Carbon dioxide removal system for closed loop atmosphere revitalization,candidate sorbents screening and test results

Due to the difficulty and expense it costs to resupply manned-spacecraft habitats, a goal is to create a closed loop atmosphere revitalization system, in which precious commodities such as oxygen, carbon dioxide, and water are continuously recycled. Our aim is to test other sorbents for their capacity for future spacecraft missions, such as on the Orion spacecraft, or possibly lunar or Mars mission habitats to see if they would be better than the zeolite sorbents on the 4-bed molecular sieve. Some of the materials being tested are currently used for other industry applications. Studying these sorbents for their specific spacecraft application is different from that for applications on earth because in space, there are certain power, mass, and volume limitations that are not as critical on Earth. In manned-spaceflight missions, the sorbents are exposed to a much lower volume fraction of CO₂ (0.6% volume CO₂) than on Earth.LiLSX was tested for its CO₂ capacity in an atmosphere like that of the ISS. Breakthrough tests were run to establish the capacities of these materials at a partial pressure of CO₂ that is seen on the ISS. This paper discusses experimental results from benchmark materials, such as results previously obtained from tests on Grade 522, and the forementioned candidate materials for the Carbon Dioxide Removal Assembly (CDRA) system.     

Low-energy Earth–Moon transfers involving manifolds through isomorphic mapping

Analysis and design of low-energy transfers to the Moon has been a subject of great interest for decades. Exterior and interior transfers, based on the transit through the regions where the collinear libration points are located, have been studied for a long time and some space missions have already taken advantage of the results of these studies. This paper is concerned with a geometrical approach for low-energy Earth-to-Moon mission analysis, based on isomorphic mapping. The isomorphic mapping of trajectories allows a visual, intuitive representation of periodic orbits and of the related invariant manifolds, which correspond to tubes that emanate from the curve associated with the periodic orbit. Two types of Earth-to-Moon missions are considered. The first mission is composed of the following arcs: (i) transfer trajectory from a circular low Earth orbit to the stable invariant manifold associated with the Lyapunov orbit at L₁ (corresponding to a specified energy level) and (ii) transfer trajectory along the unstable manifold associated with the Lyapunov orbit at L₁, with final injection in a periodic orbit around the Moon. The second mission is composed of the following arcs: (i) transfer trajectory from a circular low Earth orbit to the stable invariant manifold associated with the Lyapunov orbit at L₁ (corresponding to a specified energy level) and (ii) transfer trajectory along the unstable manifold associated with the Lyapunov orbit at L₁, with final injection in a capture (non-periodic) orbit around the Moon. In both cases three velocity impulses are needed to perform the transfer: the first at an unknown initial point along the low Earth orbit, the second at injection on the stable manifold, the third at injection in the final (periodic or capture) orbit. The final goal is in finding the optimization parameters, which are represented by the locations, directions, and magnitudes of the velocity impulses such that the overall delta-v of the transfer is minimized. This work proves how isomorphic mapping (in two distinct forms) can be profitably employed to optimize such transfers, by determining in a geometrical fashion the desired optimization parameters that minimize the delta-v budget required to perform the transfer.     

Assessment on the feasibility of future shepherding of asteroid resources

Most plausible futures for space exploration and exploitation require a large mass in Earth orbit. Delivering this mass requires overcoming the Earth's natural gravity well, which imposes a distinct obstacle to any future space venture. An alternative solution is to search for more accessible resources elsewhere. In particular, this paper examines the possibility of future utilisation of near Earth asteroid resources. The accessibility of asteroid material can be estimated by analysing the volume of Keplerian orbital element space from which Earth can be reached under a certain energy threshold and then by mapping this analysis onto an existing statistical near Earth objects (NEO) model. Earth is reached through orbital transfers defined by a series of impulsive manoeuvres and computed using the patched-conic approximation. The NEO model allows an estimation of the probability of finding an object that could be transferred with a given Δv budget. For the first time, a resource map provides a realistic assessment of the mass of material resources in near Earth space as a function of energy investment. The results show that there is a considerable mass of resources that can be accessed and exploited at relatively low levels of energy. More importantly, asteroid resources can be accessed with an entire spectrum of levels of energy, unlike other more massive bodies such as the Earth or Moon, which require a minimum energy threshold implicit in their gravity well. With this resource map, the total change of velocity required to capture an asteroid, or transfer its resources to Earth, can be estimated as a function of object size. Thus, realistic examples of asteroid resource utilisation can be provided.     

