复使用等优点,非火工装置的这些优点正好是火工装置的不足之处,所以在不能使用火工装置的条件下可以考虑使用非火工装置。文章对接分离装置有一定的参考价值。     

用于连接与分离的非火工装置

文章主要介绍了几类航天上可用于连接与分离的非火工装置，如基于形状记忆合金（SMA）的连接释放装置，石蜡驱动器，低熔点材料释放装置。非火工装置具有冲击力小、无污染以及可重复使用等优点，非火工装置的这些优点正好是火工装置的不足之处，所以在不能使用火工装置的条件下可以考虑使用非火工装置。文章对接分离装置有一定的参考价值。     

航天火工技术的现状和发展

火工技术是航天工程中的关键技术之一,文章综述了国内、外航天火工技术的现状和发展趋势。重点介绍了火工装置的特性,几种新型起爆技术,索类火工装置,并讨论了火工装置研制中的一些问题以及可靠性技术,最后还提出了几点建议。     

An endogenous growth pattern of roots is revealed in seedlings grown in microgravity

In plants, sensitive and selective mechanisms have evolved to perceive and respond to light and gravity. We investigated the effects of microgravity on the growth and development of Arabidopsis thaliana (ecotype Landsberg) in a spaceflight experiment. These studies were performed with the Biological Research in Canisters (BRIC) hardware system in the middeck region of the space shuttle during mission STS-131 in April 2010. Seedlings were grown on nutrient agar in Petri dishes in BRIC hardware under dark conditions and then fixed in flight with paraformaldehyde, glutaraldehyde, or RNAlater. Although the long-term objective was to study the role of the actin cytoskeleton in gravity perception, in this article we focus on the analysis of morphology of seedlings that developed in microgravity. While previous spaceflight studies noted deleterious morphological effects due to the accumulation of ethylene gas, no such effects were observed in seedlings grown with the BRIC system. Seed germination was 89% in the spaceflight experiment and 91% in the ground control, and seedlings grew equally well in both conditions. However, roots of space-grown seedlings exhibited a significant difference (compared to the ground controls) in overall growth patterns in that they skewed to one direction. In addition, a greater number of adventitious roots formed from the axis of the hypocotyls in the flight-grown plants. Our hypothesis is that an endogenous response in plants causes the roots to skew and that this default growth response is largely masked by the normal 1?g conditions on Earth.     

Variations of ionospheric fluctuations of phase delay depending on solar activity: Data of the COSMIC experiment

We present the results of processing and analysis of more than 4500 events of radio occultation sounding of the Earth’s atmosphere observed in the course of the COSMIC experiment on the limb path ‘satellite-ionosphere-satellite’. Events observed in December 2011 (when a number of solar flares occurred) and in January 2012 (when a strong solar proton event took place) were analyzed. It is shown that small-scale variations of electron density increase in polar latitudes, equatorial region, and midlatitudes of the southern hemisphere in January 2012. In the same period, an increase of large-scale variations of electron density is observed during daylight hours in the equatorial region and in the southern hemisphere. No noticeable distinctions in comparison with days of quiet Sun were observed in December 2011.     

Nemaline rod and degeneration of Z band of muscle cell in weightlessness at spaceflight

There are some studies demonstrating the skeletal muscle degeneration associated with the degeneration of Z band and appearance of nemaline rods in experimental animals of the simulation model for spaceflight but not in human heart tissues. In the present study, therefore, we investigated the pathological changes or degeneration in left auricular heart muscles obtained during operations of mitral valves replacement using both electron and light microscopies. The degeneration of Z band even in the myofibrils of comparatively little damaged cell was found. Furthermore, nemaline rods were detected in most of the heart muscle cells. These results suggest that the existence of nemaline rods is involved in the cell injury in the heart muscle of patients with heart disease without nemaline myopathy. Further study is necessary to know whether the similar pathological findings are observed not only in the skeletal muscle but also in the cardiac muscle in experimental animals of the simulation model for spaceflight or in a prolonged spaceflight.     

The human cardiovascular system during space flight

Purpose of the work is to analyze and to summarize the data of investigations into human hemodynamics performed over 20 years aboard orbital stations Salyut-7 and Mir with participation of 26 cosmonauts on space flights (SF) from 8 to 438 days in duration. The ultrasonic techniques and occlusive plethysmography demonstrated dynamics of changes in the cardiovascular system during SF of various durations. The parameters of general hemodynamics, the pumping function of the heart and arterial circulation in the brain remained stable in all the space flights; however, there were alterations in peripheral circulation associated with blood redistribution and hypovolemie in microgravity. The anti-gravity distribution of the vascular tone decayed gradually as unneeded. The most considerable changes were observed in leg vessels, equally in arteries (decrease in resistance) and veins (increase in maximum capacity). The lower body negative pressure test (LBNP) revealed deterioration of the gravity-dependent reactions that changed for the worse as SF duration extended. The cardiovascular deconditioning showed itself as loss of descent acceleration tolerance and orthostatic instability in the postflight period.     

