Thyrotropin receptor and membrane interactions in FRTL-5 thyroid cell strain in microgravity

The aim of this work was to analyze the possible alteration of thyrotropin (TSH) receptors in microgravity, which could explain the absence of thyroid cell proliferation in the space environment. Several forms of the TSH receptor are localized on the plasma membrane associated with caveolae and lipid rafts. The TSH regulates the fluidity of the cell membrane and the presence of its receptors in microdomains that are rich in sphingomyelin and cholesterol. TSH also stimulates cyclic adenosine monophosphate (cAMP) accumulation and cell proliferation. Reported here are the results of an experiment in which the FRTL-5 thyroid cell line was exposed to microgravity during the Texus-44 mission (launched February 7, 2008, from Kiruna, Sweden). When the parabolic flight brought the sounding rocket to an altitude of 264?km, the culture media were injected with or without TSH in the different samples, and weightlessness prevailed on board for 6 minutes and 19 seconds. Control experiments were performed, in parallel, in an onboard 1g centrifuge and on the ground in Kiruna laboratory. Cell morphology and function were analyzed. Results show that in microgravity conditions the cells do not respond to TSH treatment and present an irregular shape with condensed chromatin, a modification of the cell membrane with shedding of the TSH receptor in the culture medium, and an increase of sphingomyelin-synthase and Bax proteins. It is possible that real microgravity induces a rearrangement of specific sections of the cell membrane, which act as platforms for molecular receptors, thus influencing thyroid cell function in astronauts during space missions.     

Response to hypogravity of normal in vitro cultured follicular cells from thyroid

Aim of this investigation is the study of molecular modifications occurring in differentiated mammalian cells exposed to gravitational changes. The test system chosen is a well characterized clone of differentiated, normal thyroid follicular cells (FRTL5) in long-term culture. As a follow-up to our recent experiment performed during the MASER-7 sounding rocket mission, flown for European Space Agency by Swedish Space Corporation in May 1996, we evaluated FRTL5 cells responses to Thyroid Stimulating Hormone dependent cAMP production under acute hypogravity conditions obtained in a fast rotating clinostat. Following this approach, we evaluated the FRTL5 cells response to TSH under microgravity conditions in order to optimize experimental tools and strategies in preparation to, and in between real flight missions.     

深空探测器表面采样技术适应性研究

对探测器硬件表面的生物负载进行有效评估,是深空探测任务中行星保护的重要环节.文章对比了两种植绒拭子在不同材料表面对不同产芽孢菌的采集效率.结果显示,国产CY-93050T植绒拭子的采集效率高于ESA常用的Copan 552C植绒拭子,两者的平均采集效率分别为45.38％±13.46％和29.43％±8.2％;材料表面物...     

The benefits brought by space—General public versus space agencies perspectives

Space agencies and governments have been long striving to find justification for the budgets allocated to non-commercial space missions. The most frequent justifications were scientific discoveries, technological development as well as national prestige. The current study aims to have a different look at the question “Which are the benefits brought by space?” by investigating/sampling/interrogating the public opinion and identifying the perception and view of the generation that form the bulk of the taxpaying citizens for the immediate future and will be actively financing any future missions. The study focuses on the answers provided to an online survey by an international sample of population. The target individuals are in the age range of 25–44 and are users of social networks. They are either employed or students, but they are not directly involved with the space sector. The survey aims to establish whether the promotional activities of ESA, NASA and other space agencies are aligned with the perceived benefits of this sample population. Is space contributing to what the target people consider important? What could be done to improve/change this perception? How did the public perception evolve? Which are the biggest problems humanity is confronted with today according to the sample population? Could space help addressing these major problems? The paper will firstly present the statistical analysis of the sample answers and the conclusions that can be drawn from them. In a second step it will compare the perceptions and expectations of the public in regards to space with the current space agencies strategies and identify the gaps and discontinuities.     

Social and cultural issues during Shuttle/Mir space missions.

