Manifest complexity: A foundational ethic for astrobiology?

This paper examines the age old question of the basis of moral value in the new context of astrobiology, which offers a fresh perspective. The goal is to offer the broad outline of a general theory of moral value that can accommodate the diversity of living entities we are likely to encounter beyond the confines of Earth. It begins with ratiocentrism, the view that the possession of reason is the primary means by which we differentiate entities having moral value in and of themselves from those having moral value merely by virtue of the uses to which they can be put. I broaden this basis to include sociality and culture, arguing that these three attributes tend evolve as a “package deal.” Because of this, it's really the sociality-reason-culture triad (SRCT) which should be the criterion for intrinsic moral value. If the SRCT linkage is sufficiently strong, it follows that this sort of moral valuation would be shared by any non-human entities capable of reflection on the nature of such things, granting it a curious kind of objectivity. I then suggest that the unfolding of complexity produced by SRCT species may be the best means to realize the manifest destiny (manifest complexity) of all life, which could provide an ultimate, metaphysical foundation for ethical value. Finally, I outline how this new theory can be applied to different types of entities that we may encounter beyond Earth.     

A concept for NASA's Mars 2016 astrobiology field laboratory

The Mars Program Plan includes an integrated and coordinated set of future candidate missions and investigations that meet fundamental science objectives of NASA and the Mars Exploration Program (MEP). At the time this paper was written, these possible future missions are planned in a manner consistent with a projected budget profile for the Mars Program in the next decade (2007-2016). As with all future missions, the funding profile depends on a number of factors that include the exact cost of each mission as well as potential changes to the overall NASA budget. In the current version of the Mars Program Plan, the Astrobiology Field Laboratory (AFL) exists as a candidate project to determine whether there were (or are) habitable zones and life, and how the development of these zones may be related to the overall evolution of the planet. The AFL concept is a surface exploration mission equipped with a major in situ laboratory capable of making significant advancements toward the Mars Program's life-related scientific goals and the overarching Vision for Space Exploration. We have developed several concepts for the AFL that fit within known budget and engineering constraints projected for the 2016 and 2018 Mars mission launch opportunities. The AFL mission architecture proposed here assumes maximum heritage from the 2009 Mars Science Laboratory (MSL). Candidate payload elements for this concept were identified from a set of recommendations put forth by the Astrobiology Field Laboratory Science Steering Group (AFL SSG) in 2004, for the express purpose of identifying overall rover mass and power requirements for such a mission. The conceptual payload includes a Precision Sample Handling and Processing System that would replace and augment the functionality and capabilities provided by the Sample Acquisition Sample Processing and Handling system that is currently part of the 2009 MSL platform.     

An online astrobiology course for teachers

A continuing challenge for scientists is to keep K-12 teachers informed about new scientific developments. Over the past few years, this challenge has increased as new research findings have come from the field of astrobiology. In addition to trying to keep abreast of these new discoveries, K-12 teachers must also face the demands of the content and pedagogical goals imposed by state and national science education standards. Furthermore, many teachers lack the scientific content knowledge or training in current teaching methods to create their own activities or to implement appropriately new teaching materials designed to meet the standards. There is a clear need for special courses designed to increase the scientific knowledge of K-12 science teachers. In response to this need, the authors developed a suite of innovative, classroom-ready lessons for grades 5-12 that emphasize an active engagement instructional strategy and focus on the recent discoveries in the field of astrobiology. They further created a graduate-level, Internet-based distance-learning course for teachers to help them become familiar with these astrobiology concepts and to gain firsthand experience with the National Science Education Standards-based instructional strategies.     