The Swedish Interplanetary Society (1950–1969) and the formation of IAF and IAA

With a growing interest for rocket technology and space travel after WW II a number of new “space societies” were formed in the period 1948–1951 in addition to the ones already existing in Germany, the UK and the US since before WW II. Soon came the need for a common international platform for exchange of information and experience, and the concept of an international federation of astronautical societies emerged.Sweden was one of the 8 countries to sign the original declaration to create an International Astronautical Federation on October 2, 1950 in Paris at the 1st International Astronautical Congress. The Swedish Society for Space Research (Svenska Sällskapet för Rymdforskning) was formed a few days after the historical event in Paris. The name was soon to be changed to the Swedish Interplanetary Society (Svenska Interplanetariska Sällskapet, SIS). Sweden was one of the 10 countries to sign the IAF foundation in 1951 in London and in the following year the first Constitution of IAF in Stuttgart.The SIS quickly grow to a membership of several hundred persons and its membership in IAF promoted an intensive exchange of journals, and the annual participation at the IAC gave growth to start study projects on spacecraft and sounding rockets, and the publication of astronautical journals in Swedish. In 1957 the first Swede was elected vice-president of IAF.Not too long after the IAF foundation the idea of an international body of distinguished individuals emerged, in addition to the body of "member societies" (IAF). Upon the initiative of Theodor von Karman, Eugen Sänger and Andrew Haley the IAF council approval of an International Academy of Astronautical was given on August 15, 1960 during the 11th IAC in Stockholm. This IAC in Stockholm gave a large publicity to space research and astronautics in Sweden, and put the activities of the SIS in the focus of the general public.This paper presents the Swedish involvement in the foundation of IAF and IAA. It also gives an overview on the positive influence of these two organisations on the work and progress of the Swedish Interplanetary Society and the diffusion of astronautics to the general public in Sweden.     

Changes in chromatin and nucleic acids in rat tissues after two-week spaceflight

The quantitative changes in nucleic acids and chromatin breakdown were followed in blood, thymus and spleen in rats after 14 day flights on board the biosatellites Cosmos-1887 and Cosmos-2044. Quantitative nucleic acid changes within 8-11 h after landing were only mild, most statistically non-significant. An analysis at 48 h after landing showed a marked decrease in a total content of DNA and RNA in spleen and thymus. Within 8-11 h after landing, the symptoms of chromatin breakdown were found as is seen in an increased concentration of its fragments-polydeoxyribonucleotides. The obtained results show that a partial adaptation to microgravity occurs up to flight day 14 in lymphoid organs. Adaptation is accompanied with a reappearing of the sensitive cells. Their chromatin breaks down, then, in a final phase of flight due to hypergravity stress manifesting itself by a temporary increase in polydeoxyribonucleotide concentration several hours after landing. The results are discussed in relation to the changes in chosen parameters after shorter or more prolonged flights.     

Developments in space activities in Poland

Poland has a long-standing tradition in space activities. Polish institutions have participated as co-investigators in almost all European Space Agency (ESA) science projects, as well as on many other missions. However, the first Polish satellite (PW-SAT) was only launched in 2012. Poland was one of the first Eastern European countries to conclude a Cooperation Agreement with ESA in the peaceful use of outer space; it was signed in 1994 and followed by a second in January 2002. Negotiations on Polish membership in the ESA were started in autumn of 2011, and ended in April 2012. Following ratification of the agreement, Poland officially became the 20th Member State of ESA on 19 November 2012. This article examines how Poland is setting its way as a space nation. It describes recent developments in the Polish space programme, including the road to Poland's full membership in the European Space Agency.     