A number of interpersonal issues relevant to manned space missions have been identified from the literature. These include crew tension, cohesion, leadership, language and cultural factors, and displacement. Ground-based studies by others and us have clarified some of the parameters of these issues and have indicated ways in which they could be studied during actual space missions. In this paper, we summarize some of our findings related to social and cultural issues from a NASA-funded study conducted during several Shuttle/Mir space missions. We used standardized mood and group climate measures that were completed on a weekly basis by American and Russian crew and mission control subjects who participated in these missions. Our results indicated that American subjects reported more dissatisfaction with their interpersonal environment than their Russian counterparts, especially American astronauts. Mission control personnel were more dysphoric than crewmembers, but both groups were significantly less dysphoric than other work groups on Earth. Countermeasures based on our findings are discussed which can be applied to future multicultural space missions.     

Why we need a space elevator

The goals of and vision for development of a space elevator have been discussed repeatedly. However, why we should develop one has been glossed over. This paper will focus upon the major issue—why build a space elevator infrastructure? It considers why we need a space elevator, what missions it would enable and how far it would reduce costs. There is no doubt that some major missions would be enhanced or significantly enabled by a space elevator infrastructure. Global communications, energy, monitoring of the Earth, global/national security, planetary defense, and exploration beyond low-Earth orbit are a few examples. In the end, if we are serious about extending space development and avoiding limitations on the human spirit, the reason we should build a space elevator is because we must!     

Psychosocial interactions during ISS missions

Based on anecdotal reports from astronauts and cosmonauts, studies of space analog environments on Earth, and our previous research on the Mir Space Station, a number of psychosocial issues have been identified that can lead to problems during long-duration space expeditions. Several of these issues were studied during a series of missions to the International Space Station. Using a mood and group climate questionnaire that was completed weekly by crewmembers in space and personnel in mission control, we found no evidence to support the presence of predicted decrements in well-being during the second half or in any specific quarter of the missions. The results did support the predicted displacement of negative feelings to outside supervisors among both crew and ground subjects. There were several significant differences in mood and group perceptions between Americans and Russians and between crewmembers and mission control personnel. Crewmembers related cohesion to the support role of their leader, and mission control personnel related cohesion to both the task and support roles of their leader. These findings are discussed with reference to future space missions.     

Ethical problems of interaction between ground-based personnel and orbital station crewmembers.

Manned missions onboard orbital stations Salyut-6 and Salyut-7 have led us to the conclusion that a long-term space mission can be viewed as a complex socio-man-machine system whose effectiveness largely depends on the quality of interaction between its subsystems. When analyzing and assessing the reliability of this system, it is important to consider ethical aspects, because they concern human relations, permeating its very component and in the long run determining its efficiency. Psychological and medical examinations before, during and after manned missions have helped us to identify the major points of interaction of the subsystems which require adequate monitoring and optimization using socio-psychological and organization-technical approaches: arrangement and evaluation of the quality of work, arrangement of proper leisure, psychological comfort in the interpersonality and intergroup relations during prolonged space missions. This paper also discusses adaptive changes in the mental and physical state due to prolonged exposure to space flight factors such as microgravity and confinement.     

火星载人探测中辐射防护综述

火星探测是人类太空探索的重要组成部分,火星载人探测中航天员的辐射安全问题是人们最为关心的问题。文章扼要介绍了美国/俄罗斯火星载人探测技术的发展过程,重点阐述了探测中的辐射环境、辐射效应以及国外探测结果;在此基础上,对火星探测中的辐射剂量进行了预示,提出了辐射防护建议。     

Haploid deletion strains of Saccharomyces cerevisiae that determine survival during space flight