Importance of a martian hematite site for astrobiology

Defining locations where conditions may have been favorable for life is a key objective for the exploration of Mars. Of prime importance are sites where conditions may have been favorable for the preservation of evidence of prebiotic or biotic processes. Areas displaying significant concentrations of the mineral hematite (alpha-Fe2O3), recently identified by thermal emission spectrometry, may have significance in the search for evidence of extraterrestrial life. Since iron oxides can form as aqueous mineral precipitates, the potential exists to preserve microscopic evidence of life in iron oxide-depositing ecosystems. Terrestrial hematite deposits proposed as possible analogs for hematite deposits on Mars include massive (banded) iron formations, iron oxide hydrothermal deposits, iron-rich laterites and ferricrete soils, and rock varnish. We report the potential for long-term preservation of microfossils by iron oxide mineralization in specimens of the approximately 2,100-Ma banded iron deposit of the Gunflint Formation, Canada. Scanning and analytical electron microscopy reveals micrometer-scale rods, spheres, and filaments consisting predominantly of iron and oxygen with minor carbon. We interpret these objects as microbial cells permineralized by an iron oxide, presumably hematite. The confirmation of ancient martian microbial life in hematite deposits will require the return of samples to terrestrial laboratories. A hematite-rich deposit composed of aqueous iron oxide precipitates may thus prove to be a prime site for future sample return.     

A perspective on the importance of reproductive mode in astrobiology

Reproduction is a vital characteristic of life, and sex is the most common reproductive mode in the eukaryotic world. Sex and reproduction are not necessarily linked mechanisms: Sexuality without reproduction exists, while several forms of asexual reproduction are known. The occurrence of sexuality itself is paradoxical, as it is very costly in evolutionary terms. Most of the hypotheses (more than 20) attempting to explain the prevalence of sex fall into two categories: Sex either creates good gene combinations for adaptation to environments or eliminates bad gene combinations counteracting the accumulation of mutations. In spite of this apparent wealth of beneficial effects of sex, asexuality is not rare. Most eukaryotic, asexual lineages are short-lived and can only persist through the presence of sexual roots, but at least two animal groups, bdelloid rotifers and darwinulid ostracods, seem to claim the status of ancient asexuals. Research on (a)sexuality is relevant to astrobiology in a number of ways. First, strong relationships between the origin and persistence of life in extreme environments and reproductive mode are known. Second, the "habitability" of nonterrestrial environments to life greatly depends on reproductive mode. Whereas asexuals can do equally well or better in harsh environments, they fail to adapt fast enough to changing abiotic and biotic environments. Third, it has been shown that plants reproduce mainly asexually in space, and sperm production and motility in some vertebrates are hampered. Both findings indicate that extraterrestrial life under conditions different from Earth might be dominated by asexual reproduction. Finally, for exchange of biological material between planets, the choice of reproductive mode will be important.     

Physical simulation for low-energy astrobiology environmental scenarios

Speculations about the extent of life of independent origin and the potential for sustaining Earth-based life in subsurface environments on both Europa and Mars are of current and relevant interest. Theoretical modeling based on chemical energetics has demonstrated potential options for viable biochemical metabolism (metabolic pathways) in these types of environments. Also, similar environments on Earth show microbial activity. However, actual physical simulation testing of specific environments is required to confidently determine the interplay of various physical and chemical parameters on the viability of relevant metabolic pathways. This testing is required to determine the potential to sustain life in these environments on a specific scenario by scenario basis. This study examines the justification, design, and fabrication of, as well as the culture selection and screening for, a psychrophilic/halophilic/anaerobic digester. This digester is specifically designed to conform to physical testing needs of research relating to potential extent physical environments on Europa and other planetary bodies in the Solar System. The study is a long-term effort and is currently in an early phase, with only screening-level data at this time. Full study results will likely take an additional 2 years. However, researchers in electromagnetic biosignature and in situ instrument development should be aware of the study at this time, as they are invited to participate in planning for future applications of the digester facility.     

Reassessing the possibility of life on venus: proposal for an astrobiology mission

With their similar size, chemical composition, and distance from the Sun, Venus and Earth may have shared a similar early history. Though surface conditions on Venus are now too extreme for life as we know it, it likely had abundant water and favorable conditions for life when the Sun was fainter early in the Solar System. Given the persistence of life under stabilizing selection in static environments, it is possible that life could exist in restricted environmental niches, where it may have retreated after conditions on the surface became untenable. High-pressure subsurface habitats with water in the supercritical liquid state could be a potential refugium, as could be the zone of dense cloud cover where thermoacidophilic life might have retreated. Technology based on the Stardust Mission to collect comet particles could readily be adapted for a pass through the appropriate cloud layer for sample collection and return to Earth.     

