The space life sciences strategy for the 21st century

In the past, space life sciences has focused on gaining an understanding of physiological tolerance to spaceflight, but, for the last 10 years, the focus has evolved to include issues relevant to extended duration missions. In the 21st century, NASA's long-term strategy for the exploration of the solar system will combine the assurance of human health and performance for long periods in space with investigations aimed at searching for traces of life on other planets and acquiring fundamental scientific knowledge of life processes. Implementation of this strategy will involve a variety of disciplines including radiation health, life support, human factors, space physiology and countermeasures, medical care, environmental health, and exobiology. It will use both ground-based and flight research opportunities such as those found in current on-going programs, on Spacelab and unmanned biosatellite flights, and during Space Station Freedom missions.     

A new cooperative strategy for space in the twenty-first century

The context within which the major government space programmes of the world are planned and obtain political approval has changed dramatically with the end of the Cold War. International economic competition has become a central issue in international affairs. Economic and political constraints require that space agencies adapt the ambitious plans they put forward in the 1980s to the realities of this decade and beyond. This paper argues that in this changed context, enhanced international space cooperation can make important contributions to advancing the core interests of nations and firms, and that in some situations, increased and more intimate cooperation may be the only way to achieve ambitious space goals. The paper contains a series of policy-oriented findings and recommendations that together comprise a ‘new cooperative strategy’ for space.     

A joint European strategy for space

This paper describes the background to the creation of the first coherent space strategy for Europe and explains why such a co-operative effort is necessary—in order to achieve strategic economic and security goals for the benefit of Europe's citizens. It discusses the three major objectives of the strategy and looks at the differing roles that will be played by ESA and the European Commission in its implementation, as well as at the developing relationship between the two bodies.     

Fluid inclusion studies of chemosynthetic carbonates: strategy for seeking life on Mars

Fluid inclusions in minerals hold the potential to provide important data on the chemistry of the ambient fluids during mineral precipitation. Especially interesting to astrobiologists are inclusions in low-temperature minerals that may have been precipitated in the presence of microorganisms. We demonstrate that it is possible to obtain data from inclusions in chemosynthetic carbonates that precipitated by the oxidation of organic carbon around methane-bearing seepages. Chemosynthetic carbonates have been identified as a target rock for astrobiological exploration. Other surficial rock types identified as targets for astrobiological exploration include hydrothermal deposits, speleothems, stromatolites, tufas, and evaporites, each of which can contain fluid inclusions. Fracture systems below impact craters would also contain precipitates of minerals with fluid inclusions. As fluid inclusions are sealed microchambers, they preserve fluids in regions where water is now absent, such as regions of the martian surface. Although most inclusions are < 5 microns, the possibility to obtain data from the fluids, including biosignatures and physical remains of life, underscores the advantages of technological advances in the study of fluid inclusions. The crushing of bulk samples could release inclusion waters for analysis, which could be undertaken in situ on Mars.     

A microbial oasis in the hypersaline Atacama subsurface discovered by a life detector chip: implications for the search for life on Mars

The Atacama Desert has long been considered a good Mars analogue for testing instrumentation for planetary exploration, but very few data (if any) have been reported about the geomicrobiology of its salt-rich subsurface. We performed a Mars analogue drilling campaign next to the Salar Grande (Atacama, Chile) in July 2009, and several cores and powder samples from up to 5?m deep were analyzed in situ with LDChip300 (a Life Detector Chip containing 300 antibodies). Here, we show the discovery of a hypersaline subsurface microbial habitat associated with halite-, nitrate-, and perchlorate-containing salts at 2?m deep. LDChip300 detected bacteria, archaea, and other biological material (DNA, exopolysaccharides, some peptides) from the analysis of less than 0.5?g of ground core sample. The results were supported by oligonucleotide microarray hybridization in the field and finally confirmed by molecular phylogenetic analysis and direct visualization of microbial cells bound to halite crystals in the laboratory. Geochemical analyses revealed a habitat with abundant hygroscopic salts like halite (up to 260?g kg(-1)) and perchlorate (41.13?μg g(-1) maximum), which allow deliquescence events at low relative humidity. Thin liquid water films would permit microbes to proliferate by using detected organic acids like acetate (19.14?μg g(-1)) or formate (76.06?μg g(-1)) as electron donors, and sulfate (15875?μg g(-1)), nitrate (13490?μg g(-1)), or perchlorate as acceptors. Our results correlate with the discovery of similar hygroscopic salts and possible deliquescence processes on Mars, and open new search strategies for subsurface martian biota. The performance demonstrated by our LDChip300 validates this technology for planetary exploration, particularly for the search for life on Mars.     