This study identifies genes that determine survival during a space flight, using the model eukaryotic organism, Saccharomyces cerevisiae. Select strains of a haploid yeast deletion series grew during storage in distilled water in space, but not in ground based static or clinorotation controls. The survival advantages in space in distilled water include a 133-fold advantage for the deletion of PEX19, a chaperone and import receptor for newly- synthesized class I peroxisomal membrane proteins, to 77–40 fold for deletion strains lacking elements of aerobic respiration, isocitrate metabolism, and mitochondrial electron transport. Following automated addition of rich growth media, the space flight was associated with a marked survival advantage of strains with deletions in catalytically active genes including hydrolases, oxidoreductases and transferases. When compared to static controls, space flight was associated with a marked survival disadvantage of deletion strains lacking transporter, antioxidant and catalytic activity. This study identifies yeast deletion strains with a survival advantage during storage in distilled water and space flight, and amplifies our understanding of the genes critical for survival in space.     

How shall we live in space? Culture, law and ethics in spacefaring society

The US civilian space program is focused on planning for a new round of human missions beyond Earth orbit, to realize a ‘vision’ for exploration articulated by President George W. Bush. It is important to examine this ‘vision’ in the broader context of the global enterprise of 21st century space exploration. How will extending a human presence into the Solar System affect terrestrial society and culture? What legal, ethical and other value systems should govern human activities in space? This paper will describe the current environment for space policy making and possible frameworks for future space law, ethics and culture. It also proposes establishment of a World Space Conference to aid deliberations on the above.     

Stepping stones toward global space exploration

Several nations are currently engaging in or planning for robotic and human space exploration programs that target the Moon, Mars and near-Earth asteroids. These ambitious plans to build new space infrastructures, transport systems and space probes will require international cooperation if they are to be sustainable and affordable. Partnerships must involve not only established space powers, but also emerging space nations and developing countries; the participation of these new space actors will provide a bottom-up support structure that will aid program continuity, generate more active members in the space community, and increase public awareness of space activities in both developed and developing countries. The integration of many stakeholders into a global space exploration program represents a crucial element securing political and programmatic stability. How can the evolving space community learn to cooperate on a truly international level while engaging emerging space nations and developing countries in a meaningful way? We propose a stepping stone approach toward a global space exploration program, featuring three major elements: (1) an international Earth-based field research program preparing for planetary exploration, (2) enhanced exploitation of the International Space Station (ISS) enabling exploration and (3) a worldwide CubeSat program supporting exploration. An international Earth-based field research program can serve as a truly global exploration testbed that allows both established and new space actors to gain valuable experience by working together to prepare for future planetary exploration missions. Securing greater exploitation of the ISS is a logical step during its prolonged lifetime; ISS experiments, partnerships and legal frameworks are valuable foundations for exploration beyond low Earth orbit. Cooperation involving small, low-cost missions could be a major stride toward exciting and meaningful participation from emerging space nations and developing countries. For each of these three proposed stepping stones, recommendations for coordination mechanisms are presented.     

Psychosocial issues affecting crews during long-duration international space missions

Psychosocial issues can negatively impact on crew performance and morale during long-duration international space missions. Major psychosocial factors that have been described in anecdotal reports from space and in studies from analog situations on Earth include: 1) crew heterogeneity due to gender differences, cultural issues, and work experiences and motivations; 2) language and dialect variations; and 3) task versus supportive leadership roles. All of these factors can lead to negative sequelae, such as intra-crew tension and cohesion disruptions. Specific sequelae that can result from single factors include subgrouping and scapegoating due to crew heterogeneity; miscommunication due to major or subtle language differences; and role confusion, competition, and status leveling due to inappropriate leadership role definition. It is time to conduct research exploring the impact of these psychosocial factors and their sequelae on space crews during actual long-duration international space missions.     