Supercooled water brines within permafrost-an unknown ecological niche for microorganisms: a model for astrobiology

This study describes brine lenses (cryopegs) found in Siberian permafrost derived from ancient marine sediment layers of the Arctic Ocean. The cryopegs were formed and isolated from sediment ~100,000-120,000 years ago. They remain liquid at the in situ temperature of -10 degrees C as a result of their high salt content (170-300 g/L). [(14)C] Glucose is taken up by the cryopeg biomass at -15 degrees C, indicating microbial metabolism at low temperatures in this habitat. Furthermore, aerobic, anaerobic heterotrophs, sulfate reducers, acetogens, and methanogens were detected by most probable number analysis. Two psychrophilic microbes were isolated from the cryopegs, a Clostridium and a Psychrobacter. The closest relatives of each were previously isolated from Antarctica. The cryopeg econiche might serve as a model for extraterrestrial life, and hence is of particular interest to astrobiology.     

Microbial populations in Antarctic permafrost: biodiversity, state, age, and implication for astrobiology

Antarctic permafrost soils have not received as much geocryological and biological study as has been devoted to the ice sheet, though the permafrost is more stable and older and inhabited by more microbes. This makes these soils potentially more informative and a more significant microbial repository than ice sheets. Due to the stability of the subsurface physicochemical regime, Antarctic permafrost is not an extreme environment but a balanced natural one. Up to 10(4) viable cells/g, whose age presumably corresponds to the longevity of the permanently frozen state of the sediments, have been isolated from Antarctic permafrost. Along with the microbes, metabolic by-products are preserved. This presumed natural cryopreservation makes it possible to observe what may be the oldest microbial communities on Earth. Here, we describe the Antarctic permafrost habitat and biodiversity and provide a model for martian ecosystems.     

Establishment of a rearing system of the extremotolerant tardigrade Ramazzottius varieornatus: a new model animal for astrobiology

Studies on the ability of multicellular organisms to tolerate specific environmental extremes are relatively rare compared to those of unicellular microorganisms in extreme environments. Tardigrades are extremotolerant animals that can enter an ametabolic dry state called anhydrobiosis and have high tolerance to a variety of extreme environmental conditions, particularly while in anhydrobiosis. Although tardigrades have been expected to be a potential model animal for astrobiological studies due to their excellent anhydrobiotic and extremotolerant abilities, few studies of tolerance with cultured tardigrades have been reported, possibly due to the absence of a model species that can be easily maintained under rearing conditions. We report the successful rearing of the herbivorous tardigrade, Ramazzottius varieornatus, by supplying the green alga Chlorella vulgaris as food. The life span was 35 +/- 16.4 d, deposited eggs required 5.7 +/- 1.1 d to hatch, and animals began to deposit eggs 9 d after hatching. The reared individuals of this species had an anhydrobiotic capacity throughout their life cycle in egg, juvenile, and adult stages. Furthermore, the reared adults in an anhydrobiotic state were tolerant of temperatures of 90 degrees C and -196 degrees C, and exposure to 99.8% acetonitrile or irradiation with 4000 Gy (4)He ions. Based on their life history traits and tolerance to extreme stresses, R. varieornatus may be a suitable model for astrobiological studies of multicellular organisms.     

一种新的重频特征识别方法

针对雷达脉冲重复间隔类型识别中存在的问题,提出了一种结合神经网络技术的重频识别方法.该方法分别对7种雷达重频模式,提出了新的特征矢量提取方法,并引用神经网络进行识别.实际仿真结果表明该方法是有效的,特别是对重频固定、重频滑变及重频抖动模式在高漏脉冲率的条件下依然具有较高的正确识别率.     

员工关系管理课程实践性教学的探讨

高职教育的目标是培养"实践能力强、具有良好职业道德的高技能应用型人才".高职教育中教学方法的选择直接影响培养学生实践能力的效果.笔者根据多年的教学经验,总结了课堂系统案例教学和实训相结合的实践性教学模式,将列举案例、讲评案例、讨论案例三种方式系统地运用到案例教学中,阐述了如何组织校内外实训及实训的方法,并对实践性教学的效果进行了分析,以利于更好地培养学生的实践能力.     