Applications of multi-body dynamical environments: The ARTEMIS transfer trajectory design

The application of forces in multi-body dynamical environments to permit the transfer of spacecraft from Earth orbit to Sun–Earth weak stability regions and then return to the Earth–Moon libration (L₁ and L₂) orbits has been successfully accomplished for the first time. This demonstrated that transfer is a positive step in the realization of a design process that can be used to transfer spacecraft with minimal Delta-V expenditures. Initialized using gravity assists to overcome fuel constraints; the ARTEMIS trajectory design has successfully placed two spacecrafts into Earth–Moon libration orbits by means of these applications.     

Observation of narrow energy spectrum electron flows on <Emphasis Type="Italic">the INTERBALL Tail Probe</Emphasis> and their possible relation with the spacecraft charging

The paper describes cases of observations of narrow energy spectrum electron flows up to 500 eV on the INTERBALL Tail Probe. About 30 events were registered in 1996 on the night side of the Earth predominantly in 03^h–06^h local time sector. Quasimonochromatic electrons (QME) were registered by all 8 spectrometer channels oriented along the spacecraft meridian with angles of the field of view centers relative to sunward direction from 11° to 169°. Quasimonochromatic electrons were observed simultaneously with large fluxes of high temperature magnetospheric electrons. The dependences of QME energy on both fluxes and energy of high-energy magnetospheric electrons were observed in every event. The ratio of full width at half height (FWHH) to mean energy of QME was ~20%. This electron component with quasimonochromatic energy probably was originated on the spacecraft surface. The registered energy of QME was apparently due to difference of potentials between spacecraft surface from which electron beam originated and the location of electron spectrometer.     

用于空间站火灾防护的隔绝式氧烛呼吸自救器研制

文章介绍某新型隔绝式氧烛呼吸自救器的研制.其呼吸保护装置主要由防护头罩、氯酸钠氧烛和CO2吸附3个单元组成,利用氧烛产生的O2通过文丘里管推动头罩内的空气循环,采用LiOH吸附剂吸附循环气体中的CO2.该装置进行了适用性试验,人体感觉良好.文章对该装置用于空间站火灾逃生自救的可行性进行了分析,认为其适用于空间站火灾逃生.     

The Indian EO Programme-national and global drivers

The Indian Earth Observations Program, over the past three decades, has been mainly driven by the national need for natural resources management, environment monitoring and disaster support. With an array of seven Indian Earth Observation Satellites, national development support has been provided through a well-knit institutional framework of a National Natural Resources Management System (NNRMS). A wide variety of applications have been developed as an inter-agency effort over the past 15 years. Now, the capacity of the programme has extended into the global arena and is providing operational data services to the global user community. Positioning of relevant policy guidelines for the EO program to contribute to national endeavor and its transitioning for global outreaching and development of a commercial enterprise — both at national and global levels has been an area of constant attention within ISRO.Issues related to defining the space and data acquisition as a national “public ground”, costing of data products and services and evolving a commercial Earth Observation policy have been addressed for providing the overall thrust of the Indian Earth Observations program. The paper discusses the evolution of the policy in the early stages and its transition today to support a two-pronged strategy of supporting national development support and at the same time, developing a commercial program. The paper also illustrates the success of these policy endeavors through specific cases of applications and development of value added services. The paper also brings out the potential policy adjustments that will be called for in the coming years.     

Activities of the COSPAR Panel on Exploration supporting the Global Exploration Roadmap

The Global Exploration Roadmap (GER) is driven by several goals and objectives that include space science, the search for life as well as preparatory science activities to enable human space exploration. The Committee on Space Research (COSPAR), through its Commissions and Panels provides an international forum that supports and promotes space exploration worldwide. COSPAR's Panel on Exploration (PEX) investigates a stepwise approach of preparatory research on Earth and in Low Earth Orbit (LEO) to facilitate a future global space exploration program. We summarize recent activities and workshops of PEX in support of the GER.     