Mineral and nitrogen balance study: results of metabolic observations on Skylab II 28-day orbital mission

Prediction that the various stresses of flight, particularly weightlessness, would bring about significant derangements in the metabolism of the musculoskeletal system has been based on various observations of long-term immobilized or inactive bed rest. The only attempt at controlled measurement of metabolic changes in space prior to Skylab, a study during the 14-day Gemini VII flight, revealed rather modest losses of important elements. The three astronauts of Skylab II consumed a planned day-by-day, quite constant, dietary intake of major metabolic elements in mixed foods and beverages and provided virtually complete collections of excreta for 31 days preflight, during the 28 days inflight, and for 17 days postflight. Analyses showed that, in varying degree among the crewmen, urinary calcium increased gradually during flight in a pattern similar to that observed in bed-rest studies: the mean plateau peak of urinary calcium excretion in the latter part of flight was double preflight levels. Fecal calcium excretion did not change significantly, but calcium balance, owing to the urinary calcium rise, became either negative or less positive than in preflight measurement. Increased excretion and negative balance of nitrogen and phosphorus indicated appreciable loss of muscle tissue in all three crewmen. Significant losses also occurred inflight in potassium, sodium, and magnesium. Based on the similarity in pattern and degree between these observations and those in bed rest of the losses in calcium, phosphorus, and nitrogen, musculoskeletal integrity would not be threatened in space flights of up to at least 3 months. However, if similar changes occur, indicative of continuing losses of these elements, in the planned Skylab flights for considerably more than 28 days, concern for capable musculoskeletal function should be serious for flights of very many months' duration, and greater research attention will need to be given to development of protective counter-measures.     

Serotonin in individual hypothalamic nuclei of rats after space flight on biosatellite Cosmos 1129.

The experiment on Cosmos 1129 was based on our results obtained in rats exposed to single or repeated restrain stress in the laboratory. These results have convincingly demonstrated a significant increase of serotonin concentration (5-HT) in the hypothalamus in acutely stressed rats. This response, which was found also in the isolated hypothalamic nuclei, was diminished in repeatedly (40 times) immobilized rats. While the concentration of 5-HT was unchanged in the majority of the hypothalamic nuclei of animals subjected to cosmic flight, an increase was recorded only in the supraoptic nucleus (NSO) and a decrease in the periventricular nucleus. These findings demonstrate that only few areas of the hypothalamus respond to cosmic flight with changes of 5-HT concentration and suggest either that long-term cosmic flight cannot be an intensive stressor or that during the flight the rats became already adapted to its long-term effect. However, the exposure of flight rats to repeated immobilization stress resulted in a significant increase of 5-HT in the NSO, para-ventricular and dorsomedial (NDM) nuclei. It should be noted that we have never seen any changes of 5-HT concentration, tryptophan hydroxylase and monoamineoxidase activities in repeatedly (40 times) immobilized rats. On the other hand, the increase of 5-HT concentration in the NDM is a typical finding after seven exposures of rats to immobilization on Earth, daily for 150 min. In the experiment COSMOS 1129 such an increase of 5-HT concentration in the NDM was found not only in the flight group but also in the control group of rats subjected to five daily exposures of immobilization stress. With respect to these findings, the increased 5-HT concentrations observed in some isolated hypothalamic nuclei in the flight group of rats exposed after landing to repeated immobilization stress suggest that long-term space flight and the state of weightlessness do not represent a stressogenic factor with respect to the serotoninergic system in the hypothalamus.     

Motion sickness susceptibility during rotation at 30 rpm in free-fall parabolic flight

Free fall per se whether in parabolic or orbital flight may be regarded as a "partial" motion environment with respect to eliciting motion sickness, requiring an additional component to render this environment "complete" or stressful. Parabolic flight in toto falls in the category of a "complete" motion environment in that some persons became motion sick with head fixed and eyes closed. In the present experiment we selected subjects who were symptom free or nearly symptom free in the KC-135 with head fixed. All tests were conducted with the subject rotating at 30 rpm in a rotating litter chair, and comparisons were made between head-fixed and head-moving conditions (right-left) in the free-fall phase of parabolic flight and under simulated free-fall phases in the laboratory. With head fixed most subjects were insusceptible; with head moving left-right susceptibility was slightly higher in the laboratory than aloft. An additional comparison was made correlating susceptibility in the free-fall phases of parabolic flight with susceptibility to experimental motion sickness in Skylab. In both situations cross-coupled angular accelerations were generated by executing head and body movements out of the plane of rotation. In parabolic flight 9 of 15 subjects reached an endpoint just short of frank motion sickness. In the Skylab workshop all eight of the astronauts tested were symptom free at the end of the test. The explanation for the difference in susceptibility rests in two factors: (1) Basic susceptibility in free fall is lower than on the ground, and (2) in Skylab the astronauts who needed to adapt had achieved this goal prior to the first test on Mission-Day 8.