Automated payload and instruments for astrobiology research developed and studied by German medium-sized space industry in cooperation with European academia

For more than a decade Kayser-Threde, a medium-sized enterprise of the German space industry, has been involved in astrobiology research in partnership with a variety of scientific institutes from all over Europe. Previous projects include exobiology research platforms in low Earth orbit on retrievable carriers and onboard the Space Station. More recently, exobiology payloads for in situ experimentation on Mars have been studied by Kayser-Threde under ESA contracts, specifically the ExoMars Pasteur Payload. These studies included work on a sample preparation and distribution systems for Martian rock/regolith samples, instrument concepts such as Raman spectroscopy and a Life Marker Chip, advanced microscope systems as well as robotic tools for astrobiology missions. The status of the funded technical studies and major results are presented. The reported industrial work was funded by ESA and the German Aerospace Center (DLR).     

文献“Environmental Testing for Launch and Space Vehicles”[1]点评

作者根据多年的实践经验,对该文献中重要部分进行了点评,指出:空间系统的结构设计要"严格"按照环境设计来进行考核,而环境试验的目的除了筛选工艺质量之外,更重要的是验证设计载荷是否合理.文章还分别对声、振动和冲击试验中的关键步骤和内容进行了解析和说明.     

A management approach for allocating instrument development resources

The Cassini Science Management Plan was developed for NASA's Cassini mission to Saturn to assist the Science Instrument Manager in guiding the development of the spacecraft's science payload. This plan, unlike previous development approaches, allocated the entire mass, power, data rate and budget resources for the science instruments to the Principal Investigators. The result removed the Cassini Project from adjudicating and reallocating resources for instrument development problems. Instrument development problems that did occur were resolved by the Principal Investigators themselves through the use of a ‘resource exchange’. The exchange allowed Principal Investigators to submit ‘bids’ (i.e. a request for resources) to a database. Principal Investigators were allowed to barter their own resources with other investigators. The resulting exchange or multilateral trade allowed the investigators to reallocate their resource to ‘better’ their current position.     

Structural and functional changes in man accompanying the weightlessness in "Skylab" flights: a mathematical approach

The present paper reports a kinetic analysis of changes of some physiological parameters, obtained from international literature, after changes in gravitational environment. The overall phenomenology of the adaptation to weightlessness is characterized by a rapid process followed by a slow one. The two processes show half time values differing by about five times. Also in the case of readaptation to gravity, after recovery on the Earth, two well resolved processes, showing different half time values, are observed. It is of interest to notice that the rate of response to weightlessness is lower than that to gravity. Of course, the half time values observed depend on the different physiological parameters considered. In any case, the experimental data suggest a general trend of many adaptive changes, that may all be described by a simple mathematical model.     

一种星载计算机数据流软故障纠正算法

在太空环境中,由于宇宙射线的存在,计算机系统的存储单元经常发生各种瞬态故障。此类故障通常都使用硬件或从系统角度加以解决,但其成本高重量大。针对此种故障类型提出了一种软件实现的数据流故障纠正算法,该算法通过对程序中变量进行简单编码和解码操作后,可对发生在程序数据空间内的单“位”错误进行检测并进而纠正。故障注入的实验结果表明,对于程序数据段错误,该算法可把错误输出从原始程序的27％～49％降低到0．01％～0．02％,同时故障纠正率接近100％;对于程序堆栈段错误,该算法可把错误输出从原始程序的10％～70％降低到1％～3％,故障纠正率也在73％以上。与其它软件实现的软故障检测或纠正算法相比,实验结果表明该算法实现简单,运算量小,具有较高的错误探测与纠正能力。     

A fast numerical approach for Whipple shield ballistic limit analysis

Whipple shield is widely used on manned spacecraft, numerical simulation is an important way for obtaining the ballistic limit. The large population of particles and the large space span of Whipple shield simulation model restrict the computational efficiency. A fast numerical approach is presented for Whipple shield ballistic limit analysis. First, the critical penetration analysis of the rear walls is converted into specific impulse analysis delivered by the secondary debris cloud, because the maximum of specific impulse is the main determinant of the penetration. The dual plate simulation model is then converted into single plate model and the population of particles is reduced. Second, based on the isotropic expansion theory of secondary debris cloud, the specific impulse analysis is further converted into particle position and velocity analysis when the stable secondary debris formed. The space span of the simulation model is reduced. An example of Whipple shield ballistic limit analysis is provided for the verification of the fast numerical approach, it shows that this approach can significantly increase the computation efficiency with acceptable accuracy.