A Magnetospheric Substorm and the Motion of the Magnetopause

Using a single event as an example, we make an analysis of the time development of a substorm and estimate its influence on the motion of the low-latitude boundary of the magnetosphere. To this end, we compare the data on plasma and magnetic field obtained by five spacecraft (WIND, INTERBALL-1, GEOTAIL, GOES-8, and GOES-9) with measurements made by ground-based stations. It is shown that the release of energy of the geomagnetic tail begins from a disruption of the current sheet near the Earth. The high-speed plasma stream that transfers a magnetic flux to the Earth and can have an effect on the magnetic field configuration near the Earth is detected later. Almost simultaneously with a substorm onset a series of magnetopause crossings has been detected by the INTERBALL-1 satellite on the evening side of the low-latitude magnetosphere. In this paper we consider some of possible causes of this motion of the magnetosphere boundary, including variations of parameters of the solar wind, Kelvin-Helmholtz instability, and substorm processes. It is shown that fast motions of the magnetopause are detected almost simultaneously with field variations in the near magnetotail of the Earth and geomagnetic pulsations Pi2 on ground-based stations. A sufficiently high degree of correlation (K = 0.67) between the amplitude of Pi2 pulsations and the amplitude of magnetic field variations near the magnetopause is probably indicative of the connection of short-term motions of the magnetosphere boundary with the tail current disruption and the process of formation of a substorm current wedge.__________Translated from Kosmicheskie Issledovaniya, Vol. 43, No. 4, 2005, pp. 248–259.Original Russian Text Copyright © 2005 by Nikolaeva, Parkhomov, Borodkova, Klimov, Nozdrachev, Romanov, Yermolaev.     

CCISS,Vascular and BP Reg: Canadian space life science research on ISS

A comprehensive goal of the Canadian Space Agency studies (CCISS, Vascular and BP Reg) has been to investigate the efficacy of current exercise countermeasures to maintain cardiovascular and cerebrovascular health on return to Earth after up to 6-months in space. Results from the CCISS experiments revealed no significant change of in-flight heart rate during daily activities or sleep, and small, but variable between astronauts, post-flight elevation. The between astronaut differences were exaggerated during measurement of spontaneous baroreflex slope, which was reduced post-flight (P<0.05) during paced breathing with 3 astronauts having significant correlations between reduced baroreflex and reduced RR-interval (consistent with reduced fitness). Cerebrovascular autoregulation and CO₂ response were mildly impaired after flight. Some loss of in-flight fitness of astronauts in Vascular was reflected by the increase in HR at a work rate of 161±46 W of 12.3±10.5 bpm, 10.4±5.9 bpm and 13.4±5.7 bpm for early-flight, late-flight and R+1, respectively. On return to gravity, changes in resting heart rate for supine (5.9±3.5 bpm), sit (8.1±3.3 bpm) and stand (10.3±10.0 bpm) were small but variable between individuals (from −5 bpm to +20 bpm in post-flight standing) and not related to the change in exercise heart rate. In Vascular astronauts, pulse wave transit time measured to the finger tended to be reduced post-flight and carotid artery distensibility was significantly reduced (P=0.03, and n=6). The heart rate and baroreflex data suggest that some astronauts return with cardiovascular deconditioning in spite of the exercise regimes. However, greater arterial stiffness is common among all astronauts studied to date. The new CSA project, BP Reg, will monitor inflight blood pressure in an attempt to identify astronauts in greater need for countermeasures. Future research should focus on whether Vascular changes in astronauts might make them an appropriate model to study the mechanisms of arterial aging on Earth.     

International coordination of space solar power related activities

Because the need for energy is global, and many energy networks are already interdependent, because no one country has sufficient technological capability or sufficient funds to provide a space solar powered solution on its own, and because any such solution will require international regulation, international coordination will be vital to any attempt to produce energy for Earth from space. This will be made easier by the fact that work on the subject has already been widely publicized and distributed and cooperative efforts have already been made. Various coordinating approaches are described and the need to forge partnerships between government, industry and academia — with greater involvement of all non-space groups concerned with energy — is emphasized. A “terracing approach” to the actual implementation of SPS is suggested and outlined.     

Advancing Earth observation from space: A global challenge

Global Earth observation goes well beyond taking pictures of the Earth from space. Earth observation aims to identify and characterize planetary-scale processes that occur in the Earth interior or the world's oceans, at the Earth's surface or within the global atmosphere, on the basis of weak signals that may be detected in space. This is a truly challenging task that requires the dedicated efforts of professionals and firm public support commitments. The article reveals the scope of global Earth observation, highlights the technical and managerial challenges involved in undertaking it and discusses ways of making it more effective. Competent international cooperation and cost-sharing arrangements are essential for the ultimate success of existing and future activities in this field.     