T cell regulation in microgravity – The current knowledge from in vitro experiments conducted in space,parabolic flights and ground-based facilities

Dating back to the Apollo and Skylab missions, it has been reported that astronauts suffered from bacterial and viral infections during space flight or after returning to Earth. Blood analyses revealed strongly reduced capability of human lymphocytes to become active upon mitogenic stimulation. Since then, a large number of in vitro studies on human immune cells have been conducted in space, in parabolic flights, and in ground-based facilities. It became obvious that microgravity affects cell morphology and important cellular functions. Observed changes include cell proliferation, the cytoskeleton, signal transduction and gene expression. This review gives an overview of the current knowledge of T cell regulation under altered gravity conditions obtained by in vitro studies with special emphasis on the cell culture conditions used. We propose that future in vitro experiments should follow rigorous standardized cell culture conditions, which allows better comparison of the results obtained in different flight- and ground-based experiment platforms.     

Psychological adaptation and salutogenesis in space: Lessons from a series of studies

Individuals who adapt positively to an inhospitable or extreme environment can derive benefit from their experiences. This positive effect may include an initial improvement in mental health as someone adjusts to the environment (adaptation) as well as more sustained personal growth during the mission (salutogenesis). We review relevant findings from our prior work, including two post-mission surveys of astronauts and cosmonauts, and three studies of crewmembers during missions in a space station simulator, the Mir space station, and the International Space Station (ISS). We also present new analyses showing evidence for adaptation to ISS missions. This finding replicates our previous results from the simulation study, but this effect was not found on the Mir. A better understanding of psychological adaptation and salutogenesis during space flight should help us develop strategies to enhance crewmembers’ in-flight stress tolerance and post-flight adjustment.     

Food for thought--nutritional problems in space

The present paper discusses how the study of nutritional problems in space have proceeded, the way microgravity may alter nutritional requirements and how these may be met during long term missions in space.     

Exobiological investigations on Russian spacecrafts

To investigate the possibility of prebiotic synthesis of organic molecules in open space, conditions involved irradiating nucleosides and inorganic phosphate during five Earth-orbiting Russian space missions that included Salut-7 (13- and 16-month missions), Mir, Bion-11, and Cosmos-2044. Dry films of samples were exposed from 2 weeks up to 16 months to the entire set of factors encountered in open space during Earth-orbiting missions. After each mission, products synthesized during flight and any compounds that remained undegraded were analyzed. The analyses demonstrated that increased flight duration led to the decay of both synthesized nucleotides and initial nucleosides. Corresponding laboratory experiments indicated that infrared radiation caused the greatest amount of decay to products of prebiotic reactions. Experiments revealed that 5'-mononucleotides were the main chemical products of the major derivatives synthesized of certain nucleosides. Exposure to ultraviolet (UV) C(145) was more effective than UVC(254) in producing a comparatively higher yield of mononucleotides, while the energy flux of the latter was one order of magnitude less (10(-7) as compared with 10(-6) for UVC(145)). In the course of the laboratory simulation experiments the heating of solid samples yielded the greatest production amount (6.34% for adenosine derivatives).     

From suborbital space tourism to commercial personal spaceflight

Excellent essays have been recently published on the profitability and the future of space tourism. This paper is intended to supplement the considerations in this field and emphasizes the further potential evolution of commercial personal spaceflights. Indeed, based upon work done at the International Space University (ISU) the oligopolistic character of suborbital space tourism has been linked to marketing and product life cycle (PLC) considerations and has led to the thesis that space tourism as a profitable sector will require a follow-on strategy. Orbital space tourism, on one hand, could become an extension of the PLC but, on the other hand, it is assumed that point-to-point (P2P) commercial space transport will become the long term sustainable market. Without ignoring technical challenges, this paper will mainly concentrate on marketing and commercial aspects of personal spaceflight.     

地月平动点轨道应用与研究进展

面向未来月球和深空探测任务的需求,调研了地月平动点应用与研究的国内外现状与进展,着重分析了近年来的研究方向、研究内容、技术方法与特点,提出了面向未来月球和深空探测任务的地月平动点应用构想,梳理总结了需解决的相应关键技术,可为未来平动点相关研究与应用提供有益借鉴,以及为我国后续月球和深空探测任务的规划与论证提供参考。