A Ticket pricing strategy for an oligopolistic space tourism market

It is important for any new launch system to develop a successful pricing strategy and to optimize launch system parameters to receive a high economic profit. A question arises, what will happen when an existing suborbital flight market (the first likely to be established in space) is interfered with by a new established orbital flight market for space tourism. There is a risk that the suborbital space tourism market could be almost instantly displaced when a product capable of reaching orbit was introduced. This is best discussed using the following three cases whose results are presented in this paper. Case A presents a ticket pricing strategy for a suborbital and orbital vehicle if the two vehicles do not compete in the same market. Case B shows the necessary ticket pricing strategy for a suborbital vehicle if there is competition from an orbital flight operator. However, the suborbital vehicle would not be able to keep up with a drop in ticket prices due to its obsolete characteristics. Thus, the suborbital vehicle would be forced to stop operation in the year when flight costs became higher than flight receipts as shown in case C.     

Return to the Moon: A sustainable strategy

On 14 January 2004 President George Bush announced his vision for space exploration, to include a human return to the Moon. He argued that, with a moderate increase in NASA's annual expenditure, such a return was possible. This paper is an exploration of how the President's space initiative can be realised on an international co-operative basis along similar lines to those already existing with the international space station (ISS). By abandoning the concept of a lunar landing as the major goal of a lunar programme, the initiative is made feasible. The three-stage plan here presented meshes with the currently evolving plans for the US space initiative to provide a realistic, affordable and sustainable strategy for manned lunar exploration. It represents a significant opportunity for the USA to unite and lead the world on this grand, civilisation defining adventure.     

Determination of the width of a corridor of re-entry into the atmosphere for the problem of launching a spacecraft into a circumplanetary orbit after braking in the atmosphere

A method of calculating the optimal trajectories of a spacecraft re-entry into the atmosphere is considered under the condition of minimization of a re-orbit burn at the apocenter of the segment of escape from the atmosphere and taking into account a constraint on the maximum overload.     

Drying as one of the extreme factors for the microflora of the atmosphere

An investigation of the effects of drying and drying-rewetting cycles under vacuum conditions of 10(-2) torr at -30 degrees C on conidia of the atmospheric strain Penicillium chrysogenum from 48-77 km heights, collected by meteorological rockets found that survival and restoration of the initial physiological properties were possible through some very efficient protective cellular mechanisms. Such adaptive possibilities explain the widespread diffusion of microbial cells throughout the biosphere of our planet.     

Transient flashes of electromagnetic radiation in the upper atmosphere

Experimental data related to electric discharges in the upper atmosphere are considered. These discharges occupy enormous volumes of the atmosphere (up to 1000 km³) and are accompanied by optical radiation (in the UV, optical, and IR ranges), and also by gamma-ray radiation. Possible physical processes responsible for the evolution of such discharges are also considered.     

When inspiration fails to inspire: A change of strategy for the US space program

A pressing issue facing the US space program is the projected shortfall in the skilled aerospace workforce, as the number of students in space-related fields wanes. This has prompted many to emphasize the rhetoric of inspiration that prevailed during the Cold War, at the expense of concrete arguments for space that are thought to be lackluster and insufficient. This essay argues that the logic of inspiration fails to consider the changed context and attitudes of this younger public. Instead, such an approach proves counterproductive in attracting generations compelled by a host of ideas, some incompatible with the rhetoric of competition and prestige that prevailed before. Arguments that draw attention to the pragmatic elements of space, and that successfully align space with the notions that make sense now, may in turn prove to be the solution to draw the best and the brightest to the space program.     

Extremophiles and the search for extraterrestrial life

Extremophiles thrive in ice, boiling water, acid, the water core of nuclear reactors, salt crystals, and toxic waste and in a range of other extreme habitats that were previously thought to be inhospitable for life. Extremophiles include representatives of all three domains (Bacteria, Archaea, and Eucarya); however, the majority are microorganisms, and a high proportion of these are Archaea. Knowledge of extremophile habitats is expanding the number and types of extraterrestrial locations that may be targeted for exploration. In addition, contemporary biological studies are being fueled by the increasing availability of genome sequences and associated functional studies of extremophiles. This is leading to the identification of new biomarkers, an accurate assessment of cellular evolution, insight into the ability of microorganisms to survive in meteorites and during periods of global extinction, and knowledge of how to process and examine environmental samples to detect viable life forms. This paper evaluates extremophiles and extreme environments in the context of astrobiology and the search for extraterrestrial life.     

Determining total ozone content in the atmosphere using satellite measurements

In this paper a simple method is presented which is applicable for fast determination of total ozone content in the earth atmosphere by using IR radiation intensity data from satellite measurements. The method is based on the property that transmittance of inhomogeneous atmosphere in the 9.6 μm band can be well approximated by the transmittance of a homogeneous ozone slab characterized by its effective pressure and temperature. The effective pressure and temperature were determined as mean values weighted by the average ozone profile of each season. The transmission functions were computed from an empirical formula. Free parameters in the formula were determined by a multiple regression scheme, on the basis of the transmittance data either measured in the laboratory or evaluated by computations using a line by line integration procedure. The main advantage of the described method is an easy and fast computation procedure. According to comparison with direct ozone sounding the accuracy is good enough: the average relative error lies between 5 and 7%.     