Manifold dynamics in the Earth–Moon system via isomorphic mapping with application to spacecraft end-of-life strategies

Recently, manifold dynamics has assumed an increasing relevance for analysis and design of low-energy missions, both in the Earth–Moon system and in alternative multibody environments. With regard to lunar missions, exterior and interior transfers, based on the transit through the regions where the collinear libration points L₁ and L₂ are located, have been studied for a long time and some space missions have already taken advantage of the results of these studies. This paper is focused on the definition and use of a special isomorphic mapping for low-energy mission analysis. A convenient set of cylindrical coordinates is employed to describe the spacecraft dynamics (i.e. position and velocity), in the context of the circular restricted three-body problem, used to model the spacecraft motion in the Earth–Moon system. This isomorphic mapping of trajectories allows the identification and intuitive representation of periodic orbits and of the related invariant manifolds, which correspond to tubes that emanate from the curve associated with the periodic orbit. Heteroclinic connections, i.e. the trajectories that belong to both the stable and the unstable manifolds of two distinct periodic orbits, can be easily detected by means of this representation. This paper illustrates the use of isomorphic mapping for finding (a) periodic orbits, (b) heteroclinic connections between trajectories emanating from two Lyapunov orbits, the first at L₁, and the second at L₂, and (c) heteroclinic connections between trajectories emanating from the Lyapunov orbit at L₁ and from a particular unstable lunar orbit. Heteroclinic trajectories are asymptotic trajectories that travels at zero-propellant cost. In practical situations, a modest delta-v budget is required to perform transfers along the manifolds. This circumstance implies the possibility of performing complex missions, by combining different types of trajectory arcs belonging to the manifolds. This work studies also the possible application of manifold dynamics to defining suitable, convenient end-of-life strategies for spacecraft orbiting the Earth. Seven distinct options are identified, and lead to placing the spacecraft into the final disposal orbit, which is either (a) a lunar capture orbit, (b) a lunar impact trajectory, (c) a stable lunar periodic orbit, or (d) an outer orbit, never approaching the Earth or the Moon. Two remarkable properties that relate the velocity variations with the spacecraft energy are employed for the purpose of identifying the optimal locations, magnitudes, and directions of the velocity impulses needed to perform the seven transfer trajectories. The overall performance of each end-of-life strategy is evaluated in terms of time of flight and propellant budget.     

International cooperation - how to proceed

As part of a project exploring ways that international cooperation can maximize the benefits of space activities in the new political climate of the 1990s, the American Institute of Aeronautics and Astronautics (AIAA) has been organizing expert workshops on the subject. The latest of these, held in December 1994, focused on five areas: global space systems services; human and robotic exploration; space transportation; solar power to Earth; and international peacekeeping. It is only in the last few years that recommendations on the latter topic could realistically have been put forward and, as a prelude to our presentation of the Executive Summary of the report produced by AIAA, two of the 60-plus participants drawn from 15 countries, Robert Fuhrmann and Jürgen Wild, discuss the implications of this new found openness over international security and analyse the background to its genesis.     

Determination of vibrational CO2 distributions in thermodynamically-nonequilibrated rarefied flows by use of radiational characteristics in the 15 μm band

A method for determination of the vibrational distributions and populations of individual vibrational levels of vibrationally-nonequilibrated carbon dioxide in bend-stretch manifold and asymmetric stretching mode was developed and substantiated. The method is based on the measurements of integrated radiation intensity in the wide spectral intervals of the 15 μm CO₂ band and total emissivities of its appropriate Q-branches. Computations of radiation intensities and emissivities in P and R-branches were performed by using vibrational-rotational band models and in Q-branches by the direct “line-by-line” integration.It was shown that vibrational temperature of CO₂ asymmetric stretching mode may be determined from the measurements of integrated radiation intensity of the 15 μm band. The populations of individual levels of the bend-stretch manifold may be obtained from the measurements of total emissivities of some Q-branches of the 15 μm band.The procedure of the CO₂ lower vibrational levels populations determination under the conditions typical of 18 μm and 9–11 μm CO₂ laser cavities is described.     

The Global Earth Observation System of Systems: Science Serving Society

Over the next decade, a Global Earth Observation System of Systems (GEOSS) will revolutionize our understanding of the Earth and how it works, producing societal benefits through more coordinated observations, better data management, increased data sharing and timely applications. The political momentum behind the establishment of GEOSS is described and examples of its benefits—drought prediction, disease monitoring, accuracy of weather and energy needs forecasting, disaster mitigation—are provided. While challenges exist, particularly in the area of making data accessible, steps are being taken to meet them, e.g. through the new GEO-Netcast concept. Interagency collaboration within countries is as important as international cooperation; the efforts of the US Group on Earth Observations in this regard are discussed. Maintaining the strong political support here and in all participating countries will be key to the success of GEOSS.     

Implications of an anthropic model of evolution for emergence of complex life and intelligence

Structurally complex life and intelligence evolved late on Earth; models for the evolution of global temperature suggest that, due to the increasing solar luminosity, the future life span of the (eukaryote) biosphere will be "only" about another billion years, a short time compared to the approximately 4 Ga since life began. A simple stochastic model (Carter, 1983) suggests that this timing might be governed by the necessity to pass a small number, n, of very difficult evolutionary steps, with n < 10 and a best guess of n = 4, in order for intelligent observers like ourselves to evolve. Here I extend the model analysis to derive probability distributions for each step. Past steps should tend to be evenly spaced through Earth's history, and this is consistent with identification of the steps with some of the major transitions in the evolution of life on Earth. A complementary approach, identifying the critical steps with major reorganizations in Earth's biogeochemical cycles, suggests that the Archean-Proterozoic and Proterozoic-Phanerozoic transitions might be identified with critical steps. The success of the model lends support to a "Rare Earth" hypothesis (Ward and Brownlee, 2000): structurally complex life is separated from prokaryotes by several very unlikely steps and, hence, will be much less common than prokaryotes. Intelligence is one further unlikely step, so it is much less common still.     

Space System for Detecting Hazardous Celestial Bodies Approaching Earth from the Daytime Sky (<Emphasis Type="Italic">SODA</Emphasis>)

The concept of the System for the Observation of Daytime Asteroids (SODA system) has been developed, the purpose of which is to detect at least 95% of hazardous celestial bodies larger than 10 m in size that fly towards Earth from the Sun side. Spacecraft, equipped with the optimum version, which has three wide-angle optical telescopes of small aperture (20–30 cm) will be placed in a halo orbit around the L₁ libration point of the Sun–Earth system. This will provide a warning on the hazardous object, approaching from the Sun side, and will allow one to determine the orbit and the point of body entering Earth atmosphere to a sufficient accuracy, at least a few hours before the body collides with Earth. The requirements to the system are considered, the results of a preliminary design of the set of instruments have been described, the areas of visibility are calculated, and the versions of data transmission modes have been proposed. It has been shown that, in cooperation with other (particularly ground-based) projects aimed to observing objects flying from the night sky side, it is possible to detect in advance all hazardous bodies in the near-Earth space larger than 10 m in size that approach Earth from almost any direction.     

Habitable zone limits for dry planets

Most discussion of habitable planets has focused on Earth-like planets with globally abundant liquid water. For an "aqua planet" like Earth, the surface freezes if far from its sun, and the water vapor greenhouse effect runs away if too close. Here we show that "land planets" (desert worlds with limited surface water) have wider habitable zones than aqua planets. For planets at the inner edge of the habitable zone, a land planet has two advantages over an aqua planet: (i) the tropics can emit longwave radiation at rates above the traditional runaway limit because the air is unsaturated and (ii) the dry air creates a dry stratosphere that limits hydrogen escape. At the outer limits of the habitable zone, the land planet better resists global freezing because there is less water for clouds, snow, and ice. Here we describe a series of numerical experiments using a simple three-dimensional global climate model for Earth-sized planets. Other things (CO(2), rotation rate, surface pressure) unchanged, we found that liquid water remains stable at the poles of a low-obliquity land planet until net insolation exceeds 415 W/m(2) (170% that of modern Earth), compared to 330 W/m(2) (135%) for the aqua planet. At the outer limits, we found that a low-obliquity land planet freezes at 77%, while the aqua planet freezes at 90%. High-obliquity land and aqua planets freeze at 58% and 72%, respectively, with the poles offering the last refuge. We show that it is possible that, as the Sun brightens, an aqua planet like Earth can lose most of its hydrogen and become a land planet without first passing through a sterilizing runaway greenhouse. It is possible that Venus was a habitable land planet as recently as 1 billion years ago.