Mollusc-microbe mutualisms extend the potential for life in hypersaline systems

Metazoans in extreme environments have evolved mutualisms with microbes that extend the physical and chemical capabilities of both partners. Some of the best examples are bivalve molluscs in evaporite and hypersaline settings. Mollusc tissue is developmentally and evolutionarily amenable to housing vast numbers of symbiotic microbes. Documented benefits to the host are nutritional. Multiple postulated benefits to the microbes are related to optimizing metabolic performance at interfaces, where heterogeneity and steep gradients that cannot be negotiated by microbes can be spanned by larger metazoan hosts. A small cockle, Fragum erugatum, and its photosymbiotic microbes provide a remarkable example of a mutualistic partnership in the hypersaline reaches of Shark Bay, Western Australia. Lucinid bivalves and their endosymbiotic chemolithotrophic bacteria provide examples in which hosts span oxic/anoxic interfaces on behalf of their symbionts at sites of seafloor venting. Multiple lines of evidence underscore the antiquity of mutualisms and suggest that they may have played a significant role in life's first experiments above the prokaryotic grade of complexity. The study of metazoan-microbe mutualisms and their signatures in extreme environments in the geologic record will provide a significant augmentation to microbial models in paleobiology and astrobiology. There are strong potential links between mutualisms and the early history of life on Earth, the persistence of life in extreme environments at times of global crisis and mass extinction, and the possibilities for life elsewhere in the universe.     

A hydrothermal system associated with the Siljan impact structure, Sweden--implications for the search for fossil life on Mars

The Siljan ring structure (368 +/- 1.1 Ma) is the largest known impact structure in Europe. It isa 65-km-wide, eroded, complex impact structure, displaying several structural units, including a central uplifted region surrounded by a ring-shaped depression. Associated with the impact crater are traces of a post-impact hydrothermal system indicated by precipitated and altered hydrothermal mineral assemblages. Precipitated hydrothermal minerals include quartz veins and breccia fillings associated with granitic rocks at the outer margin of the central uplift, and calcite, fluorite, galena, and sphalerite veins associated with Paleozoic carbonate rocks located outside the central uplift. Two-phase water/gas and oil/gas inclusions in calcite and fluorite display homogenization temperatures between 75 degrees C and 137 degrees C. With an estimated erosional unloading of approximately 1 km, the formation temperatures were probably not more than 10-15 degrees C higher. Fluid inclusion ice-melting temperatures indicate a very low salt content, reducing the probability that the mineralization was precipitated during the Caledonian Orogeny. Our findings suggest that large impacts induce low-temperature hydrothermal systems that may be habitats for thermophilic organisms. Large impact structures on Mars may therefore be suitable targets in the search for fossil thermophilic organisms.     

Ascending flows in the solar atmosphere and formation of the solar wind

Some morphological features of solar magnetic fields in the chromosphere and corona are considered based on studying various observational data. These data are compared to the results of observation of the solar wind and interplanetary magnetic field, as well as to the data on fluxes of solar cosmic rays. New specific features are found in the solar wind structure, and new additional indications of sources of the solar wind are obtained. The properties of the active regions and coronal holes are considered. A model of the ascending stream-like plasma flow is suggested. It flows around the discrete arched magnetic field tubes in the solar atmosphere and stretches them out into interplanetary space.     

Porphyrin as an ideal biomarker in the search for extraterrestrial life

A key issue in astrobiological research is identifying target molecules that are unambiguously biological in origin and can be easily detected and recognized. We suggest porphyrin derivatives as an ideal target, because these chromophores are global in distribution and found in virtually all living organisms on Earth, including microorganisms that may approximate the early evolution of life on Earth. We discuss the inherent qualities that make porphyrin ideally suited for astrobiological research and discuss methods for detecting porphyrin molecules in terrestrial sedimentary environments. We present preliminary data to support the use of ToFSIMS as a powerful technique in the identification of porphyrins.     

Ballistics of a fragmenting meteor body with allowance made for ablation in the non-isothermal atmosphere. II

The second part of the work is devoted to studying the motion of fragmenting meteor bodies with ablation by fragments in a planet’s atmosphere, taking into account its non-isothermal character in altitude. The mechanical fragmentation of a meteoroid under the action of aerodynamic drag is considered in the context of statistical strength theory. An analytical solution for ballistics of a fragmenting body is obtained at a constant parameter of ablation. A theoretical analysis of the derived regularities is made and an example of their usage in the problem of a comet-asteroid hazard is presented.     

Ballistics of a nonfragmenting meteor body with allowance made for mass outflow in the non-isothermal atmosphere. I

The paper is devoted to studying the motion of meteor bodies with mass outflow in a planet’s atmosphere, taking into account the non-isothermal character of the latter. Analytical solutions are obtained at the constant parameter of mass outflow in the model of a nonfragmenting meteoroid. A theoretical analysis of the derived regularities of the ballistics of such bodies is presented.